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Dyntopo Sculpting questions?
Does using dyntopo in sculpting mode give the best results? When is dyntopo the most necessary? Can you make your mesh revert to less vertices after using dyntopo? basically a smoother surface, the way it looked before checking dyntopo?
I also got a warning message saying "Dyntopo will not preserve vertex colors, uvs or other custom data." And another one saying "Keeping the modifiers will increase polycount when returning to object mode."
I will appreciate any advice.

You should only use Dynamic Topology if you make major changes to your mesh, especially if you want to expand an area out effectively changing the necessary Topology. Also you should avoid using Dyntopo if you use UVs and never use it with Subsurface on a mesh, because it works with triangles instead of quads.
For Example if you have a Cube and you want to add details on it you could do it with dyntopo if you don't bother with UVs Vertex Colors and Modifiers like the Subsurface Modifier  but if you want to use any of it its not recommended. UVs can of course be added later on in the process but that more difficult for a triangle mesh than for a quad mesh (at least in my opinion). But there aren't only negatives to Dyntopo. For Example you want to make that same Cube but for a Game. Then it needs to have the least amount of triangles possible. Dyntopo adds only vertices where you need them, where the other way of doing it with a Multiresolution Modifier would add a lot of vertices everywhere to get the same level of detail, while keeping the topology. Also you could only use dyntopo if you want to sculpt something like a human from just a cube, because you don't have the correct topology for a human in a Cube

Dyntopo is for prototyping, major clay reworking of an object sculpt that needs more constant tesselation where there form/detail is added as the artist sculpts. Best workflow is to work out the model base to start from, sculpt with dyntopo to get the best form, retopologize to get a simpler all quad mesh. The new mesh can then be unwrapped for UV textures and adding a multiresolution modifier can allow more fine detail sculpt in the new mesh, and eventual baking to get bump/displacement/normal mapping.
I use dyntopo as live clay in this method.


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scaling mesh and armature
Okay, so I've downloaded a mesh from a website for practice and the mesh itself has an armature. Now I want to know if I were to scale a certain part of the mesh's body to make it be taller, like the arms or legs, will it affect the armature bones in any way? Will the bones have to be adjusted to fit the mesh's body? or will the bones scale along with what ever part of the mesh is being scaled?
I will appreciate any advice thanks.

it should work but just try it on a copy

The bone wouldn't follow your modifications in edit-mode (unless maybe with specific constraints, which you would have to set manually).
So the bone would have to be manually adjusted (in edit-mode, not pose-mode) to follow.
Another approach would be to modify (scale for example) your bone in pose-mode. The associated parts of the mesh would follow the bone (if your vertex groups/bones associations are set up properly).
It's not easy to give you an "advice" because we don't really know what you want to do. You're only asking "If I do A, does it imply B ?". So answers are limited to yes/no.
For an advice, you should probably directly ask something like "In the context C, what are my options for doing D ?". Here we have part of C, but no real idea about D.

That solution doesn't work lately. The scaled object is considered a "pose". And so you can't apply the scale to it without jumbling the pieces. And if you try to set the new scaled object as the reset pose, it also jumbles the objects. Maybe Blender changed it. I've been all over, and so far no one has a simple way to just scale the bones and mesh the same, and end up being able to apply the scale so all are 1 when you are done.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

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UV unwrapping question
I've created a character mesh, but I still have certain parts to tweak like the face for an example and still have to decide how I want it to look. Is it safe to edit a mesh/model after uv unwrapping it?

I'd say no, not safe. Operations like Knife cut or Loopcut and another few allow to preserve UV after editing, but most modeling tools will modify your UV in a bad way.

Hey, thanks for clearly answering my question.

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Is it possible to Highlight all Animation keyframes in the dope sheet and make all frames stick to a specific location, all at once?
I downloaded two animations from Mixamo and imported it into blender. Both animations are an idle animation and a random action animation. The action animation starts at a completely different location when compared to idle animation that starts right in the middle location of x,y, and z.
This action animation has over 40 key frames and was wondering if its possible for me to highlight all keyframes of the animation and change all frames of the animation to be in the same location at once. This is so I don't have to change the location of every frame individually. Would appreciate any help.

If they didn't use the root bone in the animation, you could delete the keyframe for the root bone's location on both actions/animations, then move them where they need to go.  Won't work well if they used the root bone as part of the animation though, so make a copy file first.

Thanks for letting me know.

I'd do as @Policesate suggests, make a backup of the original Blend file, then - Try making a master parent for the model.  From there the included animations should become local to the parent.  Either enter in your desired location for the parent or simply drag it there - keyframe that.
The included animations should stay with it.  If they've keyframed the root bone, and it takes the model somewhere else for the idle state or other action, go into the Graph editor and drag all of that action's X/Y keyframes up or down to drag it back.  Press G Y to ensure you don't drift sideways in the editor.

Thanks for your reply. I'm going to try this.

Any problems, just ask...

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Extracting exact distance information for an animation
so basically what I want to do is have the exact distance between my Camera and an object, preferably in the metric system, for every frame of my animation.
I have been looking into the camera properties but can not seem to find anything for that, i have managed to change the units to metric but that's about it.

does the object you want the camera to stay relative to move?

You can use the "MeasureIt" add-on: enable it from the user preferences.
Then select your two objects and, from the left panel of the 3D viewport (T), look for "MeasureIt" and click on "Link" under the "Add measure" box. Then hit "Show" to visualize it, if it isn't displayed already.


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Modeling a Game character
Im new to Blender, and want to try out making a game character.
My question is, is scultping easier to do? And when I sculpt a model, do I HAVE to do the retopology after to make it animated, or is that just something some people prefer to do?
Thanks! :)

Sculpting is often used for giving the mesh different details, starting from basic shape and silhoutte and up to small cracks, lines etc. To do that you need high polycount in order sculpting to work (as it needs geometry). Game needs lowpoly model. So likely yes, you need to do retopology on the sculpted model. Though your question is too broad for this site so far (e.g. sculpting could be used like Proportional edit etc, hence it's better to tell you need retopo for high poly object), for discussions like this try https://blenderartists.org/


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Which color space should I use for 16-bit maps?
Many people recommend using 16-bit images for displacement and normal maps.
If I want to create my own displacement maps in, say, Photoshop, which color space should I use? Is 16-bit sRGB okay?
Does Blender assume a particular color space or does it detect it in the image file itself?

If I want to create my own displacement maps in, say, Photoshop, which color space should I use? Is 16-bit sRGB okay?

The term "sRGB" is thrown around far too frequently without an understanding as to what it means.
The best way to think about things like displacement maps and such, is that in many instances they are data, akin to units of measurement. That is, they are not colours.
This means that when you are building data in another application, it should be saved as such. Most image file formats are of course designed to encode colours. The sRGB specification, being designed for images, was likewise designed for colour encoding, not data.
Having data means that in many to most instances, one requires the encoded values to reflect a linear proportion, just as we would expect a ruler to have uniformly distributed markings. If we had a ruler with erratic / nonlinear markings, even if we re-distributed the measurements we took with such a ruler to be evenly distributed, the data would reflect overly sparse or overly dense regions based on the original erratic / nonlinear measurements. As a result, most image formats, being designed for nonlinear colour encoding, exhibit this behavior and are a poor choice as a result.
EXRs on the other hand, were designed from the ground up to encode data, including colour data. By convention, data encoded into an EXR is typically linear ratios, making it a great fit for data.
Being a display referred application designed for manipulating... Well... Photographs, Photoshop tends to be a sub-optimal solution here. Even PS's EXR support has been awful for a long time. Thankfully, FNordware has a useful plugin to use. There are plenty of PS "gotchas" though, so be careful and learn more about colour space encodings and colour management to give you control.

Does Blender assume a particular color space or does it detect it in the image file itself?

Unlike graphic design applications that have an ICC Colour Management System in place, Blender utilizes OpenColorIO, which is designed to make very few assumptions about encoded data. It leans heavily on encoded data format detection and defaults, as well as filename support, which will hopefully land in Blender proper soon.
It makes assumptions based on the encoding format of the data. If it is 8 bit or 16 bit integer (non-decimal), it will assign a default transform, which is currently only the sRGB transfer function. This may be inappropriate depending on context.
If the file is encoded as 16 bit or 32 bit float (decimal) such as the data in an EXR, the default transform will be set to "Linear", which is also a colour format. When loading data, change the transform to be "Non-Color Data".


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Can you get the distance from another object with nodes?
It's easy to get the distance from the origin of an external object by using the "Object" option in the Texture coordinate (through a Vector Math node set to Length).
But what if I want the distance from the surface of another object (so specifically from the closest point on the surface of another object)?
For example, I could use this value to generate complex volumetric shapes by modeling a very simple mesh and doing the rest with nodes (which is what I want to do).
I could do with either the distance itself or the vector coordinates of the closest point on the surface of an external mesh, either would be appreciated.
I apologize if there's an obvious solution or there's another question answering this on the site, but I was unable to find a solution on the web.

I'd say no, its not possible. A shader node tree linked to one mesh does not see the surface of another mesh. You can use other tools for that such as Animation Nodes that can make the surface proximity calculations and reflect it to the shader nodes.

You can do it mathematically if the other object is a very simple shape (cube, sphere, etc.) and you would have to do it manually for every object, but no, the shader itself can't trivially access information about the other objects in the scene

This may help out.
https://blender.stackexchange.com/questions/247657/is-it-possible-to-calculate-the-distance-between-the-vertices-of-two-objects-in


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Smoothing corners in mesh
Any modelling experts? I have a mesh that even with Object smoothing On and Normals Auto UV Off has sharp corners (circled green in attached). Is there anything I can do other than remodeling from scratch (was a purchased asset)

Try to add "Subdivision Surface" Modifier.

Thanks! I guess not the same as right clicking choosing 'Subdivide'


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Can I only Render light that psses through an object?
In the image below I would like only the light that passes through the sphere, in this case the bright dot in the center, to be visible. Is there a way to set this up in cycles?

Thanks,
Tyler

The bright light in your image is caused by Caustics but unfortunately there is no easy way (that I'm aware of) to render just the caustics from the image - and they are switched on/off via the Render properties so are not configurable via Scene or Render Layer. The only method I know that would allow you to do this would be to render the image once with Caustics enabled and again with Caustics disabled - then use the compositor to subtract the non-caustic image from the one with caustics, resulting in just the caustics left behind. If this sounds like a viable solution I can write an answer.

See this .blend file. I used nodes with the Transmission Depth node and two emission shaders joined with a mix shader. Set the green one to 0 strength and it should have the desired effect. I'll post a screen shot of the node set up in a moment. (The node set up for the lamp. It's a point source directly above the glass sphere.)
Here is the node set up.

The green is what will go away. The pink it what will be rendered.

Green disabled (strength is set to 0).


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BGE and Databases
I'm hoping to use Blender and the BGE in a bit of an unusual way.  I am hoping to create an interactive floor plan where I can click on desks and that will present information about the user.
Now I was hoping to store the data in an SQL database.  Is this possible to do?  I have even looked at the possibility of using Blender4Web to run in browser rather than having to run a seperate .exe each time.
If this may even be slightly possible are there any examples?
Many Thanks
Jon

If you are just using BGE then any Python code you can write will work, connecting/reading/writing to a database. As far as I can tell Blend4Web uses JavaScript in place of python and should  be able to load extra javascript that would interface via http/s to a web service with a database behind it. But I cannot see any direct examples.

As mentioned in the comment, the BGE has no build-in connection to databases.
You can use all Python libraries you like. Be aware you need to distribute them with your final application.
I know it is not a step-by-step instruction, but it is a big topic ... at a python forum.


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How to disable motion blur on a single object in Blender 2.8 EEVEE?
How to disable motion blur on a single object in Blender 2.8 EEVEE ?

The motion blur currently available in Eevee is camera based.
That means it compares the entire image between two frames and blurs all motion, it is not capable of blurring single objects.


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Rotated Gradient Blur in Compositor
I have a rendered image (actually sequence of images) and want to 'fake' a depth of field in the compositor by using a blur, or a defocus. My preconceived notion was that I should produce a gradient texture and use either the blur node and a color mix to combine the unblurred and blurred versions according to a factor prescribed by the gradient texture, or use a defocus node with the Z factor prescribed by the gradient. However, this seems much harder than it should be for the following reasons:

Creating a texture for the compositor seems hard - the only way I could find to do it was switching off Cycles and into BI, creating a new texture, and then switching back.
When using a Blend texture in the defocus node, it seems very hard not to get a sharp 'edge' where the blur 'turns on'.
Most confusingly, it seems impossible to rotate a texture in the compositor. In the node editor for a material, this is trivial, but I can't see how to do it here.

Any advice regarding the above confusion, or on a better way to achieve my goal, would be greatly appreciated.
Thanks.

Use a mask instead ;-)

To rotate, connect the texure to a rotate or transform node

@sambler Both of those methods end up clipping the texture to the dimensions of the image. Again, this is different to behaviour for material node. See here: https://imgur.com/a/2FINzvG

Instead of using a gradient you can build a mask really quickly. Use the shift drag function to extrude a feathered edge from the shape. Invert the color of the mask using the little invert icon in the mask window.

Thank you. I will give that a try. It would (as always) be nice if there was a procedural way to do this.

Well you can use the distort>lens distortion node, leave it in white, you'll get a fitted circle (circle edges touch all sides of the pros dimensions). Then apply a blur.

Well you can use the distort>lens distortion node, leave it in white, you'll get a fitted circle (circle edges touch all sides of the pros dimensions). Then apply a blur.

Or for a perfect circle use a Bokeh Shape node with Rounding turned up to 1.000. Add a Scale node set to Fit, then blur or use Dilate/erode node set to feather

And you can make variations of gradients using the texture Marble (in cycles or Blender internal), here I have made a rectangle that you can scale with the Less Than node.

Using this basic Marble texture

As far as rotating a texture in the compositor goes, you can use the "Rotated Texture" node group from this file:

Explanation here: https://blender.stackexchange.com/a/131433/68997.


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Camera Data "View Vector" Interpretation
I am trying to develop some materials with interesting optical properties. In doing so, I am investigating the use of the "View Vector", however I do not understand it. Looking at the documentation, it says it is a (unit) vector pointing from the camera to the point on the object.
However, the following screenshot suggests something different. I would expect taking the dot product of the "View Vector" with the object normals should yield a value of 1 when the object surface faces the camera, and a value less than 1 elsewhere, specifically zero for parts of the object perpendicular to the camera viewpoint.
The 3 objects in the screenshot show a) behaviour different to that expected and b) seemingly inconsistent behaviour. What is going on here?
Thanks

The View Vector is in Camera space, but the Normal is in World space.
You need to transform one of the vectors to the other space if you need to compare them. I learned this now so I mark this question as helpful.

But this can apparently be simplified using the Incoming socket on the Geometry node. Incoming points towards the camera instead of from Camera towards geometry so the Absolute math node becomes redundant.

Perfect, thank you! Marked as correct. Can't mark as useful due to rep.

As a follow up, it seems that the 'Incoming' output from the Geometry node is a good replacement for 'View Vector', and does not require the Vector Transform node. Any comments on the difference between these two would be appreciated!

Good finding! I have updated the answer.

And just to confuse everything, if you ever use OSL, its I global variable points the other way from Geometry's 'Incoming'


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Min/max values of attribute in geometry nodes
Is there a way to find the minimum and maximum values of a particular geometry node attribute?
As an example, let's say I have a bunch of points which have had a number of manipulations performed on them, which have some randomness included. I would then like to modify the 'z' position of these points according to their distance from the origin, 'd'. In particular, I would like to apply the following maths:
z = a*((d - d_min)/(d_max - d_min))^2

where 'a' is some input value, 'd' is the distance from the origin, which I can easily calculate, and 'd_min' and 'd_max' are the minimum and maximum values of 'd', respectively, which I don't know how to obtain.
It seems like this really should be easy to do - I can look through the spreadsheet at all the values of 'd' after all...

so you mean e.g. like the maximum z-position of ALL points?

I think it's not that straightforward to get these values, like in the shader editor each individual geometry piece isn't really aware of its surroundings, apart from vertices and edges which belong the same face. There is a Bounding Box node that should cover the min and max enveloppe points of the mesh

@Chris: yes that's right.

@Gorgious: I agree a similar problem exists in the shader editor, but there seems to be a relevant difference in that you often need to render in order to get the properties you care about, but you often want them before you render. Here though, the geometry is generated before render item. In my specific example I was thinking of point instances, but I think it's equally valid to think of mesh vertices. Either way, all the info is available to Blender since one can simply read it in the spreadsheet editor - it would just require Blender to read those values and find the min/max.

feel free to upvote this rightclickselect request : https://blender.community/c/rightclickselect/wKvz/?sorting=hot

I would hope a better way is introduced latter, but for now:

Assign the attribute to the position x value
Get the bounding box
Seperate out the x max/min
Merge the value back into the original geometry

Perfect, thank you. Agree: a more elegant solution from the devs would be great!

The main limitation of this method is that you can't return outputs for grouped IDs like you can with the Accumulate Field node. This proposal I made could address that if implemented : https://blender.community/c/rightclickselect/wKvz/

The Attribute Statistic Node can easily do this, along with other useful metrics. It's in 4.0+, but I think it was introduced sometime in 2023.


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Hair particle orientation flips when responding to wind
I am trying to set up a scene with grass modelled as a hair particle system which responds to a wind field. The grass moves in the wind just fine, but as the strength of the wind changes from positive to negative, the orientation of the grass objects flips.
Here is the orientation with a positive wind strength:

Here is the orientation with a negative wind strength:

As the sign of the strength changes, the hairs seem to instantaneously rotate 180 degrees about z.
Here is an example .blend file: link
The problem seems to be that the orientation of the hair is controlled by the wind - rotating the wind about z clearly shows this. Note, that the 'affect rotation' setting is unchecked in this example:

Any help greatly appreciated!

Honestly, I don't know why this flipping happens. But you can use the Particle Instance modifier instead of the Rendered as Object method. The advantage is that the grass does not flip and it can bend in the direction of the wind (and not to the left or right).
To use the Particle Instance modifier method to the following:

in the Particle Settings of the Grass (plane) reset the Render > Render As value to Path
select the grass blade (Plane.003), and move it to the world origin with Shift+S & Selection to Cursor (make sure the 3D Cursor is at world origin like in the uploaded blend file)
in Edit mode, straighten the grass blade. Then in Object mode, apply the Scale to the object with Ctrlt+A & Scale. Just to note, it's important that Scale, Rotation and Location are applied and object's origin is at world origin. This should be now the case:

add a Particle Instance modifier, move it up before the Solidify modifer, and select the Grass (plane) object + ParticleSystem and tick the [X] Create Along Path checkbox:

The result should look like this:

Now the grass bends in the right direction and does no longer flip direction but it twitches in the wind when the animation runs. To get rid of this behavior and to add more realism you can enable [X] Hair Dynamics in the Particle Settings of the Grass plane and adjust a few settings:

set Hair Dynamics > Structure > Vertex Mass to 0.1 kg. This influences the inertia
set Hair Dynamics > Structure > Stiffness to 2.500
and reset Field Weights > Wind to 1.000 so the wind has full influence again.
if the grass blade looks blocky then increase the Viewport Display > Strand Steps. There is also an equivalent setting for the render (Render > Path > Steps).

Final result:

Variations
The Particle Instance modifier lets you randomize the rotation, and size. The two Layers which are vertex colors can be used in the material shader to change to color or texture mapping.
For a completely different geometry, you need to create a new model and add another particle system. Unfortunately, it is not possible to specify a collection with multiple objects as in the Render As method.

Perfect, thank you very much. Is it possible to instance a collection, as one can when using a particle system directly ('render as collection')?

That's a good point. Unfortunately, it's not possible to instance a collection (or at least I don't know ;-) If you want to add flowers for example you need another particle system, weight paint if you like, and a flower model. But the color, texture, size, and rotation can be randomized. I've added this info to the answer above.


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Is there a secret setting that keeps me from painting textures
I am sorry if there is already a post like this but the only things I've seen are tutorials and explanations on how to set-up the start file or something similar for texture painting.
My problem is that i can't bring it to work no matter what. I've made sure that I am on the right paint slot, UV-Map and object. It all doesn't work. The weird thing is that this only occurs on my project so I believe there is a hidden setting or something that I must've clicked by accident that keeps me from progressing further. Is there a way to reset only the project settings? Without messing with my global preferences?
I have uploaded a video on Youtube which shows what I mean.
Youtube Video

You could just take a screenshot of your 3d viewport with Toolshelf opened when in Texture paint mode. In general this is most likely the problem with brush settings. In this case, set the Blend mode to e.g. Mix instead of Color, second, get rid of the (probably) empty texture in the texture mask settings (Texture rollout).

Ok. Nice! I had it set to color. Thanks for the hint.

It was a really simple solution - change Blend mode of the brush to Add (in this case) instead of Color and remove texture mask with empty texture from the Texture rollout.


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xnormal weird normal map bake, substance and handplane baked flawlessly

can someone possibly explain why this is happening, this was from a model I baked in XNormal, I don't really understand why its having this effect. I tested bakes in Substance and HandPlane; both gave me okay results. While XNormal gave me this. If only I knew what caused this it'd be easier to fix.
I recently found a forum post about it, but no real answers were given.
I checked my smoothing groups and my cage; it was perfect or okay. Given that it baked perfectly in Substance and HandPlane It should of worked in XNormal. Previously a similar effect appeared in substance yet XNormal baked it perfectly.
The effect is random to me and I have no Idea what causes it. Could any of you shed some light on this?
Thank you, in advance.

I found that .OBJ have less problems than .FBX when it came to XNormal bakes, so I opted out for OBJ to FBX convertion on final output.

In Xnormals for the Low poly select average normals, also when importing mesh into engine recalculate normals.. this will fix your problem.
Still got to figure out how to export clean normals with blender fbx :D


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Why when importing blender file .blend to unity3d it's not importing all the models/objects?
In the screenshot you can see that in the unity3d when i click on the parent object i see all the models/objects but most of them in orange and only some of them in red.
If i will not select the the parent object all the orange will not be show at all(second screenshot) only the red. And i checked the inspector of the red ones and the orange ones and both have same scale same material but for some reason after importing it from blender i can't see as objects in unity3d most of the models.
I have blender version 2.78 and i did in blender File > Save As and saved it as blender file. Then in unity in my project directory i coped the blender file to the Assets directory then dragged the blender file to the Hierarchy.

And

Not sure if the problem is in unity or with the blender, seems like in blender even that in blender i see all the models in red only in unity most of them orange/empty. I tried also in blender later to make File > Export > FBX (.fbx) but then when copying to the unity assets directory i get the same result as before.

At first glance it looks like inverted normals. Have you tried swapping their directions?

Yep looks like a normals issue. It also looks more like a question about Unity then Blender itself, probably better ask at the Unity community instead.


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Why can't I get the camera view like in the tutorial?
In this tutorial: Create a Realistic City - Blender Tutorial
At 10:36 he presses CtrlAltNumpad 0
When I do the same I get nothing but an empty view.
Then he goes back to object mode and can play with the camera zoom in out.
I'm now in edit mode and everything selected.

And more or less I'm in same position as he is.
Now when I press CtrlAltNumpad 0 I get this:

Not even close to what he did.

This is the tutorial: https://www.youtube.com/watch?v=i4ySFm4ey9U&t=328s at minute 10:55 you can see the view he is in and it's nothing like what i'm getting.

@testman tm the clipping value you have is the same he uses in the video, but the clipping values are always relative to the scale of your scene/objects, so you maybe you have different scaling, and so you need to adjust them to fit your specific scene.

The clipping distance for the camera is probably too short. With the Camera selected, go to the Camera tab and adjust the End parameter to something more appropriate for the scale of the scene.

After you've done that, you can play with the position, focal length, and sensor size to get the look you're going for.


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Why is Ctrl + J not doing anything?
I'm trying to follow this tutorial: Create a Realistic City - Blender Tutorial
At timestamp 6:38, he selected all of the objects (using A) then joined them together using Ctrl+J. However, when I use Ctrl+J, nothing seems to happen.
I am using Blender v2.78

make sure you have no, non mesh objects selected, you can't merge lamps or cameras, I'd suggest deleting anything that's not a mesh.

Also, you need an active object for join to work.  The active object is the last object you selected and has a brighter outline than the other selected objects.  If you just deleted an object its possible there was no active object when you did Ctrl+J.

You need an active object to enable joining - indicated by the object being slightly lighter than the other objects. Shift select one of the object and try again.

@ Firewill - it doesn't matter if you have other objects selected - even cameras and lamps - as Blender will just ignore them. As long as some of the objects are meshes and one mesh is active, joining will work for the mesh objects.

i noticed there is a bug in blender that sometimes CTRL+J will not join the objects. i have verified this.

When your mouse cursor is hovering the 3D Viewport, it'll work.But in other layers or areas, CTRL+J won't work.

You may have a different keybinding set for this shortcut. To make sure you're using the right one, navigate to the following:
File > User Preferences

Input > Enter join in the search bar > Under Object Mode, read the keybind.
As you can see here, my keybind for join is set to J
If you want to change it back to default, click Restore. Make sure to hit Save User Settings before exiting.

If you're changing the keybind to a completely different setting, make sure no other functions have that same keybind.

This can be a solution in GUI:
Step one: make sure the ojects that you want to join are of the same type, i.e. all are meshes.
Step two: select the first object.
Step three: select the second object.
Step four: click 'Join' button shown in the screenshot here (yellow arrow)

This solution worked for me:

Select the 1st mesh in a collection.
Then SHIFT select the last mesh in the collection.
Then finally do CTRL+J while still selecting them.

Use Ctrl + J just at the beginning. When you import the city, press A then press Ctrl + J. It worked for me, hope it works for you, too.


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Why when clicking on numpad_0 or only 0 i don't see anything with the camera?
The camera is viewing the city.
I scaled the camera made it bigger.

Then i click on numpad_0 and see

But if i will make a new project with only the cube in the start and will click the numpad_0 it will lock and show the cube.
Why it's not showing the city ?

Scaling the camera object has no effect whatsoever, other than its visible size in the viewport.

This is due to your far clip setting under: Camera Tab -> Lens -> Clipping -> Far.
Adjust that to a ludicrous number and you should see your buildings, but I'd suggest adjusting your scenes scale since this gigantic scale may cause other problems down the lane.


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does AVI RAW suppport sound in Blender?
when I render my Blender Video Editor projects to AVI RAW, I don't get any sound in the output file.  I'm on version 2.78.5.

Then probably not. Why not use a more modern video container like Matroska (mkv)?

Go to File Format and choose FFmpeg vid – this opens the proper encoding options.

Or choose Xvid and avi file extention.


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The preview windows in the Blender VSE does not have sound and a blank screen
First of all, I know this has been asked before, however, none of the answers from those post fixed my issue.  So I need this answered, so please respond and don't flag this.
When I preview my project in the Blender VSE, there is no sound or video.  The files are still where the path is.  What should I do.  I opened it a few times and it always does this.

The file is sitting in the PC\Downloads folder alright but from here it looks like the VSE is looking for it in another folder.   When you can't see it in the preview window and you appear to have that activated, it's usually because the VSE can't see the file where it's looking.   Select the video strip, press N and goto the source folder icon and change the path and file to the PC\downloads\ etc, see how that goes.


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I only get four video output options
Even when I start a brand new file in Blender, I only get four video output file options:
AVI raw, AVI JPEG, Frame Server, FFMpeg Video.  I am running version 2.78.5 (I'm using the beta so that I can use denoising.
How can I get access to all the other video outputs other people have? Like this:

other video formats, other people have other formats like mp4.

for example something like this:

https://i.sstatic.net/wp9Yd.png

i had the same issue but now i can't set the output to rgba.

@KingDynamite screenshot?


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Edit Mode Snap Problem
My English is nad. I am sorry. Blender dont snap in edit mode selected mesh. But snap other objects. Please help me.
https://streamable.com/q98hp

You have to enable "snap to self"


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How do I combine/join/merge all vertices at the same location?
So I imported this *.obj model file. It is a mesh that has all the faces exploded/split/whatever, meaning that the thing is a collection of separate polygons that are not connected to each other. There's hundreds of them. So I selected all the vertices with A and tried to merge them with Alt+M, which of course deleted the whole model, because it merged all the vertices into one. So at the location of each polygon corner can be up to six vertices, each belonging to a different face that are directly adjacent to each other, yet not connected to each other. Is there some sort of a smart functionality in Blender that recognizes duplicate (or more) vertices at same location and merges them?
I am quite a n00b at this, so please forgive me for not having the best grasp on the correct terminology.

You are looking for remove doubles. It can be found in the 3D view tool shelf while in edit mode.

The hotkey for this is Ctrl+V -> Remove Doubles


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Lightning by HDRI is wrong
Scene was made with Daz3D, but I'm sure that lightning will work the same way in any 3D-rendering program.
1-st render is made with all the meshes:

2-nd render was made only with object on the floor and HDRI background of the same room(spherical camera setting was used to render seven frames with different exposures and glue it together into HDRI-image with Photoshop. I used 7 exposure values: 1/15,30,50,125,250,500,1000)
As you can see there is something wrong with lighting(object on the floor is lighted very differently)
I'm looking for the cause of this issue, but lacking experience in HDRI-lightning.
P.S. Another angle in the same scene and all objects are present:

Another angle in the same scene with only HDRI background and prop on the floor is used as mesh:

Looks to me like the image you are using as environment is not using scene referred values, but has been transformed to display referred ones. I would not trust photoshop to do an HDR image correctly, but I don't use that app anyway. Please describe what format you are using to export the images used to create your "HDRI" A tonemaped image is not the same as a high dynamic range image. If you create the image using OpenEXR instead of other formats for your environment image you will preserve your data as linear scene referred.

Thank You for the answer

Image format I was using is "File Type: Radiance (.HDR;.RGBE;*.XYZE)


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Blender auto-morphs like Daz3D?
I have one small question that I'am unable to formulate correctly to find an answer.
In Daz3D there is some morph-system or something that automatically adjusts unrealistic bending of mesh in required spots while moving/rotating bones in viewport.
Pictured explanations attached:

Question is: are there any similar scripts/addons/something that can replicate such behavour in Blender?

"Preserve Volume"? https://blender.stackexchange.com/a/237245/2214

You can additionally try to add a Smooth Corrective modifier after the Armature modifier, this might help a little as well.


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All in one node setup for most texture map types?
Is there a node setup that anybody may show that will allow you to easily put in most texture maps in one simple set up. For example something like Andrew Prices PBR material nodes. But instead have options that will say the texture maps of color, gloss, AO, spec, depth, bump, normal etc. and then by puting only the texture maps you put in (through image texture node) and will produce your output with what you have put and the empty sockets will be ignored and the sockets you have used have a slider.
If nothing like that exists or it will be very dificult to build, what is the general node stup so that if I have all of these maps (or most of them if not all).
I believe that this question only shows only a few of the maps:
How do you apply a gloss and spec map on one cycles material?

Well I wanted to see something specificly for them. I love the Lord of the Rings speech!

Well if I was to use the pricipled shader, where would each map go?

How do you add a depth map?


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Use position data of one geometry object on another
I am using Curve to Mesh to apply a profile along a circle. The profile curve is a line. I want to vary the length of the line according to e.g. the x coordinate within the circle. There are various vector math and math nodes that allow me to manipulate a 'position' input, but I do not know how to get the correct data flow. In the node setup shown in the picture, the 'position' input corresponds to whatever geometry I end up connecting it to, but a) I want to use the position data of one piece of geometry on another geometry, b) the input to 'curve line -> end' is not a field.
Any advice greatly appreciated.

I am not sure what you want to achieve, but if you want this:

you can use this node setup:

Be aware: There is a big difference between circle sockets and diamond shaped sockets. The circle sockets are single value only. They are constant over one frame. The diamond sockets are fields (aka multiple values). So you cannot do it as you did want to do it. You have to change the position of the lines after instancing.

Sometimes, it may be convenient to manipulate the Radius of the path curve, down which the profile is swept. That gives you a (XYZ) uniform scale of the profile, which can be varied as some function of the path:

nice one!! love it


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Particle Object to Inherit Uniform Colour from Emitter
I have a particle system which is rendering as objects. I would like each of these objects to have a uniform colour. I would like the colour to be dictated by the underlying material of the emitter. I.e. if the particle is emitted from a red part of the emitter, it should be red all over, if it's emitted from a blue part, blue all over.
I thought that this question would solve the problem for me:
Particle Color based on where the particle is emitted?
but it does not seem to. Here is my simple MWE .blend:
https://bit.ly/3bFLLcC
and below is a screenshot:

Any help greatly appreciated.
Thanks

Switch from Eevee to Cycles, make the materials Single User Materials by clicking on the "2" right to the material name in the material tab (either the plane or Suzanne) and uncheck "From Instancer" in the "Texture Coordinate" node of the plane's material node tree (only your instanced object has to have this option checked). If you change the noise texture setting on your plane, copy the plane material to Suzanne where you have to make it Single User and check "from Instancer":

Thank you very much. That works. I swear I tried this before and it didn't work! My MWE was left on Eevee not cycles by mistake.
However the behaviour changes if I change emission from 'faces' to 'verts' - the particles all turn the same colour.
Also if I change it to 'grid' rather than 'random', the same thing happens.
Finally, if I switch from 'verts' to 'volume' then to 'faces', it does not update the appearance. This lack of updating with particle systems is something I have seen frequently.
Are you able to reproduce this behaviour and do you have suggestions?
Thanks again

@d401tq
Theory:
Since the setup above is based on UV-textures which are projected from the 2-dimensional UV-texture space onto surfaces it's logic that the emission source has to be a face.
For the 3-dimensional procedural textures using UV-coordinates like the "Noise" texture in our example here, only the color values at W = 0  are taken into account (Note: "W" is the third dimension in a UVW-texture space but Blender's UV-editor only uses the UV-plane at W=0) .
The only colors associated directly with vertices are vertex colors which you can access by an "Attribute" node in your "Shader Node Editor". Use the name of your vertex color map in order to specify that attribute. By this you can use vertex colors for shading objects in your rendering but only on the object that has these vertex colors. You can't access vertex colors from another object so that your instanced object can't copy the vertex colors of your instancing particle emitter object.
Grids are totally separated from the mesh itself so that they can't have any connections to UV coordinates onto which the mesh vertices are mapped in the process of UV-unwrapping.
Solution:
If your object instances don't need one color per instance at maximum but can copy the emitter object's surface color rather like a chameleon then try it with object coordinates and choose the particle emitter as the source for theses coordinates. Furthermore set the noise textures on the instancer as well as on the instanced object to "2D" (a 2-dimensional noise texture beeing stretched along local Z):

This works as long as the object instances don't move away from the particle emitter or - if they move - only along the emitter plane's local Z-axis:

This is my node setup:

Very clear explanation, thank you.

Please, oh please, could you show me the node setup for that amazing chameleon-effect? Or explain like I'm incredibly stupid?
I desperately need to make scales on a snake (my question https://blender.stackexchange.com/questions/195362/particle-objects-copy-emitters-color) but even with your explanation I can't figure it out.
Thanks!

@CBarr I've seen your question which refers to a tube like body. My example above only works with a plane since it uses the object's local z axis. But fortunately user "unwave" has given you an answer  with a pretty cool looking screenshot already yesterday.


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Offer animation - Blender or some other program
I know this question is not directly related to Blender but I don't know where else to ask it.
I am working in a small company which should make a presentation of an assembly line that we have constructed in 2D and 3D CAD software.
The presentation should look something like the ones from the next links
https://www.youtube.com/watch?v=9fpdeLxUBPk
https://www.youtube.com/watch?v=oFEQJBHdn0U
1) Is Blender good enough to make something like this?
I should present line to non-technical educated people so I only need to show them concept instead of details.
2) I am thinking of hiring someone from UpWork community or similar sites (I don't have time to learn modeling in Blender), do you have a better idea?
Best regards!

This is indeed considered offtopic here, https://blenderartists.org would be a better place to ask. There is even a section for paid work if you consider hiring. There is also https://www.blendernetwork.org for hired work. In anyway Blender seems more than capable and an adequate tool for that type of work, depending on the skills of the artist and available time you may easily achieve better quality.

I'm voting to close this question as off-topic because it seems to be about hired work

Wanted to answer in comment, but, seems would be better to answer directly.

Blender is more than good enough for this.
a) You have to decide if you want an interactive or a video.
b) You have various options for costing, if that is the issue! You requirement seems quite possible for interactivity
c) You can also have basic interactivity with a number of videos and have a web based application.
If you plan to hire, Blender or any other tool should not matter (it depends on the tools used by the one whom you have hired. But please support blender :))
For 3d interactivity you have options on web and/or app, there are technologies and engines for webgl (blender2web,threeD.js) and for apps Unity3d, UE4 and more.
I'll recomend App over Web for 3d.
Make sure you have more than cad drawings for the person developing this, a video of the process would be more useful than cad design and text.
You can try various forums as Blender forums, Unity forum, Ue4 for people and teams who provide you with 3d services. Do understand if its onetime work or something you want further development.

Thank you for the detailed answer. No.5 could be a problem since this should be a video for a project demonstration so we can get a contract. I have little assemblies produced so I can test critical spots, but I cannot produce without customer funding.

Some reference, even if its loosely related would help. Also cad can be annotated to be more artist readable :) . But either way, all these only help out, but not a necessary requirement, so things would workout even without  references.

Blender is good for this type of presentations.
You can make video like this:
https://www.youtube.com/watch?v=L__2suWPk9s
or interactive 3D-presentations like this (using addon blend4web): https://www.blend4web.com/apps/dairy_plant/dairy_plant.html?v=9e5dd2c40ed17b48ebd949bf7f8d9d0c

Thank you for fast reply.
I love both representations, but I think the second one is out of my budget.
How long would take someone to build animation like first video?
Best regards!

@TomislavHorvat I've made it in one day


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Squeezing shape by another one
I'm trying to simulate the growth of a cancer in the blood vessels in Blender 2.78c. Firstly, I created the network of blood vessels using this addon. Then, I created a simulation of the cancer with the UV Sphere growing in time (using keyframes on the Scale property). The problem is that this growing ball penetrates through the blood vessels, while I want to simulate the collision between the growing cancer and the blood vessels, which results in something like squeezing these vessels.
After some research I think that the blood vessels should be modified by the Soft Body, while the growing sphere should be modified by the Collision, but I'm still not able to simulate the collision between these two objects.
Here is my blendfile without any Physics. Thank you for your time.

If the goal is to show the blood vessels change position with the growth of the cancer, this answer might be useful - https://blender.stackexchange.com/questions/70151/how-to-animate-a-beating-heart

This is not at all a "physically accurate" simulation by any stretch, but it may be able to approximate the desired effect with a bunch of modifier trickery using a Vertex Weight Proximity and a Cast modifier.

Use the Vertex Weight Proximity to make a vertex group weight vary according to the distance to a random object, in this case a "cancer ball", then use said vertex group to drive the influence of a Cast modifier set to Sphere.
You can then dynamically adjust the size of the "cancer sphere" (and shape too) to influence the distortion of the blood vessels

That's enough for my needs. Thank you very much for the detailed tutorial.

You can use a Lattice to deform the mesh. Otherwise you could try parenting the mesh to an object then deforming the parent.


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How do you make grouped objects a focus point without moving the camera?
In my blend, I am trying to focus on a pile of doughnuts and then focus on them. While doing this, blurring the background and the side windows without losing some of the detail on them but making them quite blurred. How would I do this? I Have tried making an object a focus but it is not achieving my desired finish. This is a sort of blur I am looking for...

I will atatch my .blend file if you would like to see.

This is generally done in post production in the Compositor with nodes. Can also be done directly in the 3D view but it is computationally more expensive.


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How does CPU and GPU work? Which one is better? What are each of those best settings?
I've heard many people talk about that there being CPU and GPU but I have always wondered how do they work and if you are using one more than the other what are the best settings to keep (assuming that you are rendering an image with a lot of reflection, D.O.F etc.)? What actually happens inside your computer?

I'm voting to close this question as off-topic because it is not about Blender

@DuarteFarrajotaRamos - While I can see your point, when I originally read the question, it seemed to me he's speaking in relation to Blender and how CPU and GPU rendering differ.

As of today, according to the Manual, the only significant difference in features is the ability to use OSL in CPU mode.  OSL allows you to create custom shaders.  Other than that, there should be little if any difference in the output of CPU and GPU renders although you may have different noise patterns.

Of course, then there's the speed difference.  For the price, GPUs are more cost effective for faster rendering (although a recent spike in price caused by lack of availablilty due to the Ethereum craze has made that less so).  Even though certain processors like AMD's new Ryzen 16-thread processors can be faster than some decent video cards, they are also expensive, and you can only have one in your computer at a time.
With GPUs you can have up to four in typical consumer motherboards.  I have three different GPUs running in my rig at the moment.  They are all nVidia Cuda-based but they're three different model based on budget.  They can absolutely slaughter my i7-6700k (8-thread) at 4.4GHz.  This is because GPU's are really good at parallel processing.  My CPU has 4 cores (2 threads per core) but my video cards have over a thousand each.  3D Rendering happens to be a really good mathematical scenario for mass parallel processing.
Consider this scene rendered at 1200x900 with 500 samples:

The ($340) CPU rendered it in 7:02 but the three GPUs rendered it in 1:51.   This does require tweaking the tile size settings though.  There is a lot of poor or anecdotal suppositions out there about tile size and nobody seems to really understand why or what to set it to.  Keeping the tile size to a certain multiplied number yields the fastest render times.
For GPU's the tile size typically needs to be a X and a Y number that multiplies out to 65,536 (256x256).  I have a 128-bit card with 768 Cuda cores, a 256-bit card with 1664 cores, and a 256-bit newer architecture card with 1280 cores.  They all perform most efficiently with a 65,536 tile size.  I don't know why and I have yet to find anyone who can explain why.
But the ratio of the tile size will vary based on the ratio of your render.  You want the tiles divided such that there are no "fraction-tiles".  What I mean is that you should have a whole number of tiles.  For instance, with 1920x1080 renders, I choose 240x270 tile size.
This yields exactly 32 equal tiles and 240 x 270 = 64,800.  This is the most efficient GPU render of a 1080p scene:

For CPU's you can set it to 16x16 or 32x32 and forget about it.  There's no reason to try to calculate it for each render ratio because the differences are so small.
Another consideration is scene size... memory.  With the CPU, the scene is stored in system RAM.  This kind of memory is cheap and you probably have 16 or 32GB of it.  With GPU rendering, you use the memory on the video card.  Video memory is more expensive so you typically don't have as much of it.  My most expensive card has 6GB.  You are limited in your Blender scene to the least amount of memory that one of your cards has.  My lowest end card has 4GB, so if I want to use all three GPUs to render a scene, that scene must require less than 4GB of video memory.
Let me know if you have a specific question that I haven't addressed.


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understanding uv maps, materials and textures
I have made a very basic room. I am trying to make game assets for using in Unity.
In the past Ive made some uv maps but I remember struggling, and this is actually more of a complex shape that I had before.
For now I just want to assign a texture to the wall (I'm happy assigning the texture in Unity if thats easier, I dont need to render anything in Blender)
I've drawn a 'Seam' around one wall. Also, earlier than that I have selected every face on the wall and assigned a second material to it.
(Note: I already imported it to Unity and the two materials appear there, but when I assign a texture as the material it just comes out as a solid colour.)
Is it correct that I can mark a square seam as pictured, and then assign a texture to it? And if so how do I do this, is there any simple tutorials just showing this? Thanks

You have to add a texture to the material in the texture tab next to materials. Then select the mesh you want textured and bring up UV/Image Editor. To select the texture in UV/Image Editor you have to click the little picture button to bring up the drop down menu and then select the texture from there, while in edit mode, while the mesh you want textured is selected (not the object).
It's a little weird at first.

I think this answer could do with some images to show the process you're describing.

thanks guys. I think i follow the instructions but I am currently working on something else, so cannot try this yet. As I say I, I have managed this in the past after some trouble, but have forgotten some of the steps. I think you have explained well enough for me to do it now. And if poss, I'll take some snapshots to show others how its done and post here later


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Blender and Unity. Materials/Shaders question (Cycles, BlenderRender, Does it matter??)
I have been tinkering with Unity and Blender for a fair amount of time, although mostly in Unity I don't have much 3d skills in Blender yet.
But I'm struggling to fully understand materials.
If I assign materials to areas of the mesh in Blender. (Let's say I am making a basic house. And I assign a material to each face (walls) and then a couple of windows with a separate material. Do I need to tinker with the material settings inside Blender?
I wonder this because I have been making materials in Unity for a long time, and I could easily change the materials there. But when I watch/read Blender tutorials they always make lots of changes in the material. I wonder is this because they want it to look nice in a Cycles render or whatever, or because it is needed to become a game asset.
So imagine my house in Blender is all white (like the basic Blender mesh material colour). And I just have the material1 and material2 (mat2 where the windows go), can I then import that to Unity and just set my own materials from there for transparency etc?
Anyone experienced with importing their own Blender stuff specifically for Unity use and not rendering inside Blender, please let me know your workflow for simple 3d models to Unity (with more than one material/texture)
Note: I also do use UV mapping. And it works great, but I haven't yet done one with transparent windows using UV mapping and this got me thinking that I don't need to mess with the materials/shaders in Blender.
Cheers ! :D

https://blender.stackexchange.com/questions/57531/fbx-export-why-there-are-no-materials-or-textures/

Check out Poliigon for amazing textures if you don't want to tinker the settings manually.
In Blender, we mostly use Cycles Render engine and starting 2.80, the internal render engine(Blender Render) has been removed.
In order to tinker with the material settings, you need to make sure the render engine is set to Cycles render and select Node editor from the bottom left corner(change from 3d view to Node editor or extend a new tab and change it).
It works similar to how 3d View works, shift + a to add a new shader,x to delete, g to move etc..


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materials.alpha not working
Not seeing anything different on the screen when setting the alpha property.
Any clues?
def color(name, diffuse, specular, alpha):
    mat = bpy.data.materials.new(name)
    mat.diffuse_color = diffuse
    mat.diffuse_intensity = 1.0
    mat.specular_color = specular
    mat.alpha = alpha
    bpy.context.object.active_material = mat

act.color('Red', (1,0,0), (1,1,1), 1)
# tried 0.5, 0.25, 0.001 etc..

Are you using cycles?

i wanna say no, but not sure what that is. dont see cycles in the code. (new to bpy)

This solved my issue:
    mat.transparency_method = 'Z_TRANSPARENCY'
    # need the following 2 lines for alpha to work
    mat.use_transparency = True
    bpy.context.object.show_transparent = True


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How to switch between Bake and Material view quickly?
How can I switch between a new material I created with a texture bake and the three original materials in one object in Blender, without needing to manually reassign the materials? I want to be able to preview the material with bake and then switch back to the original three materials simply without needing to delete them or use 'Ctrl+Z' to undo the assignments. Is there a more efficient way to perform this switch? Without also needing to clone the object.


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How to remove these black areas of Bake?
Is there any way to hide these areas at the time of Bake?

Black appears where geometry intersects/overlap. I am wondering, will Mask modifier or Boolean subtract will do the job while baking?

I understand how it works, but is not there a way to hide or remove this area during the bake? I do not know how to use these modifiers.


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Model great, but mesh is very weird!
I do not know how to explain what is happening, I imported a model that I had saved some time ago. But it is with the mesh in a very strange way.
I already checked play for a new project, normals, remove doubles, decimate, merge vertex loose, but nothing solves!

Try to Remove Doubles in Edit Mode. Select All > W > Remove Doubles.

Check the clipping values for the viewport. See https://blender.stackexchange.com/questions/1385/shadows-along-edges-of-mesh-in-3d-view

Changing Clip value solved my problem!
The models were very large, I needed to increase the clips to view the models without limitations of view, but soon after I diminish them and that's where it began to cause problems.


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How to optimize all these objects in 1 Prop to Game?
I'm looking for a way to optimize all the popcorn particles to make a single object optimized to serve as a prop for games. What better method?

Putting together all the popcorns the numbers are absurd for a single Prop:
499 Objects
61,546 Vertices
93,706 Faces
120,836 Tris
NOTE: All popcorn are already optimized to the maximum that I believe do not make them completely ugly or strange.

retopology and normal mapping is your friend here. create a low poly mesh with just the surface of the popcorn layer (with however much detail you polycount allows for) and bake a normal map from your existing mesh.


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How to reduce the glossy noise?
I am using a lamp with shader glossy, without the lamp the scene is good, but when I bring the lamp with the shader increases the amount of noise. what do I do?

You can render less noisy image increasing the render samples, you can also use set clamping to reduce fireflies (very bright pixels, getting brighter with more samples). If you have glossy / metallic surfaces don't set the clamping too low (below 1.5) because it makes the metallic surfaces dull.

In the render window at the right go to the "Light Paths" and set Filter Glossy to 0.5 or 1.
You can also turn off Reflective Caustics but then you wouldnt have any bounce lights.


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Convert beveled curve to rigged mesh
Is there a way to convert a beveled curve into a rigged mesh? I would like to have a rigged rope in a way where the bone weights are calculated from the curve control points, so if I have 2 control points it will be converted into 2 bones, and when I pose them, they will deform the mesh similar to control points?


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Cycles volume render failure
I am trying to render a very straight forward scene in cycles with some volume. I have tried creating a large cube with volume, and I have also added volume to the World. Everything looks great in the preview, and in the render right up to the last noise pass, then poof, the volume disappears. I'm mystified.

Are you using denoising?

Yes - but I have turned it off (both NLM and D-Noise) and on with the same result.


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psa importing error
I export a model from Yu-gi-Oh Wheelie Breakers of WII, then to use into blender I have problem with psa animation
These are the error. I don't know how can I solve them and how con I use these psa animation, please help me!


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Mesh not moving with armature modifier
In a nutshell: I'm working on making some slight changes to the body mesh below and I will be creating some transparent clothes to go on top and the mesh is not moving with the modifier.
I've had this happen before with a top and boots as well, both work in game but I'd love not to have to load my game up to check constantly. I'm using the armature modifier as normal and with some bones I select, the whole object goes purple in weight paint mode and nothing moves with those bones.
With others that work, you can see the bone/vertex group it selects from the list and the weight paint looks normal/the model is blue.
Now with this knee bone as an example, it comes up purple when I select it, but you can see there is weight painting in that area under the 'thigh' group. So why isn't it behaving like it?
Bind to Vertex Groups is checked and Object is set to rig in the modifier.
Pelvis, auto selected when I clicked that bone, working when I move it:

Leg bone, purple mesh, not working. My object doesn't move with it:

Thigh weight paint near that area on my object:

I've had this happen a couple of times and I'm not sure what's up. Makes it difficult to see if things are working pre in game testing. I haven't touched the weight paint, this is just a nude body mesh!
Please ignore the titles of the vertex groups being different, I'm using script to do something unrelated.

sometimes the parenting doesn't work and you have to make some correction, either with in Weight Paint mode or with Vertex Groups assignment

Sometimes when I'm working with armatures, one of the bones wont work. My first thought is if the deform option in the bones tab is unchecked. You could try checking that out.


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BGE Animation problem
I am having a few problems in BGE in relation to animations.

I have a parent and a parented object. When I move the parent in the game, the child objects move fine, but as soon as they have to play an animation, they go to their original parenting place, and play the animation there.
I have a helicopter animation. When the helicopter needs to go faster, it rotates on the y-axis. However, in the game, when I rotate the helicopter, as soon as I play the animation, the helicopter snaps back into the angle it was animated. When I change the action actuator to 'add', when the animation plays, the helicopter flips upside down.

I must apologize, but I do not know how to attach a blend file. If necessary, you can tell me.

https://blend-exchange.giantcowfilms.com there you can upload blend files, use edit to paste the link in your question. also you may want to add somes images of the dope sheet or action editor and more. Have nice day.

Hello and welcome. Please keep only one question per post, ask as many as necessary

I figured It out! When I have to play an animation, I need to change the actuator to add, or local. I think this is it. Thanks!


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How can I separate an entire object by loose parts blender
I have a large house model that is composed of other models. Some of the models in the house for example doors are joined together.

How can I select entire model and separate into loose parts?

that's not going to work, not as a single operation anyway. first you need to select your doors and separate by selection, that will create a separate object of just the doors. then once all the connected objects have been separated in this way, you can then select the main model and separate by loose parts. then you need to edit the door mesh and separate the individual doors by loose parts and so on.


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My Model is not running!
I'm new to Blender 3D, and I'm following one tutorial step by step.
I've edited a free model form internet, made a running animation and, this animation plays fine on time line but something is wrong when I play the script in game engine.
The model is not moving and the arms are spread like wings.
I didn't make any action frame like that.
You can download the .blend file here, and you can see a Youtube video of the problem
I hope somebody can help me.
have a nice day!

Thanks for the youtube video. I believe the problem you are describing is this: Your model moves its arms and legs in a walk cycle, but the model does not move from the center of the grid -- there is no X or Y motion while the animation is run.
If my understanding is right, this is easy to fix: Your walk cycle animation does not include any "forward" motion in the animation. You can add this separate from the walk cycle and make them separately controlled. You could make the legs move faster (by adjusting their scale as an Action Strip, if that is how you have the walk cycle saved) and also adjust the f curve that controls forward motion (if that is what you used).... Again, there are a couple of ways to combine multiple actions...
But I think the essence of your problem is that the walk cycle itself does not include moving the model forward... (I did not download your model, as I do not recognize the download site.)
Shout if I can assist or if I misunderstood.

Really Thanks for your kind answer, regauer. And sorry to late checking your answer. Honestly said, I try to find this question, but I forgot where I wrote this question.(Because Im really new with blender). So I could read asnwer on only youtube. And, I restart from first step and, now it works. But, I still really wanna know the essential reason. You told me about "forward" motion need to be included in walk cycle animation. My character work animation is saved on NLA Editor. But do you mean I need to add my walking animation to another place?

I had 2 problems. freezing animation and diffirient animation on time line and game engine. I found to fix "freezing". Freezing is cleared  : I activate "True trigger" in Logic editor. But still remains problem no2. So I hope to hear your little more advice. Best Regards.


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Moving all files to a new computer, my concern is links
I'm moving all files to a new computer, via an external hard drive.
I am certain that broken links will be a concern. What can I do to fix this? Is there a 'Best Practices' kind of way to prevent this problem beforehand?
I have many hundreds of .blend files, and of course, I fear losing them.

I think the key thing here is to always use relative paths in your blend files when linking external data. That means for linked libraries, textures and any other data external to the file.
Relative paths are mostly guaranteed to work if you maintain the folder structure relative to the blender file intact, even if the absolute paths are changed.
That means if you move your files to a different machine or even on your own current machine but maintain their positions relative to each other things should not break.
Whereas absolute paths are never guaranteed to work in a different machine, unless you can recreate the exact same base path for everything down to the same drive letter.
They are also likely to break in different operating systems, like say you send a file to someone else on a different platform, not even if you change operating systems in the same computer, because for example Windows uses drive letters to locate different volumes, a concept that doesn't exist in Unix based systems, because volumes are mounted to mount points instead.
The good news is I think Blender already does this by default, so in theory you should not have to do anything, unless your store stuff across different drives letters, cross link from network data, or specifically set Blender to use absolute paths.
You can double check this by opening one of the files in question, going to the Outliner and changing the menu in the header to Blender File this should list all local data stored inside the current Blender file, and bellow it towards the end of the list all loaded external data from other .blends. From there you can check which files are loaded and from where.
If a path looks something like //..\Path\to\my\Library.blend or //.\Textures\ then is relative and all is good. If it looks something like D:\Path\to\my\Library.blend (has a drive letter in it) than it is likely to break in the new computer.
You can easily fix this by going File > External Data > Make all paths relative, if all external files are in the same volume as the blend file.
Blender has relatively good asset management capabilities, in the new computer you can then check if anything is missing by going to File > External Data > Report missing files
Now make sure that when you move stuff you maintain the same internal folder structure. One good way to organize your projects would be:
Master Folder
 ├ Blender Projects Folder (for throwaway projects that you may archive at some point when finished)
 │ ├ Project 01
 │ ├ Project 02
 │ ├ Project 03
 │ └ Project ...
 │
 └ Library folder (For reusable assets and library files you may keep around indefinitely)
   ├ Models
   ├ Animations
   ├ Textures
   ├ Materials
   └ ...

Independently of where in the file system you place the Master Folder, if you maintain the underlying internal folder structure intact, and all files reference each other using relative paths within this "garden" all should be fine.
One additional rule I've been enforcing on all my projects for increased resilience besides this, is to make sure each individual project is also fully self-contained and entirely kept inside a single dedicated project folder, with no external dependencies, even in the Libraries folder.
This means making a local private copy of any assets used just for exclusive use of each project at the expense of disk space. This may cost extra storage in the long run, but it means I can safely move each project individually elsewhere without fears of breaking dependencies, like say archiving when finished, or sending to someone else.
This also makes projects resistant to future changes. If you need to open it at a later time, somewhere in the far future, it has been kept safe from any breaking changes (like updates, upgrades, evolutions or other modifications) that might have happened to libraries in the meantime, which could jeopardize the fidelity of the project that has been stagnant.

As said above making a tree hierarchy for your Blender file is always a good idea, but to complement the answer by Duarte Ramos above, packing all your files into the .blend files in the first place
Go to File  > External Data > Pack all into .blend

This would have to be done to all files individually. It will make your files quite portable and safe to move, at the expense of load speed and file size.
Have in mind that not all external data can be packed. Stuff like videos, image sequences and external caches (fluids, simulations, etc) will always remain external.

Thanx so much all, for the tips, but here's the strange miracle: Everything works just fine! I am able to open and work with them, no muss, no fuss. My UV-mapped things all showed up and everything.
I didn't have a master folder before (and was afraid to try and start one), but have been able to fix that, as well – Build a better tree.
Still, for future self-preservation, I'll use these tips going forward.
Thanks again for your help. It's greatly appreciated, especially after hunting for the information, which, as you know, can be a bedeviling experience.

did you copy all the files on your drive (if so then there would be no problem in the first place because the file tree is not disturbed as of to say :) )


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Why cant I see the loop cut line on one side of the mirrored shape
I'm new, so this may sound stupid.
When I make a loop cut, I can see where it is on the original side, but not the mirrored side. Is there some option or setting I need to change in order to fix that?

There are two options to display the result of the modifier in edit mode:

(form the Blender Manual)

Box
Displays the modified geometry in edit mode, as well as the original geometry which you can edit.
Triangle
When enabled, the final modified geometry will be shown in edit mode and can be edited directly.

Enabling the triangle will allow you to "adjust edit cage to modifier result" :

Lemon is right. That option does allow you to view a made loop cut. However, when you are placing it and the pink line appears, you still cannot see the loop cut because the part of the mesh generated by the Mirror modifier does not yet exist. To make it exist, click the Apply button. You will not be able to change the settings any more, however.
The apply button:

Applying the modifier and the changes:

Lemon's notes in my words:
The triangle button allows for the generated portion to be visible in Edit Mode as if the modifier was applied. However, just because it looks like the modifier was applied does not mean it acts like the modifier was applied. Vertices will still be mirrored. Loop cuts will still only be visible in pink on the non-generated portions of the mesh.
The triangle button. Note how the mesh is still mirrored even though you can interact with more vertices. Also note how the pink is still only visible on half the sphere:


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Motion tracking image missing in other computer
I made something in Blender and added motion tracking but, when I move my blender file to other computer, the image that I used in motion tracking disappear in my blender file.
Actually I saved like this: Pack into blender file and Save.
Other external files like texture and so on.. are appear but, the image that I used for background in motion tacking is gone,....
How can I solve this problem?

This is not supported at the moment, reload your files manually (properties panel > reload footage)

As far as I know image sequences and movies are never packed into the blender file. Move them manually along with the file, also consider using relative paths.


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Objects missing in render, light has no effect
I've been test-rendering a character I'm working on and I'm running into some problems. Not only are the eyes of my character not appearing in the render, but light seems to have no effect on objects at all.
In the viewport, all objects are visible and changes in light make changes to the image, but when I hit F12, I get the same thing every time.

[![enter image description here][2]][2]
This is what it looks like when I hit F12

This is what it looks like when I hit F12:
http://i.imgur.com/kjvdfTE.png

Does going out from Local View before rendering fix your problem?

Carlo you nailed it! My last render matched the viewport render at last! I can't believe it was something this simple.

how exactly does local view influence this? thats so weird.

@MadlainaKalunder Local view isolates selected objects from the rest of the scene for closer inspection. As such it also isolates it from the influence of lights and other elements in the scene.

@DuarteFarrajotaRamos but this should be the case only for the lights created with Emission shader; lamps seem to overcome Local view limitation which is also mentioned in the manual in the Note section. That's why the linked answer doesn't really work in that way for me.

Ah yes, it only seems to work for ´pure´ lamp objects. If it is a mesh with emission, o the lamp object is inside a group instance or dupli it will no longer work I think.

Object added in Local view don't update till you go out of it
I never notice, but looks like the object you build while you are in the Local view, despite being added to the outiner, (and so to the scene as well) they don't appear in the Global view till you go out from the local View.
At least this is what happens in 2.78 version.
If you open another window, you can examine the scene that is being rendered:

Eyes are missing, and maybe the planes that are providing light to the scene...all objects that you have probably built while you was in Local view without ever going out.
Those are not rendered because they are in a limbo, trapped in the Local view waiting to be released. That's where the difference cames from.
You can see how the cube added in the image sequence below is not in the Global till I go out from Local view.

I don't kown if this is a feature or a little bug.

If those light sources were added as lamps (Shift+A>Lamp) this won't be an issue as lamps continue light object even if local view is enabled but objects with Emission shader do not. This probably changed as of recent versions as this answer doesn't appear to be the case if using lamps


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Dope Sheet Proportional Edit falloff types?
just wondering if the falloff types are working for proportional editing in the Dope Sheet. All the falloff types seem to be doing the same thing.
I want to play around with taking a batch of keyframes and doing various stretching and squashing of them using various falloff types, including random falloff.
I select the first keyframe in the Dope Sheet, turn on proportional edit, then S for scale and drag mouse right a bit, and I see the stretching out of the remaining keyframes, but all the falloffs seem to produce the same kind of stretching results.
Thanks for any ideas.

Looks like they work correctly if you Grab them around, but not for the Scaling (there's not even any reference about the proportional size in the operator string showing the current parameters).


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How to copy color from webpage to Blender material surface color input value?
Sometimes I see a nice color I like online and I'd like to be able to copy that color to an object in Blender.
I did try Firefox> Tools> Web Developer> Eyedropper to copy hex value,
but upon pasting into Blender material color field the color changes to something completely different than what I copied.
Just wondering if there's an easy way I'm overlooking.
Blender eyedropper only seems to work when clicking something inside Blender.
Thanks for any ideas.

Load an image in Image editor. Use the color picker to sample the color from the image.
All the objects are affected by the light. It will never be the same as sampled because the light and shadows. You have to play with lights and its RGB or HSV values to get close as possible.

Okay thanks for the ideas. So I guess no way other than to actually load an image. I thought maybe a paste of a hex color value but that seems to produce very different color than what I copied from website image, as mentioned above.

You can also load the Image/page here (http://imagecolorpicker.com/) and pick the colour. Then copy the hex-data and paste it in Blender

Thanks, this got me looking more into maybe I was doing something wrong, and it turns out I was. Without checking to carefully I just pasted the hex value into Blender. Turns out in Blender's color hex value field it has to be just the characters without the #. I was pasting it in with the # and it was cutting off the last letter of the hex value. So thanks, this kept me going in the right direction. Works fine now when I properly paste in the 6 character hex value without the #.


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Blender how batch import all the objects from my old .blend projects into a new 'Library" project?
I know about appending, but it's slow and tedious to go one by one to each old Blender project file looking for objects I like.
I wonder if there's an addon, or some known method for pointing to a folder of old .blend files and saying "import all the mesh objects from these old .blend files into this new project"?
Why? Because I make lots of small little studies, interesting shapes, etc, and now I wish to gather them all up into one project, to create a collection of my objects in one place.
Thanks for any ideas.


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Light casts wird shadow on glass!

When I try to make the glass cover for my clock, this is what happens. The strange ball appears to be a shadow that is cast by the light source. When I tick off specular for the light source, the shadow is gone, but the glass is no longer visible. Please help, I'm a beginner and I'm at my wit's end!

Does it actually render like that? It looks more like a transparent hole that shows the grid floor behind it, or is it reflecting the grid floor? You might need to share your blend for someone to find what is happening.

I made the glass all over again and it seems to render ok now. I do not know what was happening before. Thank you for your reply though! It was a project for school, so I'll just wait and see if it got accepted :)


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not able to conect nodes in the compositor
I'm having a weird problem, I've had it before but at the moment I'm using the compositor so much that it's getting really annoying...
at the moment I'm working in 2.82a but I've had this problem in al the versions before that one.
I'm unable to connect nodes by hand (see gif)

I am however able to do it with noderangler, but when I do that the connection starts at another point (see give)

it's also just really hard to select nodes (with a mouse and with my Wacom), sometimes when I click on the nodes or use box select I select the node next to it or just nothing at all. (see gif)

this also makes me unable to use frames because I'm probably dragging nodes "next" to them instead of on top of them...
This all points to the nodes actually being in a different place than they are being shown to me. Do you guys have any ideas on how to fix this?
As is sat I've tried different versions, restarting the program and my laptop and I don't have any other ideas.
thanks in advance

I had the same problem. It looks like having two areas of the interface displaying nodes is causing this bug.
Just close the other nodes area(s) and it should be back to normal. It worked for me !


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Is there a Simplify Curves addon for Blender 2.80?
I'm using the latest Blender 2.80, and I notice a Simplify Curves addon at preferences> addons> search:simplify I see Add Curves:Simplify Curves, but then it says upgrade to 2.8x required.
What is currently the way to simplify a complex animation F-curve?
Sometimes I like to record a complex object movement, but I used to love to then Simplify the curves to various degrees with Simplify Curves addon.
Thanks for any ideas.

Select your keyframes on graph editor.
Press "o" Select SMOOTH KEYS. That should "simplify" a little bit better your curves.
I remember the function "simplify curve" is available for grease pencil, but I don´t remember seeing it elsewhere. Please paste a screen capture.
I hope this works for you. If it does, please vote me up and mark me on the checkbox to the left side of this answer.
Thank you.

Thanks for the smooth keys idea. Yes I have been using that for a while. I do miss  https://archive.blender.org/wiki/index.php/Extensions:2.6/Py/Scripts/Curve/Curve_Simplify/ for the way it would actually remove many of the dense animation keyframes that occur with recording animation. I was just wondering if there's something else like this for Blender 2.80. Thanks again.

Please, if anyone finds a way to make this addon work with 2.8x, reply to me.


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Run VSE movie strip output through Compositor or Compositor movie clip output through VSE within one project possible?
I wish to add a movie clip into Blender then simultaneously use both
VSE and Compositor (nodes) to produce various video effects.
The VSE offers some nice options, and so does the Compositor.
So far, within a single Blender project, I have not been able to figure out how to either
-take the output of the VSE movie strip and then run that output through the Compositor for further processing
or
-take the output from the Compositor movie clip and run that output through the VSE for further processing.
I wish to do this all within one project file.
Is that possible?
Thanks for any ideas.

You can make a separate Compositor Scene that only outputs the compositor result. Then in the VSE scene you can add the Compositor scene as a scene strip.
You can not send the output of the VSE anywhere except for mixdown to codec. Don't worry, everyone asks this at some point.
The VSE is designed to be the end of the production chain.

Okay thanks, that does clarify things for me. I think it's also needed in the compositor scene to uncheck sequencer at properties>post processing. And at VSE scene to uncheck compositor at properties>post processing. Is that correct? Thanks.

Well, with some more testing it looks like I just leave both post processing options checked (enabled) in each scene. Not sure if there's any benefit to disabling either of those two options in any scene.

Yeah they are dependent upon output at the tool. The compositor will be ignored if theres no output node and the VSE will be ignored if there are no strips present.


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how to attach spot lamp to camera and make lamp always face out from camera like headlamp?
still new to Blender and this forum.
I'm wondering how to attach a spot lamp to camera and make lamp always face out from camera like a headlamp? So as the camera moves around, the spot lamp light is always facing straight out from the camera just like a cave explorers lamp on their helmet. So wherever the camera goes, and wherever it points, a nice bright spotlight is shining the way, shining brightly on anything the camera looks at?

You may do it parenting the spot light to the camera or using the child of or copy transforms constraints.

Select the spot light, then the camera and press Ctrl+P-->Object (Keep Transform).

Select the spot light, go to the Constraints header and set the camera as a target.

Note: If you want to go further with the more detailed lighting please see this: How to create a flashlight light May be helpul for you.

@Paul Gonet Thank you very much. And for the very quick response, much appreciated. Yes all three techniques work. I for some reason was trying Track To which didn't do it. Note that is seems I had to do a lot of preparations first, like clearing rotations, cursor to selection, selection to cursor, before any parenting, constraints, etc...for anyone else new to this.

@cegaton Thanks for mentioning to watch out about the the offset. And it got me thinking that offset will come in handy I'm sure at some point when used intentionally.


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Blender VSE_can I make movie strip gradually slow down or gradually speed up?
I'm wondering if Blender VSE can gradually slow down/speed up a movie strip.
At VSE I add> movie strip. Now I want to have the strip
gradually slow down, or gradually speed up.
I am not referring to gradual speed up/slow down of animation here.
That I know how to do.
Thanks for any ideas.

Yes, add a speed effect to the selected movie strip. Turn off the option "Stretch to input strip length", then keyframe the value Speed Factor.

Start with a value of 1.0.
Then move to the next frame that should be normal speed and keyframe
that 1.0 as well.
Go to the frame that should be stretched out, change the Speed
Factor value to a smaller value for slow e.g. 0.5 is half speed, or
a higher value e.g. 2.0 is double speed.
You won't see any effect until you press the Refresh Sequencer button at the bottom of the VSE timeline.

Alternatively if you don't need to ramp the clip's speed you could apply a "Stretch to Length" effect.

Place your play head at the point you want to start slowing down.
Select the Strip and make a hard cut (Shift+K key)
Make another hard cut (Shift+K key) at the end of the region of slow
motion. Select the middle strip and add a Speed Effect, leave it in
"Stretch to input Length" mode.
Move the cut strip up to the channel above and stretch it to the
right length, the speed effect will slow the clip down.
Select the third piece of the clip and move it to the end of the
speed effect, this will continue to play at the original speed.

Brilliant! Thanks so much. Wow. the capabilities of Blender are truly amazing. Your reply helps me get the gradual speedup and gradual slowdown results I was looking for. Amazing really. Thanks again.

I've included an extra version of the speed effect for others that want an easy "non-keyframe" approach. Don't forget that you can also reverse the playback with a negative Speed Factor value.

can that same curve be used to audio? Thanks


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Blender crashes while rendering in GPU but not in CPU
I've just started using Blender a few days ago so far I've made a neat little donut.
https://i.sstatic.net/8QnGt.jpg
I have no problem rendering the scene with CPU but when I choose the GPU Compute setting, Blender crashed by itself.
Here's the user preferences of my Blender 2.78c:

https://i.sstatic.net/sQGpS.jpg My graphics card is AMD Radeon (TM) HD 7450A Graphics.
How do I prevent Blender from crashing while rendering with GPU?
btw I'm using Cycles Render

It's possible that you're running out of GPU memory.  Are you getting any error messages?  Just so you know, depending on what CPU you're using, you might be better off rendering with CPU.  It's possible that you won't see any gain in performance with that card and you might see a loss.

The error message says 'Failed loading render kemel, see console for details'.


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how to set the alpha theme version in my new blender 2.8 version thanks
i download the new version blender 2.8, but i need to change the interface or theme in my new blender 2.8. isit possible?

"is it possible?" No, that is not a different theme

Blender 2.8 is in development, it's changing from one day to another. So you have to be ready to follow the changes. If you're not ready for that, wait for the actual release.

Have you tried User Preferences, experimentally? I am not making suggestions, but I wonder if User Preferences allow anyone UI choices. Can user keep the old looks of 2.79 interface inside 2.8?


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a line between the mirror looks strange, how can i fix this?
when I scaled the figure down i noticed that there is a ugly line that divides the character(like between the mirror). When I click on the eye symbol so that it shows just half, it looks good but I when its merged it looks odd. I tried to put the merge limit to zero but that didn't help.
is there any way of correcting this??  I have spent so much time on it that I'm paniking
ps im realy new to blender

Start by moving the SubSurf Modifier to the bottom of the stack (In general it should be last).

ok i have done that now. is there any difference if you put your subsurf modifier to the bottom of the stack in the end of the process? or do i have to remake the figure with the modifier in the bottom?

Don't delay modifiers order change, there's no reason to leave that to the end of modelling (in fact it can actively mess the model sometimes). In this case, half of your model is smoothed, including middle edge loop and hole it surrounds, then the mesh is mirrorred and the mirrorred part is smoothed as well. It is not what you want.

See https://blender.stackexchange.com/questions/353/how-can-i-make-the-mirror-modifier-work-right

As mentioned, you don't want to CC subsurf prior to a mirror with merge.  Once you get that sorted out...
It looks like your model's midline is not at the same location as its origin, meaning that once you mirror it, the margin doesn't get merged (which is probably what you would want.)
Try changing the origin of the model.  First, in edit mode, select your "midline" verts (the margin, not really midline in your unmodified mesh) and snap your cursor to this.  Then, using the 'n' properties shelf, manually place the Y and Z location of the cursor at 0.  Leave edit mode, select your model, shift-ctrl-alt-c origin to 3D cursor, (then alt-g reset position, not strictly necessary but a good idea.)  Now your model's origin is properly set at the same X location as the actual verts making up its midline.
In situations like this, it's not uncommon to have a midline that isn't totally vertical like it ought to be.  After fixing the origin, consider scaling all of your midline verts to 0 about the center in X axis only.  (Snap cursor to center, pivot point cursor, loop select your verts, s x 0.)


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Making Objects in the file or appending/linking them?
I've been learning about the append and linking function to bring in objects from other Blend files to the current one being worked on, but something keeps nagging at the back of my mind:
Aside from having already created the object for another blender file, why would you not just make the object in the current blend file instead of giving it it's own blend file and then appending/linking it?
Would it not be easier to make the object, say a window on a different layer of the blender file you are working in then copy-link it into the scene on a different layer instead of linking it from an external blender file? Is there any advantage in doing it either way or is it just a personal choice?


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Screen Space Reflection Flickering During Animation
I'm trying to eliminate the "bouncing" or flickering reflection of an animated object rendered using EEVEE.  I have a simple text object on a semi-reflective surface (specular 1.0, roughness 0.25) and screen space reflections enabled.  When the camera is motionless, the reflection appears fine, but once the camera begins to move even slightly, the reflections begin to bounce and jitter as seen in the clip below.  I'm somewhat (erroneously?) confident this is something to do with EEVEE's screen space reflections.  The bouncing disappears when I render in cycles.

So, what exactly is happening here?  I have played with each screen space reflection setting, but none seem to eliminate the flicker.  The Blender manual mentions using a reflection plane, but also mentions that you lose the effects of subsurface scattering, volumetrics, and screen space reflection/refraction, which is not desirable.
Maybe I've gone down the wrong rabbit hole, but other basic troubleshooting such as increasing samples doesn't have any effect.  Of course, turning off screen space reflections eliminates the problem ...and the reflection, which isn't desired.
Any thoughts?

This is why you should use EEVEE more as a low budget render, fast interaction before making the final render with Cycles.
EEVEE is real-time, therefore less quality. The flickering probably only gonna disappear if you turn off the screen space reflection and use raytraced reflections
You can also use later Blender releases that improve SSRF.
I've been using rasterized screen space effects elsewhere and that flickering appears constantly, so I confidently say it's inherent to kind of SS effects, so it's probably impossible to remove it completely, only to minimize by bumping EEVEE render settings.

Thank you for the response!  I appreciate the information.  It's good to know it's not just me.  :)

I know this is an old thread but I just encountered and solved this issue myself. Turns out if you scale objects too large you run into floating point accuracy problems. So in my case the solution was to cut the reflective surface up from one large plane to an array of smaller ones and the issue was fixed.