text:
Scale or resize?
Just a newbie question, but while selecting the "scale" from Transform the "action" panel shows Resize instead. Is this a bug or something which is not fully clear for new users?
So far I haven't similar on other Transforms actions.
--
Pepi

No,
   Scale actually means the size of your mesh. For instance (I am relating it to real life) you have a cube in real life then Suppose the length of the cube is 3 cm, width is 3 cm & height of that cube is 3 cm. It is the scale of the cube.
Scale:
on X-axis: 3 cm
on Y-axis: 3 cm
on Z-axis: 3 cm
If You increase the scale of that cube you are stretching it and actually you are increasing it's scale for example you stretched it & along X-axis through 2 cm. Then the scale of the cube will be
Scale:
on X-axis: 5 cm
on Y-axis: 3 cm
on Z-axis: 3 cm
Definition of Scale:
The relative extent of something; a thing's overall dimensions or magnitude; how big something is.
Clear Answer:
Its not a bug or something else. Its just name differently on the transform panel & action panel. The one thing I want add is that it is pretty clear to some new users but it can create confusion among some of the new users (really some of the new users most of new users will not find it a issue).

Thank you for your clarification. It is just slightly confusing, as you also describing the scaling while the action panel have "resize" :)
It is very clear that both terms means the same, but using both terms at the same time makes it not so clear.
But now I know, thank you about that.

@Pepi Please Accept my answer if you see that question is right!


text:
How eager Blender is about the GPU?
Just got my Fedora upgraded to version 27 and running there Blender 2.79. While using it I have faced a bit bad UI (it is not following what I'm selecting) or the who screen gets messy. See the exaple:

When I move the mouse, the screen gets updated correctly and suddenly it gets back to this. I started Blender with smaller screen, but then extended to full screen.
I do have a pretty old GPU: Radeon HD 6970 so I wonder could that be the reason for the behavior like this? So far, I haven't seen any other GPU related issues.
--
Pepi

source: Stack Exchange

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

sort: votes


text:
How to make plane to follow path?
I'm trying to make a long plane or similar to follow path, but the result does not look like I expected. Only the middle face is following path.

My idea is of course to have the full plane to follow the path. Any ideas from where I should try to looking for the solution? I wonder shall I try to use cloths modifier somehow.

I suspect you want the plane to deform along the curve. If so, you will get the desired result if you use a Curve Modifier instead of a Follow Path constraint (which i amuse u used.)

As Fjoersteller says your question is not clear, do you want to create an animation (Follow Path) or do you want your object to be deformed along the curve (Array + Curve modifiers)?

Yes, I would like to get that the whole plane is along the path. Both of you are correct, I should turn the plane 90 degrees, perhaps that could be then a bit more describing.
Moonboots, I do not want to use array, the parts should be together as scarf which is landing in spiral.
But thanks to both of you, I'll try curve modifier.

You can use an Array for that. If you click the check box next to Merge in the Array modifier, the object(s) will behave as one. (sorry for the a little bit late response)  : )

Hi there, back on this. It looks that curve modifier does not work if there is a loop or if there are all three axels involved to curve. At least I have not success to get this work.

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


text:
Why is object.origin_set(type='ORIGIN_CURSOR') not working?
def execute(self, context):
    stl_path = bpy.path.abspath(bpy.context.scene.stl_path)
    bpy.ops.import_mesh.stl(filepath=stl_path)
    try:
        ob_new = bpy.context.selected_objects[0]
        for f in ob_new.data.polygons:
            f.use_smooth = True
        for b in ob_new.data.polygons:
            bpy.context.space_data.show_textured_solid = True
            bpy.context.object.show_transparent = True
            bpy.context.scene.render.engine = 'CYCLES'
            bpy.ops.object.editmode_toggle()
            bpy.ops.mesh.select_all(action='TOGGLE')
            bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='FACE')
            bpy.ops.mesh.select_all(action='TOGGLE')
            bpy.ops.mesh.tris_convert_to_quads()
            bpy.ops.view3d.snap_cursor_to_selected()
            bpy.ops.object.origin_set(type = 'ORIGIN_CURSOR')

Everything is working well, until I use origin_set. Maybe I should go to object mode, after converting mesh to quads.
But when I'm adding bpy.ops.object.editmode_toggle() after tris_convert_to_quads Blender is freezing. Without this last command, everything is working, also snapping cursor to selected.

Ok, I changed script.
def execute(self, context):
    stl_path = bpy.path.abspath(bpy.context.scene.stl_path)
    bpy.ops.import_mesh.stl(filepath=stl_path)
    try:
        ob_new = bpy.context.selected_objects[0]
        for f in ob_new.data.polygons:
            f.use_smooth = True
            bpy.context.object.show_transparent = True
            bpy.context.scene.render.engine = 'CYCLES'
            bpy.ops.object.editmode_toggle()
            bpy.ops.mesh.select_all(action='TOGGLE')
            bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='FACE')
            bpy.ops.mesh.select_all(action='TOGGLE')
            bpy.ops.mesh.tris_convert_to_quads()
            bpy.ops.mesh.faces_shade_smooth()
            bpy.ops.object.mode_set(mode='EDIT')
            bpy.ops.mesh.select_all(action='TOGGLE')

to this line everything is ok, and script is ends in object mode.
but If I add this line
                bpy.ops.object.origin_set(type='ORIGIN_CENTER_OF_MASS')
I have msg in console, that I must be in object mode.
If i add this command
                bpy.ops.object.mode_set(mode='OBJECT')
Blender is switching off.

Any error message in the console? Also please add what your actual goal is.

You can't set the origin in edit mode.

Using try and catch will remove seeing error messages in console.

Also please don't ask same question again closed prior

You are right. To set object origin, you must be in object mode. You can also try using bpy.ops.object.mode_set(mode='OBJECT') to change to object mode.

Ok, I added this bpy.ops.object.mode_set(mode='OBJECT'), after converting to quads, and Blender freezes again :-(  When I added it after snap cursor to select, it happened the same

In console I have only information that, import finished in 1.2480 sec. My goal is that, that I have button, that import stl, converting to quads, changing origin to volume, and after it, is moving object with new origin, to 0,0,0

@Neuroup I have a fix for blender freezing. Before running the script, go to 'window' and click 'toggle system console'. Rerun the script. If blender freezes, switch to the console and press 'q' to terminate the operation. In my experience, this results in the desired output many times.

I started the system console as you wrote. When Blender crashed, I pressed the q key in the console (few times). Unfortunately, it did nothing. I just have a message that Import Finished in 1.2490 sec.

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text:
Dragon Project: Unwrapping issues
Here is what I have accomplished so far:

I have sculpted out what I wanted my dragon to look like
I re-topologized the dragon into a much less dense design.
I tried my best to unwrap this design to no avail.
I crafted a normal map (Which works very poorly)

I currently still use Blender 2.79 because I really like it, the main thing that I am trying to accomplish is to just one time get one model done all the way through.
I have sculpted a lot of my works, but every time I retopologize and then try to unwrap I always get a disgusting mess as a result. I have seen tons of tutorials on the entire process and I have never seen anything like my result.
So, sometimes when you have no other options you just have to take a step back and throw yourself on to someone's feet and beg for help. I really love this kind of art and have been stuck on this for months.
I have no idea what I'm doing wrong or even how to correct this issue. I can even send you my blend file for further observation if it will help.
This is my original completed sculpt

This is my re-topologized mesh

This is a representation of the unwrap that I have

These are the steps I took to apply the normal map

The seams are pretty bad and that you can still see that my dragon is polygonal as ever

https://drive.google.com/file/d/12t99_Vl1bkYhNsxou2SUD3qYkjIGotnd/view?usp=sharing

Hello and welcome :). You can share the .blend file through our Blend-Exchange site. Just remove all unnecessary parts and images to keep it as small as possible :).

Can we have a look at the texture, you're using? Also you might want to switch to smooth shaded when trying out normal maps.

Jachym, I will go ahead and share it now! I didn't know that we could do that!

Fredrick! I will put the whole blend file up on the blend exchange for you two! Thank you both for considering helping.

I am currently attempting to get this thing uploaded and have been for the last hour. It keeps getting stuck about a third way through.

To get useful answers try to ask more focused questions.
It's not really clear where exactly you're stuck.
Feel free to post as many specific questions as you need, that's what this site is for :).

To adress small technical issues:

Repair non-manifold vertices (Select > All By Trait > Non Manifold)
Align the centerline more precisely (to mirror properly)
Correct Face orientation, as some are pointing the wrong way
To get rid of the rough polygonal look, you can use 2 levels of Subdivision Modifier.

To align the centerline enable Absolute Grid Snap.
You can use Scale tool to align more vertices at once.

Other tips

Use more circular edge loops on your model for easier unwrapping
Add more seams when possible, to limit the stretching
Learn more about making Normal Maps (you can learn a lot on this site)
Try the new Blender Remesher (since Blender 2.82)

For art critique, you can try BlenderArtists.com.

Repaired mesh with some simple materials and a new UV map.

Thank you so much for at least taking a look at correcting the issues I had with my mesh! I really appreciate you even considering helping me.

No problem, I'm trying to unwrap it and it's really fun :). I'm learning a lot here, because I don't sculpt myself.

Jachym, Thank you so much! Just out of curiosity...how did you align the center-line more precisely? I am not sure how to do that.

I used grid snapping. I'll add a gif to the answer :).

Jachym, you saved me a big headache. I am going to take what you have done and apply it to my own model and then take it a few steps further. Thank you so much for taking some time to help a struggling novice!

Happy to help :). Please mark this answer as accepted ✓ for now. You can post new questions if you get stuck somewhere. Good luck.


text:
What options to grow object?
I tried to animate my object to appearing like from nowhere. I tried to use boolean's intersect modifier so that I had a box over my object which I animated from down to up.
Very much the same what Chris does on his example:
Sci-Fi Laser 3D Printer Effect
My issue was that sometimes my object totally vanished while the box was coming up and showing more about my object. Or when looking for this from top, there were no faces on up, like he had at 3:19 on his video. I believe the problem could be my object itself. I tried to fix that by merging the closest vertexes, but did not end to perfect solution.
I also tried to use build modifier, but that I feel was a bit uncontrolled, and really did not give the effect of "extrude".
Is there some other options which I did not thought to get similar effect? Or shall I try to continue to fixing my object to get this work?

You could use the Mask modifier.
First you need to paint some weights to vertices in Weight Paint mode.
Go to Weight Paint mode and select your object. Add a vertex group and select Gradient tool. Pull the tool across your object and it will paint the weights as can be seen in the image below.

Next go to Object Mode and give your object a Mask Modifier. Pick the Vertex Group you created earlier and adjust the Threshold. Threshold can be keyframed to make the object appear and disappear.

The more subdivisions your object has the smoother the appearing is.

Thank you Joonas for sharing this ! Great to see fresh new ideas :D
But there is the same issue than I had with my object, there are no faces.
My idea is to drop different objects into main object and then growing that until it is ready. And I believe it looks better if there are no missing faces on top.

Another option is to use the shape keys.
In Object Mode select your object and in Object Data Properties panel give it two shape keys. They will be named Basis and Key 1.

Select the Key 1 and go to Edit Mode. Edit your object as you wish.

Go back to Object Mode and change the Key 1 Value. Now you can see how your object changes shape or grows depending how you edited it. This value can be keyframed to create animation.

Thank you again, but unfortunately that does not work either. I have already existing model, and that I try come visible.
Perhaps I just need to model itself and see what errors I have on there to causing these strange behavior.


text:
Trying to import .OBJ from Magicavoxel to Blender, but it imports as a single large object?
I want to import a model from Magicavoxel into Blender that already has the desired colors and effects applied to them.
I imported it easy enough, but it seems to have imported as a single object which I can only edit as a whole. Also, while my colors transferred over, none of the light effects (certain areas glowing) were translated into Blender. I was hoping to fix this in Blender, but I can't select individual pieces of my build - it's all one object now.
It doesn't seem like exporting/importing with a different file format (such as .ply) helps in any way.
Is there anyway to either import my glow effects and lighting from Magicavoxel to Blender, or, import from Magicavoxel to Blender and retain each build piece as a single object (as it is in Magicavoxel) so I can edit them separately?
Please also note, while I consider myself computer-savvy, I am a beginner at both of these programs (less than 20 hours each of experience), so please spell things out for me.

Fortunately a plugin to import a .vox file without the need to convert to .obj https://github.com/RichysHub/MagicaVoxel-VOX-importer . Instructions on how to use it and caveats are on that page but will reproduce installation and basic usage instructions here:
Download io_scene_vox.py from the github page and install it into Blender.
In order to enable the add-on, you will need to have Testing add-ons visible within the Blender Preferences menu.

With the add-on installed and enabled, the importer can be accessed from File > Import > MagicaVoxel (.vox)

This add-on imports each voxel of the original model as an individual cube primitive. This opens up the use of voxel models for projects such as physics simulations.


text:
Unable to loop selection in certain mesh
I am a beginner. Today I met a problem, for some mesh I am able to do the loop selection, for example:

But for the circle outsdie this circle I am not able to do the loop selection, I can only select two edges at a time:

Could anyone tell me why it happened? Thank you!

@MikoCG Also a little question to your explanation. Do you mean that if I want to be able to loop select, the polygons that are connected to the vertices(I am going to do the loop selection) should have maximal 4 vertices?

the answer is very simple, the inner loop has good topology, with quads, outer topology has the wrong topology with 5 sided ngons, this is why you cannot select loop, you need quads with only 4 vertices, not 5 vertices (if you don't want to change topology, use Ctrl + LMB to select all edges)

that said I wonder why, when you select an edge, it even selects the next one

I double click the edge(which should be the same as Alt+LMB), it then selects the edge next to it

To extend with images:
This is your problem

It won't work if you have 5 vertices, because it probably doesn't know how to do the math behind it properly or something, anyway, an easy fix is simply to repair your topology and not make topology this way in advance to make it better, If I remove those extra 5th vertices, it works as intended:

As I said, another solution if you don't want or cannot to change topology, use Ctrl+LMB, it will select the shortest path between 2 points like this:

This can help you in this situation

Thank you a lot! The solution works.


text:
Cube not duplicating
I was working with rigid body cubes recently, and when I pressed ⇧ Shift +  D,  Z and moved it, and then I left clicked to do the action, but when i clicked it just snapped back where it was, and even if I try to move it, it snaps back again.

Has the cube you're duplicating some keyframes for the location? Or a baked simulation?

You probably duplicated your cube when your animation was on a frame more than your starting frame. So whenever you are duplicating an object with a rigid body simulation always go to the starting frame of the animation and then duplicate your object.

But if your object has some keyframes assigned to it then the story is different and this is not the issue.


text:
Calculation of surface area of 3D model, then color filtering
I just got into blending and 3D modeling and I'm still not sure I understood how UV cards work.
I made a textured 3D model using the photogrammetry technique.
The idea now is to calculate the area of my model where the color is green.
The first idea that came to me was to work on the model's UV map.
Step 1: Calculation of the total number of pixels of the UV map.
Step 2: Calculation of the total surface of the model.
Step 3: Calculate the number of green pixels in the UV map.
Step 4: Cross product to determine the green surface of the model.
However, by having gone through the various topics relating to similar problems, it seems to be more complicated.
One of the solutions seems to be to browse my 3D model and use the calc.area function
(or something like that -> How to get the value of face area using python ) on each face of each mesh, having also filtered out the colored (green) meshes upstream.
It is therefore necessary first of all to extract the RGB value of each face corresponding to the pixel (UV coordinates) of my texture image, in particular using a baricentric average calculation.
-> Get RGB value of texture from face on mesh
Do the proposed solutions seem viable to you? I accept any remark.

You sound extremely confused as to what a UV map is and does. A UV map has no pixel size. Each vertex in the UV map has a factor (IE 0 to 1) position on a two dimensional plane. Those two dimensions are U and V. The idea of a UV map is to tell Blender how a two dimensional image should be folded over a three dimensional object.

Yes, I am, but maybe less than you ...
There are definitely some colored pixels in the UV map. I never spoke of "pixel size". I'm just wondering if it's possible to relate the pixels of the UV map to the surface of the 3D model.
I understood that the UV map was used to correctly place the vertices on the 3D model.

No. UV Mavs are completely independent of images, and have no color association whatsoever.

Maybe I'm talking about the texture file that goes with it ...

That makes more sense. The first method you described would of course not work because most of the image could be squashed onto one tiny face in the model, while the rest of the image was stretched over the vast majority of the model. The second method sounds like it would work at least to some degree. How precise does this need to be? What are you really trying to achieve?

I m trying to have an estimation of a surface vegetation parameter, in fact : the "green" surface of a bunch of vegetation, which represents the capacity of photosynthesis of the plant.


text:
When to texture paint to paint on Mesh and when to use Photoshop to paint on 2D Texture
I recently found two workflows for texturing, painting directly on the model and painting over a 2d texture file. In what situations are you supposed to use which? I have noticed that it is hard to texture seamlessly with PS when there is a cylinder with a wood texture. In this case it feels like texture painting is the way to go. Is this correct?
Or is texture painting the newer way of doing things? And 2d texturing is outdated?

The concept behind UV unwrapping is to assign to every 3D vertex a 2D coordinate.
If you are working with a flat plane, the two approaches are nearly the same (generally a 2D software is more powerful).
If you're working with a 3D object, direct painting on the 3D mesh is gratifying but generally it's difficult to get a really powerful control of what you're actually doing.
Working on 2D UV unwrapped textures is more controlled but more complex, at first.
Like many tasks, you can reach your goal in many different ways: the complete path for texturing a cylinder is:
1) create seams on the mesh, unwrap it, assign an  image texture (the seam will be visible)
2) delete seams, create new different seams and create a new UV map
3) bake the texture on a new image
4) doctor the new image in a 2D editor (seams to be doctored will be visible, don't touch image's boundries, as it would create new visible seams)
5) use the new image with the 2nd UV map
This complex procedure will assure a seamless texture in any situation, generally it can be avoided by hiding the seams in hidden places.
As you can understand there is no "better" or "old" way. It depends on your needs.
Personally, i stopped studying 3D paintings because even a simple open source software as GIMP let's me reach better results than Blender Paint capabilities.

It depends on developers, few fixes to 3D Viewport \ Texture Paint, and Blender's Image Editor will be just an outdated version .
2D editing software has more functions, but its only until someone port them to 3D .

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


text:
Best way to do repetitive rigging?
I am trying to rig a flower which has multiple pedals. In order to save time, I want to rig and weight paint for only one pedal and duplicate those pedals.
The constraint I have is that I want the armature to be one armature, instead of having multiple armatures. This is because I am using this rig, outside of blender. Additionally, (although not required) I want to have the flower as one mesh.
The main problem I have with this is either

When creating pedals in a different object then joining it together, since the vertex group names are the same when duplicating, the pedals just end up following the original bones that I have created
When creating pedals in edit mode, I can't manipulate the armature in edit mode so I end up having to duplicate the pedals first, then going to armature and duplicating bones, and weight painting for each pedal, which is a very long process.

So since no one replied, I guess writing a plugin was the best bet.
In case if anyone wants to take a look at it, here is the link
https://github.com/shuao23/DuplicateToolsForArmature
Just a warning, there might be bugs so backup before you use it. Also its not super flexible so don't expect much :p


text:
Outliner -> vertex group select, not yet implemented: is it a bug?
Blender 2.69 on Ubuntu 14.04..

I don't think you can select the vertex groups via the outliner (because it is not yet implemented), but you still have to select it via the properties panel --> Data object data --> vertex groups
(in version 2.75 it is also not yet implemented)

How is it still not implemented over 4 years later?


text:
Displace adds an extra noise
Anybody knows if I can limit the noise generate by displace modifier? On my test I have used a picture like following.

But the results are like this:

There seems to be unexpected noise on the edges. The problem comes worst when I try to subdivide the plane over 100 times. Subdividing I'm using to make smooth edges.
Here is a screen capture from original file showing that there were only two colors used on the edges. The yellow rectangle on blender picture shows the place where this part has been taken when the original image has been zoomed in 600%.

Those look lot like jpeg jaggies, was your displacement map ever a jpeg?

Yes it is, only a jpeg..
So basically what you are saying, I should have subdivided double (at least) compared to the image resolution to having clear edges?

Why do you need displacement?
For a shape like this it would be a lot easier to create clean geometry and with a lot less vertices.
Or trace the shape as path in a vector drawing program (inkscape, illustrator, etc) and save as SVG to import back to blender.
Diagonal lines will always be jagged in raster formats (and in this case you see clearly how compression creates other artifacts).

This was just an example. I have a logo picture, and that I try to make it to 3D model and I though displacement would be the easiest way to do it. Then I hit to the noise issue, and I wonder if simple pictures do have the same issue. So now I'm here :)

For logos use SVGs Displacement, as you experienced, will never give you straight lines, and you need many subdivisions for a clean displacement. On top of that the quality will always be determined by the size, resolution, compression and bit depth of the image.

Okay, thank you for your alternative idea. The logo is unfortunately on jpeg only. But let see how Inkscape can help me with this :)
Thanks and have a great day !


text:
How to make a van follow the road's L/R tilt
I have a van model with a Follow Path constraint, so that it moves following a curve. The curve itself was first shrinkwrapped on the road below, so that it follows its shape. Lastly, a camera is parented to the van, so that it moves together with it, creating an animation.
Everything works as intended, except for one thing: the van+camera doesn't tilt/rock left or right when the road is inclined perpendicularly with respect to the direction of movement. Just to be clear, the van+camera does correctly follow the road uphill and downhill.

Here you see the van+camera rig just before the beginning of a sloped road that would require the van to "rock" L/R, with the right part above the left one, and the camera tilted accordingly as well.
How can I achieve the effect I am looking for?

you have to check "follow curve" and (!) you have to tilt your curve manually - the shrinkwrap doesn't do that for you - unfortunately.

Thanks for your answer. "Follow curve" is already enabled, and it makes the van correctly curve together with the road. Can you tell me more on how to tilt the curve manually? if it can be done manually, maybe it can also be somehow "automated" on the basis of the road below?

Sorry, I have seen now there's a "tilt" slider when selecting the curve in edit mode that does what I want. But, again, if it can be done manually, maybe it can also be made to follow the road below? Any suggestions? Thanks again!


text:
How to Extend the Plane and make it snap it to the Landing?

I want to extend the plane at the same angle and snap it to the landing
I am unable to extend the plane at the same angle and snap it to the upper landing.

Edit mode
turn on Snap to Face
Select wanted Edge
Edge Slide (G-G)
Hold Alt to turn off clamping
Slide to intersecting plane

Thanks a lot :)

Glad it helped.


text:
how to make an object like a flat?
I am new to Blender.
According to my toturial, I have to create an abject like a flat.

He hit F and the object changes,
but when I hit F in my object, it does not change

I am using the blender 2.81

Hello :). Check the video again, he probably just inset the top face by pressing I, not F.

hello :) . in the first picture you can see he hit F.I mean in the left of the picture.

Sure. He hit F (to add the top face) while in Edit mode. Timestamp 10:02.

oh.What a bad mistake :( . thank you :)

No problem :). Good luck with your project.

The reason this happens is because you have 'subsurface' modifier enabled.
What subsurface modifier does is basically adds extra geometry to your mesh.
In your case, the type is set to Catmull-Clark which in short will basically smooth out your mesh.
So if you start with a basic cube

and apply the modifier on it, it will smooth it out and it will start to resemble a circle

Now an easy way to make the object look like what you want it to be is add extra vertices where you want the detail. So if I were to add some extra vertices at the corners of the cube it will start to resemble the cube again

Now if you understood this you would have guessed you need to add extra geometry in your mesh at the top of your coffee(or water? depends on how far you are in that tutorial)
An easy way to add geometry to a closed loop is the inset tool(hotkey I), this tool basically makes another smaller loop inside the loop and connects the vertices.


text:
Stuggling to UV Wrap Can
I am trying to UV Wrap the can in the image but I am struggling with how to design my label so it fits the correct curve of the UV map.
I tried warping my image in Photoshop but I just couldn't make it look prefect. Is there an easier way in Blender?

https://blender.stackexchange.com/questions/74041/how-to-perfectly-align-uv-coordinates-automatically/74045#74045 https://blender.stackexchange.com/questions/78358/how-to-straighten-curved-uvs-into-straight-belt/78376#78376

You can use UV>Cylinder Projection with your surface faces selected. Just make sure you don't select the bulging parts on top and bottom. They have to be mapped seperately, as well as the top and bottom caps. (Don't use Live Unwrap to avoid your UVs getting messed up)

BTW: If you don't want to deform your can later on, you can save a lot of geometry in your model (and even then, you can always add more geometry later, while it's more time consuming to remove unwanted geometry).
You don't need any of the edge rings between the two shape defining ones at the top and bottom. It's always good to keep the polycount low, be it for vfx or games.


text:
Not able to see saved UVs in UV layers in Blender 2.8
Having difficulty in viewing of saved Uv layers in Uv Map they are unsaved.
If I unwarp a mesh of an object in a new UV layer and go to the next layer unwarp some other part of mesh and if I go back to previous layer that unwrapped mesh is not visible or sometimes its not saving.
So my issue is if i go to any UV layer in UV Maps palette am getting fresh board and no saved UVs at all in UV editor. Actually UV layers how I need is if i switch over to any UV layer I should get proper saved unwrapped UVs.
So how can I fix this issue?


text:
Is it possible to use an image to edit a mesh to the image's size?
I wanna make it so that the mesh i have is cut out in accordance with the transparnt png. So, i have a png with a drawing on it, and a transparent background, is it possible to change the mesh shape so that the background is gone, and the mesh changed shape in a way that its the drawing.

Its not possible, but if i have a vector image i can import it as a curve, and then convert it into a mesh

No, this is not possible with any image. If you have a vector image. you can import that vector graphic as a curve, and then make it a mesh, but this isn't possible in general with a rasterized image.

Inkscape https://inkscape.org/fr/ could do it, depending on the picture you start from. https://www.youtube.com/watch?v=R6dgW5J0Osw and you can import to blender after that.

There are two methods I'm thinking of.
The first is using an SVG of the image contour.
Loading the image in Blender Using Import Images As Planes.
Import the SVG.
I converted the SVG to Mesh and applied the same material of the image.
The second try is using the Knife topology tool ( K ) direct to the imported image to cut the subject. No need for a vector-based program. Delete the unwanted faces.
This method was faster because all is done inside Blender.
Note we have to do short cuts to smooth corners.

I use a camera view matched to the image dimension so I can project from view to align correctly. Good answer.

Possible with a lot of thing to do,
First, in order to find the contour of the image, you might want to use OpenCV library to find it.

In newest blender python, it is allowed to use pip to get OpenCV package. So it is not that difficult.
Second, you somehow need to let the vector-based mesh in Blender to transform as pixel-based contour data.
If you want to only move the existing mesh vertices without adding any extra vertex, you will need to let the vertices move to the most similar part of the contour. Many method, calculating the description vector will be a good idea.
Or new vertices is fine, then turning contour into vector image will be an good idea. There are a lot of packages that could handle this problem. After that, using those vector
to define new vertices into your mesh and delete(or moving) the original vertices. Also curve is an good option to prevent a lot of unnecessary triangle.


text:
Blender 2.8 material not applied to separ
I have created a separate object from vertexes in an object (pressing P ). The object gets created but I can't seem to apply materials onto it.
The selected object ("Facade") doesn't change when different materials are added to it:

It should have a light brown color (same as the base of the building).

Since the facade is now a separate object, it doesn't need all those other materials in your list and is probably applying the first one - try (1) removing all except the one you want to apply or (2) go into edit mode, select all faces and press 'assign' with the material you want applied.

Tried unlinking all materials, relinking the material I wanted and created a separate material altogether. All failed.

I've managed to change the material by selecting faces (Ctrl + L does this more quickly). Click assign after selecting faces and changing material.
I sometimes manage to create a new object from vetexes and then assign a material to it. Sometimes, I can't. I really have no clue as to why.


text:
Solidify completely distorting

Pic1:The donut
Pic2:Adding Solidify
Pic3:Change offset
I am doing the Donut-series and have managed to apply solidify to the icing a couple of times before without any problems.
Now Solidify creates a completely distorted image. I have searched for answers and made sure I've applied scale, as suggested, before using solidify as directed in the tutorial.
I have closed, restarted Blender and tried very meticulously every step but can't get passed this.
I must have hit a button without understanding what I've done, it worked fine the first couple of times I tried.

Hello could you please share your file? https://blend-exchange.com/

Hello I think I have uploaded now but I cannot see the result.

Hello, you need to share the link it gives you

Hi, I dropped the file in the box (in the link you shared) and the url asked before uploading. It seemed right since it uploaded, butI did not see anything added to my question. What shall I do?

you need to copy the link it gives you and paste it here  ;)

"it gives you"? I am really so sorry, and I so appreciate you haven't given up yet, but uploading my blender file was easy, as was copying the url when at my question, so I am still not sure of where to find what you need.... I'll repeat the procedure and see if it works better!

https://blender.stackexchange.com/questions/287187/solidify-completely-distorting

Or maybe you mean the url after I uploaded? https://blend-exchange.com/b/e6SRaE1g

Your Solidify is very thick because your object is very small, scale it up, apply the scale (CtrlA) and it will work fine:

Thank you, thank you, thank you!!!! You are my hero :))) Yes it works fine now once I double checked the Donut instructions and realized I'd shrunk it waaaay to much..... I can not thank you enough! :)


text:
Make object Steady problem in certain part of Animation
I’m fairly new to blender and I was working on creating simple backpack animation for my unreal game.
In my game, backpack will be always attached on my character’s “spine_05” bone. So I need an animation but it must be Child of “spine_05” in whole keyframes of animation.
In Blender, I set parent of backpack and I made an animation

But I have problem here, I want to make steady Backpack object, as you see in the red circle from 45th to last keyframe. I shouldn’t break child contraint or modify its influence in the animation.
This is blend file: https://drive.google.com/file/d/1wEoN01s8A8lc4W96A1e3JpJzkaB14KQp

may i ask why you cannot change/keyframe the influence? because that's exactly the use case of influence: To "unchild" temporarily the child constraint. And this is obviously what you want in that case. But if you exclude the obvious "solution" as prerequisite...it will be difficult to solve your problem.

As I mentioned, this animation will be always played on character's spine as a child. So I couldn't break child constraint. If i do, I have to break on the game engine too and I don't want it.

Create a Backpack bone, set a child of bone constraint targeting the spine bone and set the backpack child of the new bone (do not confuse object constraints with bone constraints).
Then program the animation in Blender, using the influence slider when needed (use the "Copy World Space" addon for fast programming).
Then select the new bone in pose mode, go to menu Pose > Animation > Bake action (Only selected, Visual keying, Clear constraint, Overwrite current action), so to end up with a clean animation without relying on constraints and influence sliders.

I don't fully understand you, it's probably because I'm new to blender. Could you please apply to blend file your said?


text:
Can I prevent user from importing a non-existant or incorrect file in an import operator?
Losing my Blender flower on this one :)
I'm using an operator to select the filepath of a .txt file.
import bpy

class SelectTxtFile(bpy.types.Operator):
    bl_idname = "file.select_txt"
    bl_label = "Select TXT File"
    bl_options = {"REGISTER", "UNDO"}
    filepath: bpy.props.StringProperty(subtype="FILE_PATH")
    filter_glob: bpy.props.StringProperty(default="*.txt", options={"HIDDEN"})

    def execute(self, context):
        print(self.filepath)
        return {"FINISHED"}

    def invoke(self, context, event):
        context.window_manager.fileselect_add(self)
        return {"RUNNING_MODAL"}

def register():
    bpy.utils.register_class(SelectTxtFile)

if __name__ == "__main__":
    register()

    bpy.ops.file.select_txt('INVOKE_DEFAULT')

I don't want the user to be able to validate the operator (Blue button) if the file they selected isn't a valid .txt file.
I want the button to be clickable only when :

The user selected a file and it exists : os.path.isfile(path) returns True
The extension is .txt : os.path.splitext(path) returns ".txt"

I would like to insert this line somewhere :
layout.enabled = os.path.isfile(self.filepath) and os.path.splitext(self.filepath)[1] == ".txt"

I'd like it to be grayed out if the conditions are not met. But I can't access this particular layout button because it's apparently managed by the window manager.
How can I achieve that ?

Looks promising https://docs.blender.org/api/current/bpy.ops.file.html#bpy.ops.file.execute  re the need_active parameter   Maybe related https://blender.stackexchange.com/a/207665/15543

@batFINGER That looks exactly like what I'm looking for and I learned a lot from your answer and related threads, but I still can't seem to access that particular operator to change this parameter... I'll keep looking :) I'm starting to wonder if I can just remove this bottom strip with the filename, operator and cancel button and redraw it myself.

dig into wm.fileselect_add which AFAIK invokes  the filebrowser to run modally and  appends  the footer. Highly  recommend  pathlib over os.path shenanigans


text:
How can I assign material colors to a color attribute?
For the record I'm asking this question because it was brought up by a member recently and deleted under my eyes while I was clicking on the submit answer button, but I think it was a worthy question and I'll share my answer.
The premise was :
I have an object with materials assigned to its material slots. The materials are assigned to the object's polygons. Each material has a simple node tree with a single principled BSDF node with a specific base color.
I want to create a new color attribute on the object's mesh which will assign each polygon with its corresponding material color.

" it was brought up by a member recently and deleted under my eyes" - I can relate, happened to me in the past… Duarte said to ping a mod in such a case. The question mentioned is this - I myself decided not to answer it because of seemingly low effort of OP (I always wonder if someone uses AI for the script, does he also use it to word out the question...)

Thank you @MarkusvonBroady I didn't know this was the procedure, it makes sense. About the AI generated part, the body of the question was clear enough for me to understand the goal, and the script albeit flawed confirmed my assumptions, so in this case I didn't mind. I also recently used the attribute API for another project so I thought why not. Honestly I'm not so much worried about AI content inside the questions so long as it is understandable. What should be forbidden IMO is raw AI content in the answers. Cheers !

Here's an example script. I'll assume you use V3.6+

Create a new color attribute
Iterate over all materials and
fetch their color
Iterate over all polygons and fill out the
correct colors into the polygon corners.

Note non-assigned materials or materials with no principled bsdf node will have a black color.
You should be interested in reading bpy.types.Mesh, bpy.types.MeshPolygon, bpy.types.AttributeGroup and bpy.types.Attribute.

import bpy

def main():
    obj = bpy.data.objects.get("House")
    if obj is None or obj.type != "MESH":
        return

    mesh = obj.data
    color_attribute = mesh.color_attributes.get("Color")
    if not color_attribute:
        color_attribute = mesh.color_attributes.new("Color", "FLOAT_COLOR", "CORNER")

    materials_colors = []
    for material_slot in obj.material_slots:
        material = material_slot.material
        if material is None:
            materials_colors.append((0, 0, 0, 0))
            continue
        principled = next((n for n in material.node_tree.nodes if n.type == "BSDF_PRINCIPLED"), None)
        if principled is None:
            materials_colors.append((0, 0, 0, 0))
            continue
        materials_colors.append(principled.inputs["Base Color"].default_value[:])

    for polygon in mesh.polygons:
        for corner_index in polygon.loop_indices:
            color_attribute.data[corner_index].color = materials_colors[polygon.material_index]

if __name__ == "__main__":
    main()


text:
Where is Smoke in 2.83.10?
I am trying to create something that requires the Physics > Smoke and it's not shown on my physics panel. The version I'm using is 2.83.10 and I have included a screen shot of my physics panel and on from a YouTube tutorial screen shot using the same version [ a tutorial physics tab .
In the Blender documentation online it shows the panel has a Smoke setting for creating a Smoke Domain. Did it move to another location? Or is it in an Add-On in the preferences?

The smoke and fluid simulations changed with the introduction of mantaflow
The settings are in Fluid.

To create the smoke emitter, or Flow.
Set the Type to Flow
And the Flow Type to Smoke.

For the Domain
Set the Type to Domain
And the Domain Type to Gas

For a simpler way to set flow and domain simultaneously, just select the object, press F3 and type quick smoke.

Thank you for the reply and also thanks for the f3 shortcut as well.


text:
I try rendering a video in render but the whole render goes black
I'm Testing the BGCV VHS Look on Blender based on this video.
I used a MP4 video as a base and I've followed the instructions correctly, however when I render the video the whole video is black.
The audio is still there but the video is missing, I'm b beginner in Blender so I don't really know how to fix this.

What happens when you do a simple render (F12)?

I tried doing a Simple Render, The Render is also Black.


text:
How can I get Infinit Reflections on Cylces
I have this circular room with mirrors instead of walls, but when I go to the render tab, at some point it gets black, how can I make the mirror material have limitless reflections?
I'm using the latest version of blender 2.82, an my mirror material its a Principled BSDF full metallic no roughness.

How to take a ScreenShot

U save my life!, thank u

You need to increase the number of Light Bounces.
It cannot be infinite, but it doesn't need to be.

head to Render Tab > Light Paths > Max Bounces
adjust both the Glossy value and the Total value to your liking
to look infinite, the latest reflection needs to be of 1px size

How many Suzannes do you see...?


text:
ColorRamp on glass animation bug?
I used in one of my projects a Color Ramp on glass texture.
At first all seems to be perfect at the beginning of the animation, but at the middle the Color Ramp on the middle streaks and smallest streaks is going to turn white for a few frames and normal and white etc.
Did I do anything wrong, or is it a bug?


text:
Smoothness between (Dup)Mirror and Orginal?
Hi I am modeling a truck, I modeled its half part and dup + mirrored it for other half. I have a problem and both parts haven't smoothness between them ?
How can I make them smooth ??

Thanks

Can you provide the screenshot representing the grid of your model?

Can we see the order of modifiers on the truck?

If you are using a mirror modifier, is Clipping enabled?


text:
Character bouncing on models
I've imported models from Blender to Unity in .FBX and the model in the game makes the character bounce/jump heavily, and it makes the game unplayable.


text:
Exporting multiple meshes individually at once
I need to export around 200 meshes into FBX, individually, organized with object names. The old method I used before was creating an export preset and export them one-by-one, with the right names. That was bearable with 70 meshes, but rather frustrating with anything beyond.
So my question is the given:
Can I export 200 meshes into 200 files with their object names as names?
I have a few complex, animated meshes that I would rather export the old-fashioned way, but if I could skip the other 190 meshes, that would be sweet.

Too little information for writing a script. No list of FBX settings you need, no principles by which objects are meant to be determined by the script for the separate export. Too many probabilities, I'm afraid.

You are right. I didn't specifi that I need to export them 1.00 Scale, apllied Local Scales with -Z forward / Y up and applied Unit and Transform. I'm sorry for the lack of information.

Addon based on this answer, adapted to export all meshes in selection to single fbx files.

# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####
# <pep8 compliant>

bl_info = {
    "name": "Batch export FBX files",
    "author": "brockmann",
    "version": (0, 1, 0),
    "blender": (2, 80, 0),
    "location": "File > Import-Export",
    "description": "Batch Export Objects in Selection to FBX",
    "warning": "",
    "wiki_url": "",
    "tracker_url": "",
    "category": "Import-Export"}

import bpy
import os

from bpy_extras.io_utils import ExportHelper

from bpy.props import (BoolProperty,
                       FloatProperty,
                       StringProperty,
                       EnumProperty,
                       CollectionProperty
                       )

class Batch_FBX_Export(bpy.types.Operator, ExportHelper):
    """Batch export objects to fbx files"""
    bl_idname = "export_scene.batch_fbx"
    bl_label = "Batch export FBX"
    bl_options = {'PRESET', 'UNDO'}

    # ExportHelper mixin class uses this
    filename_ext = ".fbx"

    filter_glob = StringProperty(
            default="*.fbx",
            options={'HIDDEN'},
            )

    # List of operator properties, the attributes will be assigned
    # to the class instance from the operator setting before calling.

    # context group
    use_selection_setting: BoolProperty(
            name="Selection Only",
            description="Export selected objects only",
            default=True,
            )

    use_mesh_modifiers_setting: BoolProperty(
            name="Apply Modifiers",
            description="Apply modifiers (preview resolution)",
            default=True,
            )
    axis_forward_setting: EnumProperty(
            name="Forward",
            items=(('X', "X Forward", ""),
                   ('Y', "Y Forward", ""),
                   ('Z', "Z Forward", ""),
                   ('-X', "-X Forward", ""),
                   ('-Y', "-Y Forward", ""),
                   ('-Z', "-Z Forward", ""),
                   ),
            default='-Z',
            )
    axis_up_setting: EnumProperty(
            name="Up",
            items=(('X', "X Up", ""),
                   ('Y', "Y Up", ""),
                   ('Z', "Z Up", ""),
                   ('-X', "-X Up", ""),
                   ('-Y', "-Y Up", ""),
                   ('-Z', "-Z Up", ""),
                   ),
            default='Y',
            )
    global_scale_setting: FloatProperty(
            name="Scale",
            min=0.01, max=1000.0,
            default=1.0,
            )

    def execute(self, context):

        # get the folder
        folder_path = os.path.dirname(self.filepath)

        # get objects selected in the viewport
        viewport_selection = context.selected_objects

        # get export objects
        obj_export_list = viewport_selection
        if self.use_selection_setting == False:
            obj_export_list = [i for i in context.scene.objects]

        # deselect all objects
        bpy.ops.object.select_all(action='DESELECT')

        for item in obj_export_list:
            item.select_set(True)
            if item.type == 'MESH':
                file_path = os.path.join(folder_path, "{}.fbx".format(item.name))

                # FBX settings
                bpy.ops.export_scene.fbx(
                        filepath=file_path,
                        use_selection=self.use_selection_setting,
                        use_active_collection=False,
                        global_scale=self.global_scale_setting,
                        apply_unit_scale=True,
                        apply_scale_options='FBX_SCALE_NONE',
                        bake_space_transform=False,
                        object_types={'EMPTY', 'CAMERA', 'LIGHT', 'ARMATURE', 'MESH', 'OTHER'},
                        use_mesh_modifiers=self.use_mesh_modifiers_setting,
                        use_mesh_modifiers_render=True,
                        mesh_smooth_type='OFF',
                        use_subsurf=False,
                        use_mesh_edges=False,
                        use_tspace=False,
                        use_custom_props=False,
                        add_leaf_bones=True, primary_bone_axis='Y',
                        secondary_bone_axis='X',
                        use_armature_deform_only=False,
                        armature_nodetype='NULL',
                        bake_anim=True,
                        bake_anim_use_all_bones=True,
                        bake_anim_use_nla_strips=True,
                        bake_anim_use_all_actions=True,
                        bake_anim_force_startend_keying=True,
                        bake_anim_step=1,
                        bake_anim_simplify_factor=1,
                        path_mode='AUTO',
                        embed_textures=False,
                        batch_mode='OFF',
                        use_batch_own_dir=True,
                        use_metadata=True,
                        axis_forward=self.axis_forward_setting,
                        axis_up=self.axis_up_setting
                        )

            item.select_set(False)

        # restore viewport selection
        for ob in viewport_selection:
            ob.select_set(True)

        return {'FINISHED'}

# Only needed if you want to add into a dynamic menu
def menu_func_import(self, context):
    self.layout.operator(Batch_FBX_Export.bl_idname, text="FBX Batch Export (.fbx)")

def register():
    bpy.utils.register_class(Batch_FBX_Export)
    bpy.types.TOPBAR_MT_file_export.append(menu_func_import)

def unregister():
    bpy.utils.unregister_class(Batch_FBX_Export)
    bpy.types.TOPBAR_MT_file_export.remove(menu_func_import)

if __name__ == "__main__":
    register()

    # test call
    #bpy.ops.export_scene.batch_fbx('INVOKE_DEFAULT')

I added all possible arguments of the fbx operator (line 125), you can change them or add new properties to the operator, wasn't sure.

Works like a charm. Out of the two answers this works the intended way, as it is easily customizable. Thank you for your assistance! You got the bounty!

Only question I have is how can I delete export options? I didn't get the desired effect on the first try and after altering a thing or two I ran the script again and now I have 2 of them.

Cool @505Legion Easy, no problem to edit the script, just let me know. Install it like any other add-on instead of running the script in the text editor (because it is an add-on actually). Save the script as eg. io_export_batch_fbx.py using a text editor of your choice, in Blender User Prefs > Addons > Install. What else?

Here is a screenshot of my problem, as it might have been a bit misleading.
https://imgur.com/fiRjQ3u
As you can see I have 2 individual FBX Batch Export, an FBX Batch Export 2 and an FBX Batch Export for Unity. At first I expected that running the script will override the previous one, instead created a clone, so to make sure I'm using the altered one, I ran it again (added the number "2" to its name). After that I ran it with the actual name I needed it with ("for Unity"). I want to keep the latest one, but would like to get rid of the rest. How can I do so?

Seems like your solution (saving and using it as add-on) worked just fine, I just had to restart Blender facepalm. Now all the duplicate options are gone. I have no other complaints about the script. Thank you once more.

Is there any chance that anyone would adapt it for .MDD files ? :s

How can i translate all the models to the center?

Save your blend file in the directory you want the objects to be in.
Head over to the Scripting workspace
In the editor window: Templates -> Python -> Batch Export
Select all objects that you want to export
Run the script with the Play button

Smart! (no more to say but needed 15 chars to add the comment)

It worked, but sadly it appears I gave you too few information on the way how these are supposed to be exported (as later commented) and the other answer gave a better result as that is greatly customizable. Your answer is still a viable option and I'll keep it in mind. Thank you very much!

Just Tick Obj Groups And Untick Others

The question is about exporting to fbx, not obj (yes, they are different). More than that, options you mention don't mean exporting each object into its own file, rather exporting multiple objects to one file and keeping objects as separate (not joined into one)


text:
Blender Cycles - How to make particle planes to face towards the camera?
So I've been working on an explosion, with textured planes coming out of a particle system. Too bad it destroyes the whole feeling, when I can't see the texture on one of the planes, but a line, which is the plane, but not aligned to the camera. It also makes the middle of the explosion seen by the camera almost fully invisible, because there are no planes aligned to the camera. I tried to "Track To" the parent texture plane to the camera, but it only worked for that specific object, not the partices.
I couldn't find any solution not even on YouTube or Stackexchange so I'm asking you for help :)

This may help https://www.youtube.com/watch?v=MqBIAE8A-4k

It seems to fix this issue, when I enable "Rotation" under the duplicate object selection in the Particle System settings.


text:
How to make textures in Blender without any flat work with a painting program? (3D painting)
I've made a complex model, what would be a nightmare to texture in gimp. So I'm asking you, if there is an option to paint in Blender itself, watching my 3D creation? It would be a lot easier and faster that way. If you need the model, just ask for it. Oh, and I've added armature to it. Will the texture follow the body while it is deformed?

texture paint mode, same menu as object/edit/weight paint modes in 3D view

I think you can use a Texture Paint mode and paint the textures using a Stencil option.
Add a new material to your object. Join all the meshes using Ctrl+J. Unwrap the model using Smart UV Project.

In Uv Editor add a new image texture and name it. Then save it (Image-->Save as Image).

In CYCLES Setup the nodes as pictured below. In the Image Texture node open up the newly created image.

In BLENDER INTERNAL RENDER add a new Paint Slot-->Diffuse Color in a Tools bookmark of a Tool Shelf (T).

Enter the Texture Paint mode and set up the shading type to Texture. Add a new texture in the panel on the left, then go to the Texture header on the right, select Brush and open a texture, which will be used as a stencil for painting.

Enable a Stencil option in a panel on the left. Press:
-LMB to paint through the stencil
-RMB to move it
-Shift+RMB to make the stencil bigger and smaller
-Ctrl+RMB to rotate it.

You may also uncheck the Occlude, Cull and Normal boxes to paint on the invisible parts of the mesh.

Save your image when you're done with painting.

Thank you. I guess I can use this too, but I'm working with simple textures first.


text:
Rigging two handed weapon
I have created a model, which is meant to hold a two handed weapon, but I don't know how to make both hand to move with the weapon. The weapon only follows the right hand now. I want the left hand to hold onto the weapon, while I move the right hand with the weapon in it. Back then, I saw tutorials about animating, containing the required information as a bonus, but I can't find them, so I'm asking you.
If you can't understand something, please tell it to me, so maybe I could explain it better.

You may use some IK (invert kinematics) and some constraints to do this kind of things.
I did a very basic model to show that :

I presume you know how to parent a mesh to an armature, but if not, please leave a comment and I could complete that.
The body is parented with automatic weights.
The gun is parented too, but all the weights are given to the root bone.
The right hand has a IK constraint with a chain length set to 4 in order to end at the shoulder (the yellow line you can see in the gif above) :

The left hand is done the same but it target an empty indicated by the green arrow :

The gun now : its root bone has a constraint in order to follow a little bone of the man armature parented to its right hand. This allows the gun to follow this hand :

The empty has a constraint too which makes it follow the gun extremity, which is the bone indicated by the arrow in the 3D view below :

So, to summarize :

The gun follows the right hand
The empty follows the gun extremity
The left hand follows the empty

But in some situation surely, you want to free the left hand, because the man position needs it. So simply lower the influence of the left hand constraint to allow it to come back in place. You are also free to move it independently :

I'm following the steps, but I cannot set "Empty" as target on the left hand's IK. Is "Empty" an other object or is it a bone or what? Is that a big problem if I skip that part?

the empty is another object (shift+A then empty and here I have chosen a sphere shape). Empties are usefull as they are not rendered, so they can be pivot points, constraints, anything... that can be used to help articulating constraints or other (you can find it easily I guess in the blend file uploaded for the answer)

And so, to be clear here "empty" does not mean "nothing" but effectively an object of type "empty"

Okay, I'm stuck.
The gun is following the right hand but the empty isn't following the gun externity (GripLeft), so the left hand isn't following the empty neither. I did everything step by step, only missed one part, I guess. The gun isn't parented to its armature, because I do not know how to parent it with the weights only on the root.

In some cases you may need to "update" these constraints going in pose mode. For the gun, parent it with empty groups, go to edit mode, select all vertices then in the property panel select the root bone and click assign. Concerning the empty, have you set the constraint of the fourth image after the gif above ? If I can suggest : have a look at the blend file I have shared before doing it on your model. Disable some constraints and see the result

Yes, I did set it. Under the externity you mean the bone on the very end of the gun armature, which is held by the left hand? If so, I did it correctly.

Let us continue this discussion in chat.


text:
Make imported images insensitive to lighting but cast and receive shadows
I'm trying to do a cutout animation with imported .png's. The only way I've found to get them to render faithfully is to make them either shadeless or emitters with an emit value of 1. However, I'd like to simulate the effect of actual cutouts where they sit on top of one another and cast a small drop shadow. I've tried adding a second lamp with the 'only shadow' shadow checked, which works to some extent, but the shadow is very faint no matter how much I increase the energy of the lamp.
Is there any way to achieve this effect?

Well you see, in reality, shadow is simply the absence of light. So to make something shadeless and receive shadows doesn't make any sense at all.
But of course, there is always a way around the laws of physics :)
There may be a few ways to do this, but the first that comes to mind is compositing:

Your "shadeless" material should just be a regular material with shadeless turned off.
Then you need to give a unique Object Index (or Material index) for the objects with shadeless materials - this will allow to do compositing for only those objects:

Then enable some render passes:

Shadow to give you... well, shadows.
Object Index so that you can isolate those shadeless objects.
Color so that you get the material color without any shading.

So when you render, you'll get:
Plain uncomposited render:

Shadow:

Object Index:

Color:

Then in the node editor, you simply need to multiply the Color and Shadow passes to get your shadeless but with a shadow effect:

And then use the ID Mask node to isolate the objects that you want to be shadeless, and use that as the Fac to mix the raw render and the shadeless part together (so that only the objects that you want to be shadeless are shadeless):

Download the .blend

Note: If you get aliasing issues, enable Full Sample in the render settings.

Thank you for such a comprehensive answer. I'm very new to Blender so this looks quite intimidating (although the result looks like exactly what I'm looking for). If you don't mind, I'll see if there are any simpler solutions offered before accepting it as the answer.

I like Greg's answer a lot. That said, if you want a method that doesn't involve compositing you can always use textured planes with transparency and give it nice even lighting with a Sun Lamp.
Final Result

How-To
To get your textured planes in to Blender the easiest way is with the Import Images As Planes add-on, which is included with Blender so it's as easy as enabling in your Preferences.

You can then add your cut-out images from the File Menu.

The add-on includes some handy preset options. You'll want to check "Use Alpha" and select "Diffuse & Transparent". You can choose between Straight Alpha and Premultiplied Alpha.

Add a Sun Lamp, which is a type of lamp that lights from one direction evenly as if coming from a gigantic light source like the sun. The Sun Lamp's Strength determines how bright the lighting is, and its Size determines how soft or hard your shadows will be. The distance from one plane to the next is also a factor, as you can imagine.

Aim the Sun Lamp almost directly facing your image planes, with enough rotation to create a shadow in the direction you desire.

Another great answer. I'll give them both a try. Thank you.


text:
how do I make already drawn grease pencil lines all the same thickness?
I've been working on creating an animation of myself. I built the final version from my early composite sketches. can I do anything I can do if I don't want to have to try and hand edit to get consistent line weight.

Use a Thickness Modifier with Uniform Thickness enabled. You may also benefit from a Smooth Modifier, but to be honest, it's been a while since I 've used it and I can't seem to get it to do what I want it to do. Maybe you'll have more luck:

NOTE - I figured out why I couldn't get it working like before - the smooth should be above the thickness in the modifier stack. You don't need a high strength for it, but it can smooth out some minor inconsistencies before the lines get thickened (like in the eyebrows), making the end result look slightly better.

I'm having a hard time deciding on a sketchy or more smooth style. that will be a cool non-destructive way to play around.

worked perfectly. thank you.


text:
I didn't press Alt to smooth when creating edge loops is this fixable?
so I was watching a tutorial for making a hard surface airplane, only after a long time did I notice the presenter was selecting the edge loop, pressing alt then dragging it, which apparently is different than just dragging it.  so now my model is more jaggy. Can I reapply that effect to a loop?

Are you sure the lesson author didn't press G twice after selecting a loop?  So It could be useful to know what exactly was done in the lesson (it may be eaiser to provide a link with time mentioning). Regarding to Alt - it is pressed to select adjacent loop instead of one edge/vertex/face.


text:
How do I finish cutting out this wheel well?
So I've been studying shrinkwrap modifiers, I created a forming block, the shap I want to "shrinkwrap" to, I created the basic car form over it, cut out some doors by removing faces, now I'm trying to create a wheel well. I watched a video where they did something using another shrinkwrap set to project.. i'm really close, my circle is "shrinkwrapped" to the cars surface, but I can't "cut it out"....

did you join the objects?

yes. I did join them the circle is part of the mesh? in edit mode, its just not connected?

I definitely remember in the video I saw, joining was an important part before the cut was made.

hmm maybe you should aply the shrinkwrap?

I would suggest the Knife Project command.

Basically you choose the cutting object, than the object to cut, enter in edit mode, put the camera perpendicular to the projection plane (if the object is shrinkwrapped you just have to avoid to make all the cutting geometry to be visible from the cam) and run the command.
It will also automatically select the inner faces of the cutting loop.

Another could be to use boolean operations.
From the cutting profile you have to create some faces and extrude them just of the amount needed to penetrate the object to cut. Than apply Boolean modifier set to Difference

Once applied, you should have the faces that belonged to the cutting object extrusion selected, ready to be deleted.

I'd really be interested a different way. that leaves me with jaggy edges, really bad.


text:
png resolution is wrong when opening file from the UV/Image Editor
I was sent an png for a texture by a friend.
The image is 192 x 24 pixels

it's properties are correct in windows explorer when I view the downloaded file, but as soon as I open it in blender...it's y pixels are halved so it's very much blender. but I don't know why.
If I use the blender Image Editor and Alt+S to save the image again, the original is converted to 192 x 12 (Which is half the y)

You need to Uncheck the Fields checkbox

Care to add some more information to your answer? :)


text:
How do I make the upholstry of a vehicle panel looked puckered by a door handle?
Simples.
I just want to create a depression in the panel, as if it was made of leather and the door handle was installed against it.

Here's the best example I could find. Note how the panel around the hardware with the red thing hanging out has caused a depression.  I tried to create more loops and add an inset area on the panel, but that caused the panel to act weird due to my subsurf modifier. I'm hoping there is some deform that will "push in" based on another object

see this http://blender.stackexchange.com/questions/33932/physical-interaction-between-objects

Dynamic paint with brush=door handle using proximity and canvas=panel as displacement?

Hmm, I need to find a better picture, the surface bulges out as a result of the displacement

As example, my monkey is the door handle, and my cube is the door panel.

Use for both a subsurf modifier.
Overlap the monkey with the cube
Enable the cube as canvas and set type to displacement

Enable the monkey as brush and set paint source to mesh volume


text:
Smoke is not appearing in cycles, neither is the CPU option
I have v2.75 and I keep seeing that I need to change the render to CPU, but I don't even see the option... How do I fix this so that I can see the smoke when I render it?

v2.75.4 to be specific.

CPU is the default, so if your smoke isn't rendering it's likely for a different reason. If the answer cegaton linked doesn't solve your issue, perhaps if you could upload your .blend we might determine what the cause is

The CPU/GPU dropdown selection menu is not visible because you don't have an Nvidia GPU card enabled for usage (either your card isn't Nvidia or it's not enabled for rendering) in the user settings. CPU mode is the default render mode in this case.
If you DO have an Nvidia card installed, you may have to update to the newest drivers for it to show up in your CUDA user preferences selection.


text:
Eye in object mode
Hello i imported a base mesh from blender swap and have been editing it.But im making eyes and when im in edit mode they move fine.But when i veiw them in object mode they warp all over, they look like deforming water balls as i move them to fit better in the face.Can yo please help.
Also the x topology so that when you edit one side the other moves exactly the same dose not work all that well neither.

are you using modifiers on the eye?

The screenshots of the model in Object & Edit mode and mesh properties (like Modifiers and Object data tabs' contents) illustrating the problem would be very helpful. In addition you can include .blend file (or a part of it) in the question.


text:
Exporting Parts of mesh
Hello is there anyway to export parts of a mesh only and not the whole thing.For example.I have a chest piece that is made on one character mesh.I can duplicate that chest piece off of that mesh.But I want to export that chest piece only,for another character in a totally different file.How can I do that, please help?.And I like to thank you.

Afaik no, but it could also depend on the specific exporter, since they are all independent (made differently).
eg: the collada exporter has a specific option.

The simplest way to get what you need is to save your file, then create a new empty blend file and import in it from the saved file where you have only what you want (eg chest piece).
Then, even without saving the new file, export from that new file to th eformat you need (eg: obj, dxf, fbx, etc.).

yes there is a way, first make another (save as) of your project so you can work on it without loosing it while doing the way i will talk about, then select every thing you DON'T WANT to export and delete it, then export the rest of it, it must be done this way ;-)


text:
Pose only saving some bone transformations in pose library
I am trying to add new poses into my pose library for a butterfly rig. The rig operates as expected, and all the bones can be key-framed for animation. However, when I try and save a pose into the pose library, it is only saving the transformations on some bones. Specifically, it is not saving the location, rotation, or scale on any of the wing bones or the main root bone, only the location of the IK handles for the legs.
Is there any sort of common cause for such an issue and does anyone have any experience fixing it? I have encountered it in other scene files, and often brute force/saving/reloading/selecting everything when adding pose would often accidentally fix it to a usable degree (eventually), but in this instance, nothing is working.

The pose is only saved for selected bones. Did you select everything before saving?


text:
Synchronizing object in Cycles
I have a model of a butterfly that uses a displacement map for most of the detail on the mesh at render time. To get an accurate render, I have it subdividing 4 times for the render before applying the displacement map.
While it gives me great detail, the downside is that I then have to wait a while for it to start rendering as it goes through a long "synchronizing object" stage on every frame. I'm assuming this is when it calculates the displacement on the object? I'm not entirely sure what this is doing.
Is there a way to bake this information or get around this step without spending so much time on it? This project has potentially quite a few frames to render at 1080p, so any way to lessen that is welcome.

Maybe the new Open SubDiv will increase the render performance and reduce the calculation time. http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.76/OpenSubdiv

This BA thread is basically talking about the same thing, not that there is much of an answer there.


text:
How to disable AO on smooth edges, but keep it enabled on sharp edges?
I'm creating a scene, and I really like to use AO, because it adds some bonus detail to the final render. But in most of the cases it ruins the smooth feeling for smooth edges. I have marked sharp edges everywhere, where I wanted sharp edges, to make sure they will look just cool, and the AO looks good on them, not like on smooth edges. I'll attach a few examples:

Adding an EdgeSplit modifier before a Subdivision Surface instead of doing autosmooth seems to alleviate the problem. Dirty, I know...

Is there any way to make it without increasing the poly-count? Subdividing everything wouldn't be too good for me.

I know, but I didn't find another way. You could of course always switch to cycles, which doesn't have this issue.

If I switch to cycles, do I have to re-do everything to make it look as it did in default Blender, except the AO?

If by everything you mean the materials, yes. Modelling stays the same. You can try it, it's not destructive, and see what you lose.


text:
Weird rigged object deform

First of all, I am aware of the issue here, which is that the Automatic Weights couldn't really figure out how to handle the object, that has separate meshes (shoelaces and its rings).
My question:
Is there a quick and easy solution for this, or I am doomed to paint it by hand?
My problem with hand painting is that I'm the wrong kind of precise, who either makes it full red or full blue, which isn't really good, yet it takes ages. That's why I'm looking for a 2-click, automatic solution or something like that.
I tried Boolean Union to merge them into one mesh, but let's just say I wasn't satisfied with the results and it looked even worse in pose mode.
Possible solution, that I don't know how to do:
Is it possible to have the boots follow a simple dummy mesh, that is parented to the armature instead of the boots?

You should be able to fix that in Weight Paint mode, but as you suggest with your "dummy mesh" you could use a trick like Mesh Deform modifier, as I explain here: https://blender.stackexchange.com/questions/120954/mesh-not-following-armature

The dummy method worked like a charm. Thank you!

I would make a quick (manifold) cage for the model, autoweight that, and then data transfer weights onto my boots.


text:
Bmesh.ops.mesh_to_bmesh usage returns cryptic error
I was messing around with bmesh and tried to use the mesh_to_bmesh operation, however, I was returned this error...
NotImplementedError: mesh_to_bmesh: keyword "mesh" type 4 not working yet!

The best I can tell this is saying that the function hasn't actually been implemented into the code and is just a placeholder. If this is correct, can anybody tell me if there is another way to transfer a mesh back into a bmesh object? Thanks.

have you tried bmesh.from_mesh(mesh)

@Chebhou Just did and that did the trick. Thanks.

The proper function to be used is the  bm.from_mesh(me) function where bm is the bmesh object being transferred to and me is the mesh. Also for the reverse operation we can use bm.to_mesh(me) which will load the bmesh data back into the mesh.
For code example see the template bmesh_simple.py which is included in blender text editor.

some of the bmesh operation didn't work yet like bmesh.ops.bmesh_to_mesh , mesh.ops.mesh_to_bmesh and bmesh.ops.object_load_bmesh, the only note is that the DOC says :

this bmop is private


text:
Limited rotation?

I can't seem to rotate the highlighted part, if I try to do so with R it will rotate the whole object.
Can someone tell me a way to only rotate the highlighted part?
(Also thanks for the helpful replies on my previous question!)

You have proportional editing enabled, the icon with the blue circle on the bottom of 3D view screen

You have to turn off Proportional Editing, just press O key.


text:
What's the correct way of implementing dynamic dropdown menus in Python?
First time bpy user here.. working on a small automated pipeline. Most of it is already in place, including a database and a PHP framework that provides data for use by the Python code below.
My intent in this particular part is to download JSON lists of projects, asset types, assets, tasks and task statuses, and to load them into dropdown lists inside Blender. Selecting the appropriate values in these dropdowns then saves the file into the correct directory.
The code I'm posting here is a mixture of a variety of answers to questions much like this one. However, none of it seems to work as my dropdown lists simply don't show up. There are no errors, but also no dropdowns. From what I've seen, there seem to be quite a few ways to do this, but I can't figure out what exactly I'm doing wrong or what is the generally accepted way of accomplishing this.
# Imports
import bpy, requests
from bpy.types import Panel, Operator
from bpy.props import EnumProperty

base_url = "http://my.fancy.base.url/"

bl_info = {
    "name": "Pipeline",
    "description": "Asset management for Blender",
    "author": "Sam",
    "version": (1, 0),
    "blender": (2, 75, 0),
    "location": "File Browser",
    "category": "System"
}

class FILEBROWSER_PT_Pipeline(Panel):

    bl_space_type = 'FILE_BROWSER'
    bl_region_type = 'TOOLS'
    bl_label = "Asset management"
    bl_category = "Pipeline tools"

    def draw(self, context):
        l = self.layout
        # Draw project dropdown
        r = l.row(align = True)
        r.prop(context.scene, "PL_Project")
        # Draw type dropdown
        r = l.row(align = True)
        r.prop(context.scene, "PL_Type")
        # Draw asset dropdown
        r = l.row(align = True)
        r.prop(context.scene, "PL_Asset")
        # Draw task dropdown
        r = l.row(align = True)
        r.prop(context.scene, "PL_Task")
        # Draw status dropdown
        r = l.row(align = True)
        r.prop(context.scene, "PL_Status")

# Callbacks for dropdown changes

def change_project_list(self, context):
    return [(p['p_project'], p['project_reference'], p['project_name']) for p in bpy.data.scenes["Scene"].PL_Project_List]

def change_type_list(self, context):
    return [(ty['p_type'], ty['type_reference'], ty['type_name']) for ty in bpy.data.scenes["Scene"].PL_Type_List]

def change_asset_list(self, context):
    return [(a['p_asset'], a['asset_reference'], a['asset_name']) for a in bpy.data.scenes["Scene"].PL_Asset_List]

def change_task_list(self, context):
    return [(ta['p_task'], ta['task_reference'], ta['task_name']) for ta in bpy.data.scenes["Scene"].PL_Task_List]

def change_status_list(self, context):
    return [(s['p_status'], s['status_reference'], s['status_name']) for s in bpy.data.scenes["Scene"].PL_Status_List]

# Registration

def register():
    bpy.utils.register_module(__name__)

def unregister():
    bpy.utils.unregister_module(__name__)

# Let's go

if __name__ == "__main__":
    register()
    # Download lists
    bpy.data.scenes["Scene"].PL_Project_List = requests.get(base_url + "tool/get-projects").json()
    bpy.data.scenes["Scene"].PL_Type_List = requests.get(base_url + "tool/get-types/" + bpy.data.scenes["Scene"].PL_Project).json()
    bpy.data.scenes["Scene"].PL_Asset_List = requests.get(base_url + "tool/get-assets/" + bpy.data.scenes["Scene"].PL_Project + "/" + bpy.types.Scene.PL_Type).json()
    bpy.data.scenes["Scene"].PL_Task_List = requests.get(base_url + "tool/get-tasks/" + bpy.data.scenes["Scene"].PL_Asset).json()
    bpy.data.scenes["Scene"].PL_Status_List = requests.get(base_url + "tool/get-statuses").json()
    # Create dropdowns with update callbacks
    bpy.types.Scene.PL_Project = EnumProperty(items = change_project_list, name = "Project")
    bpy.types.Scene.PL_Type = EnumProperty(items = change_type_list, name = "Type")
    bpy.types.Scene.PL_Asset = EnumProperty(items = change_asset_list, name = "Asset")
    bpy.types.Scene.PL_Task = EnumProperty(items = change_task_list, name = "Task")
    bpy.types.Scene.PL_Status = EnumProperty(items = change_status_list, name = "Status")

If this was a proper addon register() would get called before blender's bpy.data is fully ready. you might get a _RestrictData error in that case. -- but as you are running this from TextEditor and bpy.data is already present, something else is going on. I'd do a print statement to see the value of `.PL_Status_List at various points , it might not be filled with what you think..

That's an interesting answer, as I did get a _RestrictData error until I put all the downloading and list generating code in the if block behind the register() function. I'm not running this from the text editor, I reinstall the script every time I want to test it. But I tried it, and the Text Editor says "Python script fail, look in the console for now..." - the console doesn't say anything, but when I try to create PL_Project_List myself there, all I get is "'Scene' object has no attribute 'PL_Project_List'" ..

related: http://blender.stackexchange.com/questions/10910/dynamic-enumproperty-by-type-of-selection

The two main problems with your script are

you are assigning to bpy.data.* in the register function, that won't be allowed when the add-on's register() is called on startup
the content of bpy.data.scenes["Scene"].PL_Project_List isn't what you expect. See the python console..  (if you can't assign something via console, it's not likely to work in a script)
code:
>>> bpy.data.scenes["Scene"].PL_Project_List = 'yello'
Traceback (most recent call last):
  File "<blender_console>", line 1, in <module>
  AttributeError: 'Scene' object has no attribute 'PL_Project_List'

# this would work (called an ID property) but it has a limited
# range of acceptable data types (it must be stringifyable)
# _and_ you still can't do this in register + startup
>>> bpy.data.scenes["Scene"]['PL_Project_List'] = 'yello'
>>> bpy.data.scenes["Scene"]['PL_Project_List']
'yello'

RNA props vs ID props

I've reduced this to what I think is the core of the problem. If it doesn't work for one, it won't work for any. There's nothing stopping you from using Python dicts as Cache objects.
# Imports
import bpy
import requests
from bpy.types import Panel, Operator
from bpy.props import EnumProperty

def fake_request():
    return [{'p_project': str(i), 'project_reference': str(i**2), 'project_name': str((i**2 / 2))} for i in range(3)]

# think of it as a cache dict / list
PL_Project_List = {}

class FILEBROWSER_PT_Pipeline(Panel):

    bl_space_type = 'FILE_BROWSER'
    bl_region_type = 'TOOLS'
    bl_label = "Asset management"
    bl_category = "Pipeline tools"

    def draw(self, context):
        l = self.layout
        r = l.row(align=True)
        r.prop(context.scene, "PL_Project")

def change_project_list(self, context):
    return [(p['p_project'], p['project_reference'], p['project_name']) for p in PL_Project_List['projects']]

def register():
    PL_Project_List['projects'] = fake_request()
    bpy.types.Scene.PL_Project = EnumProperty(items=change_project_list, name="Project")
    bpy.utils.register_module(__name__)

def unregister():
    bpy.utils.unregister_module(__name__)
    del bpy.types.Scene.PL_Project

if __name__ == "__main__":
    register()

This part is only really useful for the development stage, and running the addon from TextEditor after hitting F8 a few times to clear the Python added stuff.
if __name__ == "__main__":
    register()
    ...

If it's running as an addon, but you aren't testing from TextEditor it's still not a good idea to rely on this construct of if __name__ == "__main__" to populate the data structures.

But how do I populate my lists?

Either have a button on the layout to 'populate lists', or 'update lists' (people like updates!)
Or populate an object like a Dictionary as a cache object (shown above, this PL_Project_List is a dict, so maybe that's a bad name.. I'd settle for PL_Project_Cache -- this object is local to this file only, unless the file is imported by some other file, it's not strictly a 'global' )
Or investigate how to store the info in a CollectionProperty / PropertyGroup ( good reference is here : How can I store and retrieve a custom list in a blend file? )
Or if you are comfortable stringifying your incoming data (i expect the database information to be lightweight.. not 100mb of lists..)
code:
>>> bpy.types.Scene.PL_Project_List = bpy.props.StringProperty()
>>> bpy.types.Scene.PL_Project_List = 'yello'
>>> bpy.types.Scene.PL_Project_List
'yello'

This is looking promising, thanks very much. When I get home tonight I'm definitely trying this out.

have updated for completeness, i'm almost certain people will have additional views on the matter.

this is working like a charm, thanks very much! looking into that update button thingy for populating my data now, thanks again!


text:
Planar UV Mapping?
Is there a way to do Planar UV mapping that maps front and back side into separate UV islands? In a way that the front side islands are on the left half of the UV map and the back side islands are on the right half of the UV map? The Project From View maps both sides into one island in the center of the UV map.
I'm looking to make simple retro styled UV maps, like in Quake1 and 2.

You don't need to create the separate UV islands for each texture. You may unwrap once and assign two textures to one mesh (to both sides of it) using nodes. Set them up as pictured below.

Result.

@TwinBeast I'm not sure if I fully got the idea of what you want to achieve. If it isn't what you want, please tell me and I'll delete this answer.

Interesting, never thought about using projected UV this way. And the result is so realistic! :)

@Bithur Yeah, the next gen graphics ;).

There can be only one texture displayed on a model in the MDL format used by Quake1 engines. For now I used Solid display in the ortho view, then select the faces, UV them, move them a bit in the UV editor, then invert face selection and UV the rest, then position the UVs. Just wanted to know if I could select the whole model and get the same result with one press of a button.


text:
Exporting Animation with Modifier
I have a cube that moves along a bezier curve (it's a mine cart). It is a simple animation, keyframe at start, keyframe at end, with a curve modifier on the cube.
I want to export the animation and load it into Unity to test some stuff out. However, when I do that, the animation exports, but there is no curve modifier - it just travels along a straight axis, instead of along the curve.
Anyway to fix this?

Are you sure you do not mean to do a Curve Path Animation ?  A Curve Modifier is a deform modifier to change the shape.... I just tried a Curve Path Animation (set parent to -> Follow path)  and it comes fine in Unity

Have you tried baking the animation to the cube, then importing it?

Like oenvoyage (in the comments) I'm not sure a curve modifier is what you're talking about either. For a "simple" "mine cart" animation on a curve I would think you would use something like a "Follow Path" constraint.
If you are using an actual curve modifier my solution here will probably not work.
But if it's simple object animation created using a constraint like I theorized you might use, or parenting or any other similar methods of animating that is not just simple keyframe animation you can always bake the action to keyframes so it should always export no matter what the destination program's compatibility or incompatibility with constraints.
With the object selected go to "Object/Animation/Bake Action"

In the new menu you will probably at least want to select "Visual Keying" which will make it bake (AKA turn into regular keyframes) all animation, like constraints and parenting. If you have constraints or a parent animating the object you can check the options to "Clear constraints" and "Clear parents," or just remove the parenting/constraints yourself when you're done. You also want to make sure the frame range selected encompasses your entire animation length.

This will take most any animation or movement and convert it into keyframes on the location/rotation/scale of the base object, so it should be reasonably simple to export it to any other application like Unity. However, you will lose all the control and ability to adjust the animation that non-destructive constraints and parenting offer you.

Try the following:
1.) Add Constraint Follow Path
2.) Animate Constraint
3.) Press Alt + G to clear the Location (That could solve your Problem)
4.) Bake animation


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Is there a way to output gif animation from blender?
Is there a way to output an animation or video file in gif format from blender?
If not, what about VSE? Or can I record a screen inside blender?
Thanks a lot.


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Can 2 sets of parented objects be added to a 3rd parent?
I'm new to Blender and I'm trying to organize my objects by creating a parenting hierarchy.
I currently have two parented sets of objects each containing several dozen objects (children) each. I would like to combine these two parents under a "super" parent while retaining the "sub" parents. Is this possible?
I've been unable to do this myself, however my research so far says nothing about this being impossible.
Thanks.

Yes, this is possible.
Just select the parents of each individual set of parented objects and parent them to another object.  Note: it is often good practice to use empties as parents for sets of objects for this kind of application.

It works! Thanks for the response PGmath! I realize my mistake was that I was hitting the P key for parenting the empties instead of Ctrl+P. Thanks again!

@WilburPost  Glad I could help!  To mark this as solved you can accept this answer by clicking the green check-mark next to the answer.


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How can I create a soft outer atmosphere that fades into space?
I'm creating an animation that simulates orbiting a planet. I'm having success on all fronts except for one: How can I create a soft (blurry) atmosphere that fades into space?
For static images this is easily accomplished post-render in Photoshop, but how to do it for an animation?
The outer atmosphere also needs to realistically interact with light.
I've done a lot of research and tried a lot of ideas, but no joy. I did find a 3rd-party payware solution that uses an emissive material that achieves a nice soft effect, but because the material is emissive and the animation includes the parts of the planet in shadow, I can't use it globally. Any suggestions? Thanks! Blender 3.1.2, Windows 11

I think my second answer -- using a Gas Domain -- is what you're looking for.

Try using a combination of Volume Absorption and Volume Scatter nodes into a Mix Shader, into the Volume material output. Vary the Density on the two Volume nodes.

My trivial example:
As rendered in Cycles:

Thank you for the suggestion and for the example! It appears your solution uses Eevee, and I'm rendering in Cycles; in the latter the effect renders opaque black. I'll need to play with it to see if it's the solution I'm looking for. Thanks again.

@WilburPost I just downloaded the solution and rendered in Cycles -- looks good to me and I added that rendering to the bottom of my answer.  But it looks clear that it doesn't "fade into space".  I'm thinking you may have to use geometry nodes.

Here's another solution that appears to meet your criteria of "fading" as you render further away from the planets surface.
  (after downloading be sure to Bake the domain).
For the planet:  Object >> Quick Effects >> Gas
I use a gas simulation that 1) only simulates for a single frame, so the atmosphere is relatively "static", 2) does not use the Scene gravity (you might add a Force object colocated with the planet sourcing the gas):

You can then play around with the material that is automatically added (Principled Volume).  I adjusted the Color to pure white, reduced the Density multiplier, which is based on the density attribute of the gas particles per voxel.

The render (here in cycles) seems to have the effect you are asking.   I would fuss with other simulation and render parameters to get more realism and thinner atmosphere.  An example might be to reduce Buoyancy Density to less than 1.0, perhaps to 0.1.


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Blender Asset Browser: Change which side of object is previewed?
I'm really enjoying organizing my Blender assets via the Blender Asset Browser. One unfortunate thing is that when generating previews of objects, the Asset Browser tends to generate previews of the backs, i.e., least interesting sides of the objects. (See screenshot).
Is there something I can change in how the Asset Browser generates previews?
or
Is there something I can change about the geometry of the objects so that the previews are more informative?
Thanks. Blender 3.1.2, Windows 11

Currently it seems that it is hardcoded to take the thumbnail of the object from - global Y axis, slightly rotated towards +X and +Z. So you either have to rotate every object 180° along global Z axis and apply the rotation after setting the origin point to individual origins (which will mess up your files if these objects are already used as links), or render custom previews and select them afterwards, which will be very time consuming

Thank you for the response. This is what I thought. As the Assets Browser is a work in progress I'll hold and see if the Blender folks address this.

As far as I know this is in the works. I think users will be able to choose custom scenes to render their assets


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Why do I have Blender 3.1 in AppData Roaming when it has not been installed yet?
I am preparing to install an update to an existing add-on and the creator recommends that I bypass Blender and use the OS to install the update directly to the \AppData\Roaming\Blender Foundation\Blender folder. Okay, however, I see two versions of Blender there: 3.0 and 3.1, both of which have \scripts\addons subfolders with all of my add-ons. What's weird is that I have not installed Blender 3.1 yet, so why the 3.1 folder? And why two sets of add-ons taking up space on my HD? Thanks.

Have you ever launched the beta 3.1 version ?

@Gorgious, it could be because I installed the beta version of K-Cycles 3.1, but the folder creation dates didn't correspond. Now that I have Blender 3.1 installed all of my add-ons are now pointing to 3.1. Thank you!


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Is Time Stretching the same as Time Remapping?
I have a 1400 frame animation at 30 fps and I want to change it to 60 fps while maintaining the relative placement of keyframes. I found a 2021 video that shows how to use the Time Remapping options in the Output Properties, but when I look in my Blender version I see instead Time Stretching. Are they the same thing? By the way, changing values in Time Stretching doesn't appear to accomplish the same thing as that demonstrated with Time Remapping in the video. Thanks. Blender 3.10, Windows 11

It's the same, different name

It's like a Speed/Duration thing yes. Doesn't allow for the granularity you get in Time Remapping, just stretches your keys out. Set your time stretch to 200 and you'll have the desired 30 to 60fps result.
Alternatively you can find a way to select all the keys in your scene, take your playhead to the start of your animation and then scale it up by 2x ( S,  2,  Enter), and then change your render settings to 60fps.