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Fixing undefined shader nodes
I am using blender 3.0.0 and i have many shader trees on objects with undefined mix RGB nodes, is there a script or any other way to revers to the original nodes state on multiply objects?

Suggestion.  Please include a screen capture of some relevant Blender UI.  Please try to edit your writing to be more clear.

The word [undefined] seems to be spelled in two different ways in your writing.  The title seems incorrect.

Are you trying to load files made in a much earlier version of blender (pre-2.83)?

You're probably loading a .blend from a newer version of Blender. Easiest thing to do is just update your Blender. You could try writing a script to guess what the node should be from the input/output socket names but I don't think you can get what eg. the mode on Mix nodes should be. But really, just update Blender.

@Christopher Bennett,Thanks, This is a file i have opened before in version 3.0 and never had this problem. I am not vey good at scripting.

@scurest,Thanks, I have already tried all stable versions all the same problem.

@atomicbezierslinger, Thanks spelling corrected.

@digitvisions Did you try the latest alpha?

@scurest, this is a production project file the alpha is not a stable version.

For another question I made a script that should theoretically be able to replace undefined Mix nodes in one click. It really works only on Mix nodes, typically as you get undefined ones when opening a file made on ≤3.4 into a Blender <3.4.
It will not recover the mix type nor input values. It will only preserve the old socket connections.
import bpy

for material in bpy.data.materials:
    if not material.use_nodes:
        continue

    node_tree = material.node_tree
    nodes = node_tree.nodes

    fail_state = False

    for node in nodes:
        if node.name == "Mix":
            try:
                input_links = {}
                output_link = None

                if len(node.inputs) > 0 and node.inputs[0].is_linked:  # Factor input
                    input_links[0] = node.inputs[0].links[0].from_socket
                if len(node.inputs) > 6 and node.inputs[6].is_linked:  # Color1 input
                    input_links[6] = node.inputs[6].links[0].from_socket
                if len(node.inputs) > 7 and node.inputs[7].is_linked:  # Color2 input
                    input_links[7] = node.inputs[7].links[0].from_socket

                if len(node.outputs) > 0 and node.outputs[2].is_linked:
                    output_link = node.outputs[2].links[0].to_socket

                mix_rgb_node = nodes.new(type="ShaderNodeMixRGB")
                mix_rgb_node.location = node.location
                mix_rgb_node.blend_type = 'MIX'

                if 0 in input_links:
                    node_tree.links.new(input_links[0], mix_rgb_node.inputs[0])  # Factor input
                if 6 in input_links:
                    node_tree.links.new(input_links[6], mix_rgb_node.inputs[1])  # Color1 input
                if 7 in input_links:
                    node_tree.links.new(input_links[7], mix_rgb_node.inputs[2])  # Color2 input

                # Reconnect the output link to the new MixRGB node's Color output
                if output_link:
                    node_tree.links.new(mix_rgb_node.outputs[0], output_link)

                nodes.remove(node)
            except:
                print(f"failed on material '{material.name}'")
                fail_state = True

print(f"Replacement of 'Mix' nodes with 'MixRGB' nodes completed {'with errors' if fail_state else 'with no errors'}.")

Paste in text editor and run.


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transparent shader going black
I've searched for solution all around the internet but nothing seems to help.
In my project some of the bubbles always render as black blob. I know its related to not enough rays exiting the object.
Problem may be within the shader as different one renders properly. Any ideas?

[edited - I added the meterial nodes screenshots and a blend file]

Hard to say, without your file ...

what are the 3 images? are you sure that it's not because of the world color or hdri?

Here it is a tutorial: https://www.youtube.com/watch?v=10NWElFmZms

@vklidu how to ad a .blend file here?

@moonboots world color strenght is set to 0 no hdri here

@diniulian thanks but I already watched this and it didnt helped me

@REFLEX Share file via https://blend-exchange.com copy given code and place into your Q (via Edit).

@vklidu done, if your willing to take a look at it and share your insights I will be grateful

Partly it could be an issue of intersecting spheres. Partly I don't know ... So here is just some trick used to avoid glass darkening by affecting transparency by Ray Dept light path ...
Your shader ...

The trick addition ... from here ... just be sure Render Properties > Light Path > Transmission and Transparency is set like 12 ...

thanks a lot, I tried this technique also mentioned above in youtube video but somehow I was doing this wrong the whole time. case closed, thanks to everyone :)

source: Stack Exchange

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

sort: votes


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Recover a file that cant be opened
I was making a blender project using geometry nodes and after tried to scatter some grass around, it crashed. Now of course I hadnt saved before doing that and the backup autosave that blender made is from after the edit that caused the crash. Is there any way I can recover this or do i just have to redo it? EDIT: the crash was probably from too much density.

Hello and welcome. yes you have to redo it.

You don't say what OS you are using, but if it's Windows you could try typing '%temp%' (without the quotes) into the Windows search field. This should open the Windows Temp folder and you might find some earlier autosave files there to get you out of trouble.

@BlueJay987, you can try to open a new blend file and try appending the node from "crashed blender autosaved file". But if the issue is because of density of the mesh generated by Geometry node, then once you attach the node network to a mesh, it may crash again.

@ChristopherBennett The Cache folder just has an asset-library-indices folder in it here. The autosave files are in the Temp folder here as I indicated above.

File -> Recover -> Auto Save

Like suggested in the comments, your best bet is to make a new file and attempt to append your objects or node groups from the problematic autosave. That's File->Append:

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


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How to bend painting frame sections in hollow?
I am modeling a  picture frame. I would like to have a rounded profile instead of a straight one.
I divided  faces than I want to bend with loop cut tool. but I have no idea.

You could use a custom bevel profile.
I started with a cube, inset the front and back face, and bridged the edge loops to create a frame.

Select one edge loop and create a bevel with Ctrl + B.
Once you create a bevel, you can open the panel in the bottom left to modify your last action.  Bump up the number of segments and select Custom profile.  You can model your bevel using the curve provided.

You could create a right angle and bevel it with CtrlB (the options are in the Operator box):

If you have already given your angle a bevel like this one:

You can select a central edge, enable the Proportional Editing option, choose its Smooth falloff option, make sure that the radius is small enough (mouse scroll wheel) and move the edge on the X axis:

Here I give an answer that might also help for this kind of object.

"You could move one of your edge loops with the Proportional Editing option enabled" I need more help for this solution

I select a loop with edges selected and o shortcut

please share your current file: https://blend-exchange.giantcowfilms.com/

I did it. You will find the link on my post

I've edited my answer, I hope it's clear

clear but not for me. After loop cut. I select a central edge, I click on the circle on the top of the 3D view for proportionnal editing but it is all the frame that is moving !

yes because the influence radius is too high, you need to reduce it with the scroll wheel, when it will be small enough you'll see the radius circle

check here: https://blender.stackexchange.com/questions/7153/change-radius-for-proportional-editing#:~:text=You%20must%20press%20PgUp%20PgDown,%2C%20or%20Scale%20(%20S%20).&text=In%20the%20Redo%20panel%20located,to%20adjust%20the%20Proportional%20size.


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Image texture : how to only sculpt bright areas?
I am working on a painting fram based on image texture.
I want ot sculpt the bright areas to highlight them (corner leaves decoration) based on brightness How to sculpt bright areas?

use the image as a Reference or Background image and draw the shape with vertex extrusions. Also you need to decide if your ornement is an object or if it's part of the frame


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Lamp and eeevee volumetric light. How to avoid the halo around the light source
I am using volumetric light with Eevee and I have no idea to avoid the halo around the source of my light.

I can locate my cube with volume scatter under the lamp but I want to have volumetric light for my whole scene.
I changed start in volumetrics but I am not fully satisfied with the result.


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How to fix strange dimensions to real dimensions
I have an wall object with z = 2915m ! I can display this strange dimensions with scale cage.
When I reduce the scale cage, my wall is going to be very thin. How can I reduce the 2915m dimensions and keep my wall width.
Here is my file My file.

Not an answer, but to work in real measurements always apply scale. https://blender.stackexchange.com/questions/47318/why-do-the-measurements-of-this-object-seem-erroneous

I don't know how you managed to do that, but here's how to fix it:
Go into edit mode. Set the view mode to wireframe. Use box select to select the visible vertices, the ones that belong to the arc and you want to keep.
Press CTRL I to invert your selection
Press X and delete vertices.


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can we send vertex info to voronoi texture node to create texture
Can I use the vertices of a mesh as an input for site points of the voronoi cells (voronoi sites) to create a voronoi procedural texture with the Node Editor for the very same mesh?
I need something simpler (no extra features, no real time update necessary), but kinda similar like in this video, between 0:30 and 0:45.
https://youtu.be/Aljbw9PQlck?t=31
EDIT: The video is a bit misleading, cos it shows real time update, thought it would be nice (for easier edit) if possible but it isn't necessary. Main goal is a full control over the position of the cells.
The input mesh is suppose to be kinda a Delaunay-triangulation, except the 'triangulation' part, how the edges connect the vertices is not important only the vertices as site points for cells.

Unless you resort to do the computation manually for each point, then no, there no way to do that in Cycles. You can, however, do it in Animation Nodes using Vertex Colors, Screen Space Rasterization or UV Space Textures. I can show you how to do that, but it is not easy or convenient.

Since your linked example uses GLSL (OpenGL Shading language) a language designed to write shaders for real-time rendering, you should use OSL (Open Shading Language) which is very similar to GLSL, but it is designed for non-real-time rendering. You can write OSL into a script node.

@atevm How are you going to pass the points locations to OSL?

@atevm Thanks for the comment it was really helpful. Sorry for the misleading video. Non-real-time is okay for now, all I want is full control over the placement of the cells by adding vertices for a mesh, kinda as it shown in the video. The mesh should be the same one that get the generated texture or shader. I will check what I am able do with OSL. So, yes, Omar question is on the spot, but it sounds to me as a difficult topic.

@OmarAhmad Thanks for the advice. Is the Animation Nodes you mentioned an add-on? I found one with similar name before I post the question, also and other add-on: Sverchok. I will check what can I do with them. Also thanks for offering to help with AnimNodes.

Yes, Animation Nodes (AN) is an addon. Last year, I created something like this: https://i.imgur.com/7arUMVe.gifv It is a combination between manual points locations and random points location, so I can write an answer about the manual points location if you want.

ATM, Cycles/OSL still doesn't have the functions for using (read/write) pointclouds, and the only way to do this correctly is to have the points in a XML file. It's probably better to keep the points in some structured tree, for speeding up the queries.

@OmarAhmad I only programed GLSL, in that case you won't nedd pass the locations, since the fragment shader will receive the interpolated attribute values of the vertices.

@OmarAhmad Yes, please. What the gif shows is very close, if not exactly is what I am looking for. The small circle, that control the moved cell, is it the pointer for a 'snap to faces' feature?

Animation Nodes can be used to dynamically generate voronoi diagrams. Storing the color information of the diagram and accessing it from the render engine is a problem and our options are limited, one option is to use vertex colors, where the quality depends on the number of loops in the target mesh.
Vertex Color
First, you should study how vertex colors works in blender and how to assign it using Animation Nodes and Python. For this, you should see  my answer here. I will be using the Vertex Sample and Vertex Colors subprograms defined there in my node trees, so make sure you implement them first.
A simple F1 vornoi diagram based on random points can be generated using a KD tree as follows:

If one wants to use custom points locations, then one should replace the random locations with the custom locations:

If you want to have a solid color for each voronoi cell, then the indices output can be used or a random number based on it:

You might notice that the quality starts to become rather low, and that is the downside of using vertex colors, they are dependent of the loop count.

The other options we have are not any nicer, but they might be suitable for some cased.
Screen Space Tracing
What we can do is make a small render engine of our own that renders the vornoi as a fragment shader and use the output in the more advanced render engine. The render engine will cast a number of rays on the mesh defined by a BVH Tree, get the location on the surface point they hit, use it in the KD Tree, and then write the output colors to an image. To write an image given the greyscale value of each pixel, its width, height and name, a script like this can be used:
if imageName in bpy.data.images:
    image = bpy.data.images[imageName]
    image.generated_width = width
    image.generated_height = height
else:
    image = bpy.data.images.new(imageName, width, height)

image.pixels = [v for color in colors for v in [color]*4]

The ray casting part is simple, align a grid with the camera orientation and location, scale it based on the orthographic scale (3 in my case), we will perform an extra 90 degree rotation around the local z axis because the grid node returns the locations in the vertically first order while blender expects a horizontally first order, the node tree is as follows:

You may see the rendered image in near realtime in the UV image editor

Now, if I used the Windows texture coordinates (Screen Space Coordinates) with a material like this:

We will get the render projected on our object, which we can then use to do what ever we want:

I created this to work in orthographic view, I will let you create the perspective version on your own.

Other methods include UV space projection, it can be done as following. BVH ray cast is used to get the index of the polygon the ray intersect, we get the barycentric coordinates of the surface point through a barycentric interpolation, we get the UV space locations of the polygon's corresponding UV polygon, perform a convex combination using the barycentric coordinates we computed before, get the pixel nearest to the result of the convex combination or use some kind of interpolation like bilinear or bicubic, write the color to it. The resulted image can be used in the UV objects space as a normal texture. I shall not explain this method, because it doesn't really have any advantages and is hard and slow to implement.

Thanks!
I managed to reproduce the "Vertex Color" version. Still have questions.

I checked the link of your answer about vertex colors.  I still miss the part how to convert the distance floats to color vectors in the loop graph part of the graph. I made a simple one (LoopInput-GetListElement-mathMultiply-CombineVec-VecList), but I would like to know, how you did it.
Looks like, based on your gifs, when you move around the 'spherical empties', it happens in object mode. Why can I only see the cells when the interactionMode is VertexPaint and displayMode is Texture or Solid?

Ok, for the 2nd question I find a very short video:
link

@kca The Vertex Sampler Loop is exactly as you described, however, since the color a greyscale one, that is, all the vector components are the same, we can use the node Vector From Value to create the vectors. I guess you know the answer for the second question.

@OmarEmara, great works and I have missed seeing this. Minutes ago, I recognised YOUR style in this question and I knew it was you, before coming to seeing your name at the bottom. Thank you very for the nodes.

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


text:
What makes animation slow?
When working with blender, some models seem quite slow when animating.
What should look one for what generally slows down annimation?

shaders ??
subdivs ( most likely, but disabling doesnt always change a lot).
complex meta rigs ??
bone modifiers ??
alternate bone view types ??
???

My question is how to improve the animation speed, what should i look for and change.
Asking it as a more general question not related to a specific blend file.
Thus how is it possible to determine what slows down an animation.
To improve the rate of animation playback?

if the object is high-poly it will be hard to animate, is it the case?

it depends, are you refering to animation in solid mode or render preview? If we are talking only about the solid mode, then I can tell you that performance is based on how many vertices need to be moved from 1 place to another and your CPU has to calculate it... Due to this vertex count, subdiv are mostly the 1st to slow you down, in my case it is always subdiv or another modifier active on my object, other things never seem to slow it down

@moonboots, its not always the case i wondered what effects it. complex shaders ? or are certain modiefiers slow, does one needs to be aware of specific combinations.

I don't think there are special combinations, but the more complex the slower it gets. The framerate setting is very often not achieved in 3D Viewport playback if the scene is a little complex. To test motions of your animation in correct speed you should do viewport renders and playback the rendered frames with Ctrl+F11.

maybe complex shader if you are in Rendered mode, of course, but as MikoCG says Rendered mode is much slower, could you please share an object that you consider slow to animate?

@moonboots its a generic question not specific to a certain file

Maybe a better way to phrase the question: "How to measure..." and then a list of shader compilation time, modifier evaluation time, etc.

So there are a lot of different ways we divide up the operations Blender does to show us a frame (and it's always showing us a frame, whether that be in a viewport or via an explicit render.)
One way we could divide that up would be:

Blender figures out where all the vertices should be.  We could call this the "animation" part of the frame's evaluation time.

Blender figures out how to draw all the faces for us onto our screen-- what color to use for every pixel.  We could call this the "render" part of the frame.

The costs of those two things are different, and it's a useful distinction to make.  Especially in the midst of animation, we need to see our animation at a reasonable rate to judge timing, and we can do that without spending as much time rendering the frame as we would for the final render, by using faster rendering techniques like solid view (Workbench renderer.)
So with that division, yeah, we can divide models up into characteristics that animate faster and characteristics that animate slower.  But not all of those characteristics can just be added up: some of them are multiplicative costs, and some of them are permutative costs.  Basically, what that means is that they cause slowdown at different rates as complexity goes up.
1) Physics.
The way that they're typically used, the thing that is going to slow down your model more than anything else is the use of physics.  Here, the main cost is calculation of collision, and that's a permutative cost, related to the permutation of the number of colliders.  So dropping a single cubic rigid body is not slow, but at the point that we start looking at the interactions of thousands of rigid bodies, or a single "mesh" type rigid body with a vertex-dense mesh, or, say, thousands of vertices in a soft body simulation, it gets really slow.  With the way that they're typically used, any use of physics is going to be the biggest reason for animation slowness.  (We can bake the physics to eliminate that cost, but then they will no longer react to changes we make, so that's not a reasonable thing to do in circumstances where we're specifically trying to minimize animation time.)
2) Vertex count.
The next biggest thing that's going to cause animation slowdown is vertex count, but this is something where, like I mentioned before, it's not a simple additive cost.  To repurpose words used for a different field, asking whether vertex count or modifiers are more important to animation speed is like asking whether the length or the width of a rectangle contributes more to its area.  Most of the operations that will cause animation slowdown need to operate on every vertex.  So whenever we increase our vertex count, we make everything else slower.  You can get great performance from a static object with a lot of vertices; you can get great performance from a single vertex object with a lot of modifiers; but once you put a lot of modifiers on an object with a lot of vertices, you'll see significant slowdown.
3) Modifiers.
So the next things that's going to cause slowdown are modifiers.  Again, the cost of modifiers is generally proportional to the number of vertices, because most modifiers have to act on every vertex.  Every modifier is going to cause slowdown, but some of them are faster than others.  A few modifiers need to look at the relationship between two different meshes, and when large vertex counts are used, these modifiers can get very, very slow.  Good examples of this are the shrinkwrap modifier and the data transfer modifier.  Obviously, we can't go into detail on every single modifier; just recognize that the time it takes to calculate a modifier depends on the modifier in question, and there can be large differences in the time it takes to, for example, evaluate a cast as compared to a 100 iteration Laplacian smooth.
A few modifiers deserve special attention.  Subdivision surface is probably the most frequently used modifier in Blender.  In addition to requiring time to calculate, time that is proportional to the vertex count, it also creates new vertices, which increase the time it takes to calculate further modifiers.  Subdivision has special settings (render/preview iteration count, "Simplify" settings) to help manage the cost of this modifier in different contexts, but those aren't always usable.  One of the fastest things that can be done to improve subdivision speed is to simply disable "use limit surface" in its options, which increases its performance tremendously on some meshes, with very little visual difference.
An armature modifier is very important as a typical source of animation slowdown.  An armature-deformed mesh needs to perform the armature calculation for every single vertex, for every single bone to which that vertex is weighted.  So this can be slow, and the use of very diffuse weights, with lots of per-vertex vertex groups, can make it more slow (in game engines, you'll often see hard limits on the number of vertex groups per vertex.)  Compare to bone parenting, or armature constraints: we only need to do the operation once, rather than for each vertex, so those are very very fast in comparison.
Geometry nodes modifiers probably deserve special mention here.  Other modifiers can often be emulated with GN, but those modifiers can use optimizations that GN cannot.  Animating via a GN modifier is always going to be slower than using some other technique.
A special note on particles
I don't know whether particles should get their own section.  It is very easy to create a huge number of vertices using particles.  And particles can be created with their own logic, including physics logic, that isn't necessarily very fast, depending on settings.  Particles can be responsible for incredible slowdown, but they do so mostly because of the number of vertices they create.  Vertices created by particle systems are likely to cost less than other vertices, but that's not much consolation if you still need millions of them.
4) Everything else.
The other things you mention are almost negligible in their cost.  We'll go over them anyways:
Shaders do not contribute whatsoever to the animation time.  They can contribute very significantly to the render time.  Animating in a solid-view viewport eliminates their contribution to the time required to see an animation.
A "meta-rig" as it's usually considered in Blender is not evaluated except on special instructions.  It contributes exactly zero to the time it takes to run an animation.  Its complexity doesn't matter at all.
If by "bone modifiers" you're referring to f-curve modifiers, they cost almost nothing to evaluate.  Again, the reason here is due to the number of things they're affecting: when you armature deform an object, you're doing hundreds of thousands of operations (vertex count times per-vertex group membership).  You almost certainly don't have as many bones as you have vertices, by a factor of 100s or 1000s, and so evaluating this takes almost no time in real world situations.
It's the same with bone constraints, btw.  Bone constraint operations are not all that slow, but the big thing is, you're just not doing them hundreds of thousands of times a frame.  Even in a very complicated armature, you're evaluating maybe a hundred constraints a frame.  (There may be exceptions: a shrinkwrap constraint depends on another mesh, which can have a lot of vertices; a spline IK may depend on an arbitrarily complicated curve.)
Bone view contributes almost nothing as well.  The transforms of all of those bones need to be calculated anyways. so there's no marginal cost there.  The calculation of the actual view of the bone is a per-object calculation, rather than a per-vertex calculation, so again, you're just not doing the massive number of calculations you'd need to see before this was a significant part of the cost of animating a frame.
I've tried to offer reasonable advice, based on what I consider to be reasonable expectations.  For that, I imagine that an armature will have between 50 and 500 bones, that an armature-deformed mesh will have between 5000 and 150000 vertices, that a scene with a physics system will involve at least 50 different colliding entities, that a single object will average greater than 1000 vertices.  I believe those to be reasonable assumptions, but there are different ways to do things.  If at any point you have more bones than vertices, and all those bones have constraints, then yes, bone constraints would matter more than many modifiers.  But it's hard for me to imagine anybody making a file that looked like that.

great info, usefull

My understanding is that it is usually the mesh that slows things down but only if it is a very dense mesh. One way to get around that is by using two versions of the mesh, a high poly mesh and a low poly mesh, and parenting them both to the same armature. Then you hide the high poly mesh until you are ready to render the scene.
I would not think that shaders are the problem, but you can get around that using the same method, hide the high poly mesh with the complicated shaders until it is time to render the scene. Or just animate with viewport shading set to solid mode.
Animation playback performance can be helped by reducing the size of your viewport window, I usually keep my viewport reduced to a quarter screen view when watching animation playback. Having multiple viewport windows open, or very large viewport windows will slow down playback speed.

also verry handy, i could just duplicate the mesh and merge vertics in those cases,
I had never given  it a try.  but will do next time with armatures.


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How to motion track films where track points get out of screen?
Situation, a quadcopter drone video, it flies 500m away with a view corners moves  then does 360 turn and flies back. I want to camera track this, but the trackpoints get out of view after a short while. How to camera track longer video files, where trackpoints gets lost (out screen) after a while ?.
This problem was not related to the sugestion not a duplicate i found a different solution meanwhile.
I f someone removes the possible duplication mark i might be able to post the solution here.

I recommend watching the motion tracking series by CGMatter, which covers complex trackings tasks among many helpful tips: https://www.youtube.com/watch?v=WLSGG7sDEac https://www.youtube.com/watch?v=QrlxssjYeZU https://www.youtube.com/watch?v=jJ2zONKJ2Uk


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Transformation hotkeys stopped working in blender 2.82
There is something strange going on with my blend file. Although pressing S in Edit Mode to scale my meshes works just fine. In Object Mode S doesn't do anything.
This started to happen with a very large blend file and I'm not sure what option I might have accidentally triggered to cause this. I'm not allowed to scale new objects or even old ones in Object Mode. The same applies for G and R (grab and rotate). When I go to the Object Properties to edit the properties, I'm able to rotate and move the object though.
Q: Is there any way getting the hotkeys to work again?
A file with removed content and only a single cube (and maybe some shaders and textures as its still 5mb)

Are you sure that you haven't accidentally locked the location, rotation and scale (Lock icon behind the properties)?

@RobertGützkow nothing is locked in the properties pannels of a object, it also happens on new objects

Please upload a modified version of your affected project, so that it only contains a simple object like a cube but still demonstrates the issue. https://blend-exchange.giantcowfilms.com/

@RobertGützkow just uploaded it, link in question text

I'm voting to close this question as off-topic because it's about expreimental unreleased version of Blender.

Blender is in constant development many people work with development releases(even famous movies where made used non final versions) keep this question open so blender velopment can go on, as for now i want to know if it is some setting. If no one knows of a setting i post in bugtrack of blender.

@user219279, I canceled the vote because it seems the version is not relevant in this case(see the answer below), however some questions about issues in experimental versions have little value since the answers might change very quickly or become irrelevant as the daily build are... daily. I have nothing against using experimental versions, I just think that questions about them here have little value.

Well i have used Blender dev version questions they are usually for a  tillrelease period practical ater that people wound stumble on it anymore (or it be still a bug).
I think its better to ask here, you found the answer and so we didnt took time of blender developers which is OK i think.

Uncheck the Locations option in the Tool Settings bar:
or in the Tool and Workspace tab in the Properties Editor:

I must hace accidently clicked it, I wonder the purpose.
And i wonder f this behavior is a bug.
Should it be called Limit instead of options ?  (options of what??), a textual bug perhaps, maybe some room for improvement. Do you know when those option settings are handy ?

Not a bug at all. That's a very handy feature.You can move objects uniformly away or towards some center by scaling them with this options for example, or switch them places without rotating if you use rotate with this.

Bug as wrong naming for such a future i think, options is to general.

It could be called 'Tool Options' probably, but then the settings work on transform operators as well that are not 'tools' as oposed to tools in the toolbar... I think the naming is OK. You find out about it and then you know - that's all.


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Saving and loading object name location and rotation of a selection
I would like to know how I can save selected object names, location and rotation using Python in Blender 2.8 in a CSV.
And then using the same CSV apply this information to another blend file with the same objects in different locations in a new frame.
(it's not about bones it's about normal meshes).
Beeing new to Blender Python scripting, I hope for some coding hints here.
so far i got this (works in console but not in script file)
import bpy
import os
ob_active = bpy.context.selected_objects
for obj in ob_active:
    print(obj.name,obj.location,obj.rotation_euler)

That's python in blender, this is Python in Blender

well its a start (and a funny joke), the thing i have problems with is exporting and importing to a .csv

CSV is just comma separated values in a text file with .csv extension. The first Google result for "Python write to file" will help: https://www.w3schools.com/python/python_file_write.asp

yes but the way blender logs those values (as in above of my script) isnt a normal table with values logge4d as  etc

Look into string formatting in Python. You need to convert the values you are using to strings as well. You can do: some_string_var = ', '.join([str(x) for x in obj.rotation_euler]) to get the rotation values separated by commas as a string.

Surely this has been asked before?
Rather than spending any more time searching for the elusive dupe, to the export part, I'm sure it's out there
Here is an example using f-string formatting.
import bpy
context = bpy.context

def sfmt(s):
    return f"{s :10s}"

def vfmt(vec):
    return ", ".join(f"{v : 10.4f}" for v in vec)

for obj in sorted(context.selected_objects, key=lambda o: o.name):
    output = ",".join((
            sfmt(obj.name),
            vfmt(obj.location),
            vfmt(obj.rotation_euler),
            ))
    print(output)

Output of default scene, remember rotations are in radians.
Camera    ,    7.4811,    -6.5076,     5.3437,    1.1093,     0.0000,     0.8149
Cube      ,    0.0000,     0.0000,     0.0000,    0.0000,    -0.0000,     0.0000
Lamp      ,    4.0762,     1.0055,     5.9039,    0.6503,     0.0552,     1.8664

A number of other csv related questions.
How to read a csv file and use the values as x and y points in blender?
Massive import with CSV file
Moving and rotating using CSV
Generate and edit csv-file to reimport and use it with blender
How do I move an object using a csv file?
How to import a 3d object by csv file
csv file reading
Exporting coordinates of vertices to CSV
Import coordinates from CSV and create sphere at each position

thanks your vfmt   code is realy handy

Actually prob shouldn't restrict name string to 10 characters.  For any length if put last it wont naff formatting. math.degrees(v) will convert if degrees needed for csv.


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Making Flanges Around an Existing Mesh Based on a User-Defined Path
I'm using Blender to modify statues for mold making. I have this issue where I need to create and 3D print flanges based on the statue geometry. Here are two example images. In the images, I quickly took cube and modified it to match the approximate location of the flanges I want.

Now, I know how to use a boolean operator to take the difference and get the outline of the statue. But, in most of my cases, the flanges need to be curved in very specific ways. The next image shows a dramatized example path for this example. I need to create a very thin plate that matches that curve, but the curve needs to be based on the statue's mesh. Is there an easy way to do this? Let me know if I need to clarify anything! Thanks!

How do you know what "curves" are needed from that view?

I need to manually mark the "curves". They typically need to not overlap with detailed features, like ears or eyes, or text.

Can't you model the boolean object around the detailed features?

I'm not sure how to do that

Your question sounds to me you need just a thin plate to separate mold parts, right?
If so, I don't think boolean is needed here.

Add Curve object, switch to Edit mode Delete curve, take Draw tool (free-hand pen), under properties switch to Surface ... draw a shape over your model ...

Convert to Mesh ... since some points are a bit overfloating you can fix that by Shrinkwrap modifier > Apply. Select all points Extrude (E), Scale (S) ...

That is all you need I guess (if I understood your question :) ).

For a flange to be 3D printed add Solidify modifier > Apply.

Note: Similar can be achieved with Grease Pencil object. Stroke follows surface precisely, Convert to Curve, Convert to Mesh, Extrude&Scale.

Thanks! You were correct, it's just the flanges. I'm not printing the molds. I'm waiting until the bounty is almost expired before a choose an accepted answer! But this one seems to be the most straightforward.

This method should work for symmetrical models. However, if you need to work with asymmetrical models it can be adapted without too much issues I believe. Let's work with this model. First, make sure both the model and the 3D cursor is in the center of the scene. If you need to, you can snap the 3D cursor using Shift+S and clicking Cursor to World Origin.

Now, I'm going to create an 'empty' curve. Shift+A, select Curve, then Bezier. Afterwards, go to edit mode, select all verts (A) and delete them (X). This is our empty curve.
Snap your view to an axis, so you can easily draw your curve. Still in the edit mode of the curve, select Draw tool (not the very similar Annotate). On the top or in the N-panel, make sure the depth is set to Cursor. Draw the line you would like to cut.

Convert your curve to a mesh (Object mode > Object > Covert > Mesh). Back in Edit mode, select everything (A), extrude to side (E),  and scale on the axis of symmetry so all of the statue is cut.

Use Solidify modifier to achieve give the cutting object some thickness. Even really small numbers are enough, you just need a manifold object. Now, select the head in the and use Boolean modifier set to Difference, and select your cutting object as the Object. Apply the modifier.

To use this method for asymmetrical model, just create two cutting objects, one from each side, and merge these two objects in the middle.


text:
My model renders pink
When I try to render an animation, the render result of the model looks like this...

And then when I render the animation for a bit, the process makes it glitchy, looking like this:

What do I do to match the animation up with the model render??

@cegaton is't it strange that in the rendered preview the texture is shown?

can you detail a bit how you create materials for this object? can you show the nodes setup?

Blender tells it's doing sequence render on the second image which probably means there are some images/clips in the Sequence editor, could it be the reason? (and character pose there differs, like it loses rig connection) As another thing to check, do you render animation on the same computer as static image? Though for now this is in general only guesses without a file and/or more details

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


text:
How to insert the coefficients of a f-curve in Python?

I'm starting from a mesh in object mode.
I insert an animation key (I position for example).
I go to the graph editor.
I select an f-curve.
I add a generator type fmodifier.
I choose the start and end frames.

It gives me this in Python:
import bpy

bpy.ops.anim.keyframe_insert_menu (type = 'Rent')
bpy.context.area.type = 'GRAPH_EDITOR'
bpy.ops.graph.fmodifier_add (type = 'GENERATOR')
bpy.context.object.use_restricted_range = True
bpy.context.object.frame_start = 0
bpy.context.object.frame_end = 100

On the other hand, I do not know how to insert these additional lines in python which allow me to choose the degree of the polynomial as well as these coefficients.
I saw in the blender API this function corresponding to what I would like to do:
url link:
https://docs.blender.org/api/blender_python_api_current/bpy.types.FModifierGenerator.html?highlight=generator#bpy.types.FModifierGenerator
My question:
How to correctly insert in the python script of the beginning this FModifierGenerator with its degree and its coefficients? I can not do it ...
for example polynomial of degree 1:
1st coefficient = 2
2nd coefficient = 3

I fail to get your example to run, which might be in part because I don't have that Keying Set Rent available, partly because it seems as if bpy.context.object in your code refers to the object and not the FCurve, so I don't know how it should access an attribute to the FCurve like use_restricted_range
Anyway, the attributes for the FModifierGenerator are
mode which is either POLYNOMIAL or POLYNOMIAL_FACTORIZED,
poly_order and
coefficients which is a list of length poly_order+1 for a polynomial or poly_order * 2 for a factorized polynomial.
The following code adds a keyframe to the X location of the active object and adds a function modifier generator with polynomial order and coefficients set.
import bpy

obj = bpy.context.active_object
obj.keyframe_insert(data_path='location', index=0)  # X Location

fcurve = obj.animation_data.action.fcurves.find(data_path='location', index=0)
mod = fcurve.modifiers.new(type='GENERATOR')
mod.mode='POLYNOMIAL'
mod.poly_order = 1
mod.coefficients = [2, 3]
mod.use_restricted_range = True
mod.frame_start = 0
mod.frame_end = 100

If your code runs in your blender, then adding something like bpy.context.object.poly_order = 1, etc., should do the trick. Otherwise you have to find the FCurve of your keyframe channel with the correct data path according to your keying set and and modify its attributes like above.


text:
where is the error?
In this python script:
import bpy

import math

 # Place the reference of the selected 3D object in a variable

mon_objet = bpy.context.object

" We fix the object to the desired position "

mon_objet.location[0] = 2.2

mon_objet.location[1] = 0

frame_num = 0

entre_chaque_keyframe = 1

bpy.context.scene.frame_start = 0

bpy.context.scene.frame_end = 135000

for n in range(0,6300):

    x=4.4*math.cos(n)/(math.exp(50*n)+math.exp(-50*n))

    y=4.4*math.sin(n)/(math.exp(50*n)+math.exp(-50*n))

    z=2.2*(math.exp(50*n)-math.exp(-50*n))/(math.exp(50*n)+math.exp(-50*n))

    # We are on the right frame, frame_num is 0 at the beginning

    bpy.context.scene.frame_set(frame_num)

    #We create a location keyframe

    mon_objet.location=(x,y,z)

    bpy.ops.anim.keyframe_insert_menu(type='Location')

    # We increase the value of the next frame to fix

    frame_num = frame_num+entre_chaque_keyframe

my goal is to insert a position key at each new location of the object.
The successive positions of the object are in a spherical helix;
In general, this kind of script worked very well (no error) for other parametric equations but here I do not see the error.
The python console says:
"syntax error: bpy.context.scene.frame_set (frame_num)"
Why ?
Thank you for your help

You forgot the closing bracket here at the end:
z=2.2*(math.exp(50*n)-math.exp(-50*n))/(math.exp(50*n)+math.exp(-50*n)

Where to begin
As pointed out there was a syntax error with a missing brace.
Added to that
Blender uses radians as a unit of rotation. Stepping 1 radian every frame is equivalent of approx 57 degrees (math.degrees(1)) each frame, probably not what you want.
math.exp is going to grow exponentially and quite likely give math domain errors.  Try crunching math.exp(50 * 6300) into your python interpreter and see if it gives a result.  Might need numpy or use 1 for (a - b) / (a + b) when a gets large.  Or re-visit your equations for a spiral.
Break down large  formulas into smaller parts.
There is no need to either call the anim insert menu operator (IMO Never use this in a script) , consider that more of use in UI.  Use keyframe_insert(...) method of the ID object.  Can also pass the frame taking away the need to set frame each iteration too.
Below is somethat of a clean up of your script. Notice it will throw a NaN (not a number) result for z after a number of frames.
import bpy

from math import exp, sin, cos, radians
from mathutils import Vector

ob = bpy.context.object

entre_chaque_keyframe = 1

frame = 0

for n in range(3600):
    alpha = radians(n)
    m = 0.01
    a = exp(m * alpha)
    b = 1 / a
    c = 2.2 / (a + b)

    v = c * Vector((2 * cos(alpha),
                    2 * sin(alpha),
                    (a - b)))

    ob.location = v
    ob.keyframe_insert('location', frame=frame)

    frame += entre_chaque_keyframe


text:
problem: subdivision surface modifier fails on non-convex faces
Is it a known issue (in blender 3.4.1), that subdivision surface modifier fails on non-convex geometries? It results in invalid geometries.
Look at the example of a cube cut out from a cube.
It works, if I first triangulate faces. However I would like to leave the n-gons as far as possible as they are convenient in other circumstances.
Is there a possibility to only triangulate those faces that are not already convex?
regards
~eichhofener
non-convex n-gon on top:

result from subdivision-surface:

What does your geometry look like in Edit mode before adding the modifier? - If I simply use Ctrl-R to loop cut across the cube and extrude one of the cut faces it works correctly.

@John Eason:
It is really just an n-gon with 6 vertices in xy-plane extruded in z-direction.
I uploaded an example:
Your approach works, because you end up with the top and the bottom consisting of 3 faces each. Hence all the faces are convex.

Meanwhile I have read in other posts that geometry with n-gons is considered as "poor". And the algorithm was failing because of that.
So the problem is known apparently. However it is still a bug, isn't it? The algorithm should at least report about the issue in the generated mesh, imho.

This is not a bug. This is the way it works, no more... why do you want or need to keep ngons?

@eichhofener Why should the algorithm report about it? Just because it is not working well with n-gons, it does not throw an error - because it can do something with the geometry, it's just not good. And Blender does not know if you probably do not care about the result...

@lemon, @ Gordon Brinkmann: I do not want to troll around and you certainly know more about blender and the implicit contracts its algorithms come with. But before calling the modifier I have valid geometry and after calling it I have invalid geometry. Furthermore the modifier apparently is about subdivision of surfaces and it does not do so in the example but generates surfaces where there were none before. That's why I was thinking, it could be called a bug. But I got a way around it and that is all I wanted. Thank you (I learned a lot from both of your answers in my other question).

For your question if there is an option to only triangulate faces that are not already convex: it is not necessary to triangulate them, making them quads is sufficient for your case - and yes, there is an option:
In Edit Mode, go to the Mesh menu and choose Clean Up > Split Concave Faces:

Thank you! This is exactly what I was looking for. Sorry for asking too many questions. I've just started to use blender and at the beginning of the learning curve, the options are overwhelming.


text:
How to fix this error: illegal address in cuda queue copy_from_device (integrator_intersect_closest integrator_queued_paths_array)
My gpu is a gtx 2080 super and cpu is razen 3700X. I get this error illegal address in cuda queue copy_from_device (integrator_intersect_closest integrator_queued_paths_array) around 50 frames into my render. I am rendering my animation in cycles.

Try to reinstall or update your Cuda driver.

Thank you that seems to have done it got past the 50th frame

Update around over halfway through my render got the same problem

Im having the same issues for a couple of weeks and im baffled that no one is talking seriously about this issue. I get the exact same cuda error. It started by just the usual cuda illegal adress error. But no i have this long text aswell. I just installed Blender 3.0 days ago i i get this error again. So it might be Nvidia. I think il go try out a old driver and come later back here to let know if it helped.

I just ran into this same problem after upgrading to 3.5.1, and it seems related to SubSurf, somehow. I still haven't figured out the details, but an object that I have a subsurf modifier on causes crashes when I try to append it to another scene. When I open a copy of that scene with that same object in it, the subsurf has infinite geometry artifacts, and when I delete the subsurf and try to add a new subsurf to it, Blender crashes and then can't open that scene file anymore.

It might be related to the adaptive subsurf, but still not sure.

I solved this by not having both CUDA and OptiX enabled for my graphics card under Cycles Render Devices in the system preferences. Turn off CUDA if you can, as I think OptiX enables hardware raytracing.
I am guessing this was causing the render process to fight over the same resource? The documentation clearly states that you choose one or the other.

This worked. Thanks

I've recently had the same problem, getting the error messages:

illegal address in cuda queue copy_from_device
(integrator_intersect_closest integrator_queued_paths_array)

and

illegal address in cuda queue copy_from_device
(integrator_intersect_closest)

Reading through blender forums, I read that this error may happen if a ray of light does not remain within the scene but much rather travels to infinity. At some point it was suggested to add a bounding box to the scene to avoid this problem.Blender Forum
This is what made the error disappear when rendering my scene. I put the whole scene into a box (I'm sure there's better methods) to make sure the maximum path light can travel is limited. No crash so far.

Disabling overclocking on my 2060 RTX via the Dragon Center seem to have worked (at the time of writing this)

For me moving some elements around (outside of the camera frame) each time this happened, solved the issue. Its definitely a "patch up" method but helped me finish these renders, then in other project files it didn't happen anymore.

I have a GTX 1650ti Laptop GPU and a Core i7 8th Gen CPU, same thing happended to me during a 140 frame render. On the 97th frame, blender stopped rendering as I opened up a game application that requires GPU. Displaying the following message:

illegal address in cuda queue copy_from_device (integrator_intersect_closest integrator_queued_paths_array)

Sometimes if you have an outdated Nvidia driver, update it then restart blender gets rid of the problem.

Just turn off Open Shading Language in Render Settings.

Hi, thanks for the post. This site is not a regular forum, answers should be substantial, stand on their own, and thoroughly explain the solution and required steps. One liners and short tips rarely make for a good answer. If you can, [edit] your post and provide some more details about the procedure and how it works, perhaps add a few images illustrating some steps and final result. See How to write a good answer?, otherwise it may be converted to a comment.


text:
Blender 3.0 Geometry Nodes: Rotate instance to face Normals
I'm using Blender 3.0Beta, I want to align instances rotation along with the source mesh normals, I've seen people using align rotation to vector node, but it's been removed.

How do I make it so the instances(the planes) rotate along the normals?

do you mean face normals or vertex normals?

Part of this updated answer may answer this question for you

@lemon my bad, forgot to mention face normals.

@RobinBetts That also works!

you can use this node setup, here the source geometry was a torus, instance object is a plane.

here a simple cube with a plane:

Thank you! with this as a base, I found what I was looking for.

not working anymore ? (Blender 4)

@gordie: sorry, i cannot update all my answer here in BSE for all Blender versions. If you wanna know how that works for newer versions, pls aks a new question. You can open as many questions as you want. thx.

You can use the method listed above to set the instances on vertices normal, if you want to set instances on face normal use the setup below.

Things have changed as of 4.2.1 the node is now called Align Rotation to Vector


text:
Blender 2.83.5 - disable right click -> move
I just installed 2.83.5 and I am setting things up
I just cannot find where to disable 'right-click' -> moves object
I don't want objects to be move when I select them with the right button
thanks

Wait. Right click moves objects? Did you load the default settings or the right-click selection settings? Normally the right click opens a dropdown menu.

in preferences
input
untick releases confirm
but the way it feels is not like previous versions, I just hate 2.8 so far


text:
How can I make an object emit a single particle with predefined frequency
I have no actual blend file for this, as I have not managed to make it work, but in essence I would like something along the lines of a tap that drips water every 1/2 sec or so. Is this at all possible? Any tutorials I have found simply emit a no. Of particles at random with no set frequency.

If the frame rate of the output is 25, and the particle system duration is 200, we need 16 particles to have one every half second.

You can for instance use a mesh with a single vertex (if you want the drip to be at an exact position):

@Xarwolf192 The answer from lemon is exactly how I do it. But even a dripping tap does not necessarily have a perfect frequency, the main thing you need to make sure is that you set the number of particles low enough for the span of the animation so that there is no chance to get more than a single particle at once. Only thing I would change is setting the normal velocity to 0 m/s so the drops won't jump up at first. But that's just nit-picking from me  ;-)

@GordonBrinkmann, if from vertices the particle won't jump as no normal (i made the gif before changing the setting above). And you're right water drip is pseudo random.

Oh of course, you're right... no normal direction to follow ;) My bad..

@GordonBrinkmann, interesting about that https://www.youtube.com/watch?v=ovJcsL7vyrk

Yes, very interesting video. I've been reading a lot about chaos theory etc. in the past. But actually the particles for this water dripping won't have to be erratic since the water flow shouldn't change much ;)


text:
Rounding and alinging surfaces
i modeled a bigger ship and the hull part is too edgy. So i want to align this part and make the shape more rounded like 1 fluid line. Are there tools to do this or maybe a workflow.

The first is my reference. And like you can see in the render the hull is very edgy maybe i have to solve this whith a texture and the shader nodes?

Hello, a few screenshots might help us help you

i added them on top


text:
How to make a 360 degrees render showing the wireframe
Hello I want to make a render of an object that rotates in 360º but I want to show the wireframe of it, anyone can help me?

A very basic setting can be:

Turning 360° is done with geometry nodes. Simply rotate around Z along time:

A modifier stack with a fireframe modifier and "replace original" unchecked and a material offset of 1:

A shader that let appear the wireframe with time:

 (Blender 4.0)

i love your solutions...but....this time, i personally would prefer to have it all in GN....wireframe is very easy to make with mesh to curve and curve to mesh, and i know that you know that. so why did you create a 2nd modifier here? ;) +1 anyway

@Chris ... Friday evening lazzyness, maybe :)

Instead of Render > Render Animation, make sure that you are in camera view and go into View > Viewport Render Animation, it will render what you currently see, whatever is your display mode. Afterwards in the Video Sequencer you can fade in this sequence with a real render:


text:
how do I show the box with all modifiers (Blender 4.0)?
How do I show the box with all modifiers? This is what appears now

They changed this in 4.0, you now have them grouped in categories. Like the ones that before were above the columns as a title.

Either start typing the name of the modifier you want or click on one of the entries to show the whole list for that category.


text:
Missing tools from my property panel
I am following a tutorial for rendering with Blender, and some of the tools that he is using in the video don't appear for me. I have the navigation menu up fine, and most of the tools are there, but for example the lightbulb is missing and I don't know how to add it on.
Attached is the photo of his navigation bar compared to mine. Any advice?

It seems a light object is selected in the video. This property panel is contextual (the content will depend on the selected object)

Those are not "tools" they are properties tabs, and they depend on the currently active object. If you don't see what you expect it is because you have the wrong object type selected.

The only thing that's a bit strange is that in your screenshot where you obviously have a mesh object selected, the Collection tab is missing. Could it be that you are using a much older version than used in the tutorial? At least I don't know a setting where you can disable the collections...


text:
How do I call a function from within an external class?
I wrote a code that works fine when I copy and paste it into the scripting area of Blender. Now that I've made an addon out of the same code though, I'm getting errors. I believe one of the errors is due to the way I'm calling the function in an external class. Is there a different way of calling it while avoiding the error?
The error looks something like this (I've modified it to correspond with the code snippet below):
Python: Traceback (most recent call last):
  File ".../Blender/3.5/scripts/addons/test.py", line 119, in execute
    bpy.ops.object.my_external_class('INVOKE_DEFAULT')
  File "/Applications/Blender.app/Contents/Resources/3.5/scripts/modules/bpy/ops.py", line 111, in __call__
    ret = _op_call(self.idname_py(), C_dict, kw, C_exec, C_undo)

I also tried using EXEC_DEFAULT but it provided a similar error message.
Here's the simplified code:
class myCallingClass(bpy.types.Operator):
    """My calling class"""
    bl_idname = "object.my_calling_class"
    bl_label = "Calling test"

    def execute(self, context):
        bpy.ops.object.my_external_class('INVOKE_DEFAULT')
        return {'FINISHED'}

class myExternalClass(bpy.types.Operator):
    """My external class"""
    bl_idname = "object.my_external_class"
    bl_label = "External test"

    def execute(self, context):
        print("ok")
        return {'FINISHED'}
```

Most likely you've not registered myExternalClass.

No it's definitely registered properly but thanks.

I can not reproduce your issue, so maybe something that is not shown in your question is the cause of this error.


text:
How do you make bangs with hair dynamics?
I gave up on just trying to add hair physics to an already made hair mesh, so I decided to finally look at the hair dynamics that's been haunting me the past few months.
I was really impressed when I saw a tutorial on it, and now I want to try, but I only have 2 quick questions.

How do you make bangs with hair dynamics? I saw someone do it with bangs but you have to pay for a tutorial... it's probably just like fixing the hair strands a little bit but if there's an easier way can anyone let me know? And ...

Is it possible to have multiple hair dynamics on one mesh? These questions are kind of dumb, considering they probably have easy answers, but I guess I'm just looking for a confirmation. I think you'd have to just apply more strands on the mesh, correct?  And if it is, is there a way to get it to move separately from a different one?For example, say you wanna have long hair at the back and then two side braided ponytails. You'd do the back first and then create more strands to make the ponytails, right? But what if you accidentally move the back hair?

So there's that, I'm sorry these are so simple but this is my first time ever looking into hair dynamics. ✨

About 1.) can you give an example of what you're looking for? Bangs at the forehead or at the sides? What's the problem related to Hair Dynamics? About 2.) Yes, you can have more than one Hair Particle System and each particle system has its own settings. With the help of the Density group, you can specify where the hair should be.

@Blunder Forehead bangs.

What's the problem related to Hair Dynamics?


text:
Beginner Animator: Unable to unify FK & IK in animation (footage of issue linked)
I had initially thought that rigifying the metarig to the body would unite the body with the rig, but I am missing some fundamentals here I assume.
Moving my IK is independent to the FK, as shown here: https://clips.twitch.tv/CreativeSpineySrirachaPoooound-utS8Ml-oge6JPvMF

What am I misunderstanding? Why can't the arm just pose with the rig? I also thought the dotted line meant a parent-child relationship... Not sure anymore...

It appears you have the two rigs separated on two different layers? If that's the case, then I believe the only way to make the fk snap with ik is by scripting it (this is what I've read from other forums; I haven't actually tried it myself)
edit: also note, you'll need to create switch between fk and ik using drivers first (if you haven't done so already)

Rigify's generated rig comes with FK and IK control bones. The meta rig is just used to align everything in its place. The FK (green) and IK controls (red) work independently from each other. Default is IK.
In the N-panel there are buttons in the Rig Main Properties section. There, you can switch between IK and FK with the IK-FK ("bone name") slider (0=IK, 1=FK). Or use the snap buttons IK->FK ("bone name") and FK->IK ("bone name") to copy the pose and sync them.

(hand.L is the bone name of the left hand in this example)
Tutorial video: [Blender 2.8/2.9] Rigify Tutorial #08 - Posing the Rigify rig


text:
Is my alpha messed up?
I used some of the shaders from the tutorial "How to make the Iron Man Nanotech effect in Blender". The shader is controlled by an Empty object and should make the model fully transparent when the Empty is far away. The closer the Empty has moved the more of the model is revealed by the "materialize" effect.
So the hands, legs, and eyes have their own material with the effect shader (a node group) and are supposed to be fully transparent when the Empty is not near. But they are always visible no matter where the Empty moves. It looks like this:

It's not really identical. How do I fix this?
Here's the link to the file: Blend file (google drive)

It might help if you could provide your .blend file for us to take a look at - https://pasteall.org/blend/

The tutorial is about making a transition of the material disappearing/appearing, and your material looks like in middle of that transition... So it looks like it works...

https://drive.google.com/file/d/1ZzO4p00PdjQAyNRivtIUgJns4K6j3LnD/view?usp=sharing
heres a google drive link

What is the actual problem? The eyes are not transparent? A brief description of what you expect is helpful to answer your question. And you can add a link directly to your question. So it's immediately visible. If there are many comments only the first few and the up-voted comments are shown and your link can get hidden.

I highly recommend giving the materials proper names! This saves you a lot of confusion. The body material uses the output of the shader group for the Alpha of the Principled BSDF directly and it works as expected. The eye mask does not use the shader group at all. The Alpha value is here always 1. And in the materials of the hands and feet, you mix the output of the shader group with the Alpha of the image texture which is probably 1=no transparency (textures are not included). The result is a 0.5 to 1 = always semi-transparent to fully visible. Fix: remove the Mix RGB nodes.


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How to keep all the islands facing the right direction (UV)?
I am looking to make all the island facing the correct way. I can use a texture with arrows to help me, but it will be difficult to notice the small mistakes. How can I have the islands all facing the correct direction?

I don't really understand what you mean. What are your islands? How do you want to position them? By facing do you mean "all upwards" or rather "same rotation around Z axis"? Maybe add a screenshot?

Not in UV unwrapping's nature to maintain "direction" of your 3d view as much as filling up the 2d space while minimising stretch. I'd suggest unwrapping each island with Project from view, always with the right side "up". Cube projection or Follow active quads can also sometimes happen to project everything right-side up, depending on your mesh. Does the UV map need to be that exact that rotation by-eye (zoomed in) won't suffice?

In 3D-View-Window press N for opening Properties.
Under "Mesh Display" you find "NORMALS:" press the "Face" Symbol. If you now go with your mesh to the Edit-Mode you see little lines coming out of the center of each face (These lines show the Normal direction). With "Size" in Properties-Panel you can change the Length of the these lines.
Now choose all your faces and open Tool-Shelf by pressing "T". Under "Shading" you find "Recalculate". All Faces should now look in the same Direction. If any of your faces should not, select these faces manually and press "Flip Direction".
"Recalculate" could not work perfectly when your faces are not connected (Island-faces?????)


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Get properties from different scripts in game engine?
The question explains itself. I have a property in one script and another property in another script. I am not sure how to define the python scripts in the blender game engine. How can I get a property from a different script in the game engine?

Properties belong to game objects rather than Python code.
You write a property with myGameObject[propertyName] = value
example:
hitObject = sensor.hitObject
hitObject["detected"] = True

You read a property with value = myGameObject[propertyName].
example:
hitObject = sensor.hitObject
wasAlreadyDetected = hitObject["detected"]

I hope it helps

So, if properties belong to game objects, when would I use properties in python code? Also, thanks for the answer! ;)

I may misunderstand you, but you use properties when you want to store data at a specific object. Your python code lives as long as the code gets executed. That means all variables will die after exiting the python controllers execution. When you store values in a property you can access it from a different Python controller execution either from same or from other object.


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Have a ray create a force?
Scene:
I have a simple weapon system: weapon which has a ray that collides with game-related objects (i.e. objects that can collide with player); an empty that is always at the end of the ray; and, on a trigger (left click), an object (damage object) is added to the end of the empty, the object changes the health value of an opponent when collision occurs. There is also an opponent, for the simplicity of this question, a cube set to dynamic for physics.
Problem:
I am trying to get the ray to exert a force the way it is facing/going. I'm not quite sure how to create such an idea in the game-engine. How can I have a ray create a force facing the same way the ray is facing/going?
Include/Note

Force only affects certain object(s). This/these object(s) are whatever the damage object collides with. In other words, the force will affect no object but those that the damage object collides with. (You can have it collide with the object(s) the ray collides with if you can't do this)
Force does not decrease/increase strength over time; force is constant.
A property that defines how much force to use.
A property that defines how long the force will last.
Please try to answer in python.

Any help is appreciated. Thanks!

Due to the dynamic nature of that operation you need a Python controller to apply that impulse/force.
I suggest to use a ray sensor. It provides the object hit, the position where it was hit and the direction you measured.
Usage
Place this snippet in a python file force.py
import bge
import mathutils

PROPERTY_STRENGTH = "strength"
DEFAULT_STRENGTH = 1.0

def applyAtHit():
    if not allSensorsPositive():
        return
    sensor = getDetectionSensor()
    affectedObject = sensor.hitObject
    hitPosition = sensor.hitPosition

    strength = getOwner().get(PROPERTY_STRENGTH, DEFAULT_STRENGTH)

    direction = mathutils.Vector(sensor.rayDirection).normalized()
    force = direction * strength

    affectedObject.applyImpulse(hitPosition, force)

def getDetectionSensor():
    return bge.logic.getCurrentController().sensors[0]

def getOwner():
    return bge.logic.getCurrentController().owner

def allSensorsPositive():
    for sensor in bge.logic.getCurrentController().sensors:
        if not sensor.positive:
            return False
    return True

Apply following logic to the measuring object:

Setup a ray sensor (must be the first one) with a distance that covers the range you want to have, [True Level Triggering] is not needed as you want a single impulse
Setup a Python controller in module mode with Module: force.applyAtHit
Ensure detected objects are physics objects (dynamic, rigid body, softbody)

How does it work?
When all sensors are positive and any of the sensors triggers the controller the function applyFromHere() will be executed. Each run will apply exactly one force or no force at all.
That is the reason for [True Level Triggering] disabled. This prevents subsequent execution unless you "activate" again. Means you need all sensors positive and at least one to trigger.
The ray sensor checks for an hit. The Python controller calculates the

the affected object
the direction towards the affected object
the strength of the force

With that the Python controller applies the individual force to the affected object. Here we use applyImpulse(). This does not just affects the linear motion, it results in change of the torque too.
I hope it helps


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How to define a mesh?
For defining objects, the usual scene.objects["obj"] works. I am trying to do the same concept but with a mesh. How can this be done?

Following my previous answer here, you want to get the mesh (one of them), not define it. To do that you should use obj.meshes[0] (since usually there is only one mesh).
You can find the BGE API here. Of particular interest is the KX_GameObject class, where most of BGE coding is actually done.

Thanks for the answer. Also, will it work if I define this: obj.meshes[0]? You stated to call it, not define it. If I will use it a whole lot, will it be fine if I define it or will it just not work? And how can an object have 2 meshes? If I change the mesh of an object, does that mean there is a new mesh?

An object can have a display mesh and a physics mesh. But this is not what it provides. KX_GameObject.meshes provides display meshes only. I never saw an object with more than one mesh.

You can store the mesh in a variable for local use (mesh = object.meshes[0]). But I strongly advice to avoid to store context data (such as current scene, current controller, current object and current objects mesh) outside the context (e.g. at module level or a property of another object). This will result in hard to investigate side-effects.


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How to make a point out of 2 intersecting lines?
I have 2 lines, and I want to get the point where they intersect. I am looking to have a point created on the point of intersection. How can this be done?

Oh. It is a dupe. My bad. Do I delete?

Two line maybe not even intersect, not even in 2d if they are parallel, well there is cheat for it:
https://en.wikipedia.org/wiki/Line_at_infinity
In blender we work with vectors in a 3d place and not with real numbers but with floats. So a pure mathematical solution is maybe unusable, I wrote this because the question is pure mathematical. If we rephrase it for 3d modeling:
Can I make a vertex at the intersection or mutually closest point of two edges. We will get a duplicated question:
How can I add vertices to intersection of two edges?


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Variable representing object's rotation minus another object's rotation not working?
Here's my code:
import bge
from bge import logic
from math import degrees

def mimic_process():

    cont = logic.getCurrentController()
    own = cont.owner
    own_rotation = own.worldOrientation.to_euler()
    mimic = own.parent
    mimic_rotation = mimic.worldOrientation.to_euler()

    own_rotation_x = "%.0f" % degrees(own_rotation.x)
    own_rotation_y = "%.0f" % degrees(own_rotation.y)
    own_rotation_z = "%.0f" % degrees(own_rotation.z)

    mimic_rotation_x = "%.0f" % degrees(mimic_rotation.x)
    mimic_rotation_y = "%.0f" % degrees(mimic_rotation.y)
    mimic_rotation_z = "%.0f" % degrees(mimic_rotation.z)

    rotation_fix_x = own_rotation_x - own_rotation_y

    if (own_rotation_x > mimic_rotation_x):
        own.applyRotation((rotation_fix_x, 0, 0), True)
        print('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA')

    keyboard = bge.logic.keyboard

    if bge.logic.KX_INPUT_ACTIVE == keyboard.events[bge.events.OKEY]:
        own.applyRotation((0.01, 0, 0), True)

mimic_process()

The line rotation_fix_x = own_rotation_x - own_rotation_y is the cause of the problem. I got my object's rotation, put it in a variable, did the same with another object [the mimic object], and attempted to subtract them out. I don't know why it wont subtract them. How can I fix this? Thanks.

Only use the formatting strings "%.0f" % degrees(mimic_rotation.x)to format output to print statements, file etc, not to set values.  The formatting converts the value to a string.  Feel somewhat responsible as this was taken from my answer to your question  https://blender.stackexchange.com/a/41328/15543.
Use round or floor if you want just the integer part here, although I'm not really sure what you are trying to achieve.  Are you trying to restrict values to whole degree amounts?  As pointed out previously blender uses radians as its default unit.  http://bgepython.tutorialsforblender3d.com/GameObject/applyRotation
rotation_fix_x = own.rotation.x - mimic.rotation.x
if own.rotation.x > own.rotation.y:
   own.applyRotation((rotation_fix_x, 0, 0), True)

The above would work ok because it is dealing in float types, but wouldn't set to a whole degree amount.
Here is some console code from bpy looking at the rotation_euler.x of an object
# rotation.x in radians
>> C.object.rotation_euler.x
1.1093189716339111
# rotation as degrees.
>>> x = degrees(C.object.rotation_euler.x)
>>> x
63.5592952084158
# rounded to a whole number
>>> y = round(x,0)
>>> y
64.0
# how much to add to C.rotation_euler.x to make it whole number in degs.
>>> fix = radians(x - y)
>>> fix
-0.007691749642459737

To step in degrees use radians(1) when applying your rotation from the kb.


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ball duplicated by symmetrical mirrors
My goal is to symmetrically place mirror modifiers on a sphere where each mirror object of the modify is an empty one in order to duplicate this animated sphere
no initial sphere duplication
1st duplication 2 spheres
2nd duplication 4 spheres
3rd duplication 8 spheres
etc ....
I am looking for tutorial or blend file realizing this perfectly
I did it with mirror edit but I can not do it properly
see link file blend not correct: https://drive.google.com/file/d/1vU5ZEYNjSGCeqgB5dQDbDoZjenU3LDHH/view?usp=sharing
I would like the trajectory of the sphere to be like that in this image
see link file:
https://drive.google.com/file/d/1LiFCCM9qbVKixzwTjazSkdRRUlSvtU41/view?usp=sharing
Can you help me?
Thanks

Better use an Array Modifier?

I downloaded your .blend file but I am unsure what it is you are trying to achieve. Can you add images to your question explaining what you need and how it should work. Try an show the simplest example.

I would create the pattern in a Curve and then use Duplivert to place a Sphere at each vertex. You can import the Curve as an SVG if it is easier to create in another program. Each vertex location can be edited in the Propertied panel if you have the math. Or you could look at Python and script the creation of the mathematically correct curve.


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create surface math with geometry nodes
I want to create a basic surface z=square_root(x^2+2*y^2) using only geometry nodes like this:
https://i.sstatic.net/TeKkf.jpg
I don't know to which type of mesh I should apply this geometry nodes.
In my opinion, I have to add a vector as input in the geometry nodes but nothing is drawn for me
Can someone help me?
thanks
I don't understand why this nodes configuration doesn't give me another desired function z=square_root(4-x^2-y^2)

You could just generate a Mesh Primitive > Grid, and set its point-positions to (x,y,f(x,y)):


text:
How do I get a transparent background with multiple render layers
I am trying to get an animation that has 3 render layers to have a transparent background.
How would I do this?
Simply checking the transparent box under film does not work with multiple layers
Thanks for any help.
(Cycles)

Yes I am. I will add a picture to show you the nodes.


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Cloth Simulation Rips my mesh
When I use the cloth simulation and try to make an animation with it, the mesh is ripped into many layers and pieces for some reason...
Any idea why this is happening?
Thanks
Blend File:

Impossible to say for sure based on just this. Generally share your blendfile, or share thorough information about your settings and parameters.
Generally scale can cause lots of issues so that would be my first thought.

how do i upload my blend file?

I added the blend file

the cloth mesh is too messy. it has double vertices, extra faces, etc. Try to use the planes without thickness for the cloth. You can solidify it later, after the cloth modifier. Also the pinning group is strange. Try to play with simple square sheet with pinned corners to get familiar with cloth, then gradually increase complexity.

Ok thanks. This cape model I actually didn’t model myself it’s downloaded so I’m not familiar with it. How would I go about cleaning it up for use with the cloth modifier?


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Volumetrics render different in viewport vs final render
When using volume scatter on a massive cube, with an hdr image for lighting, I’m getting wildly different renders between what I see in my viewport vs what I get in my final render.

I thought at first I had something turned off in the viewport that was visible in the render but that’s not the case. I almost think it’s something to do with the hdr image and how the volume scatter renders in front of it? I can even turn up the density of the volume scatter until the viewport is nearly black, and the render will be just a slight bit darker.
I much prefer the viewport results and I can’t figure this out.
Thanks!

Hello could you please keep only several objects of your scene (enough to see the problem) and share the file?

I have added the blend file, hopefully this can help determine the issue

In the file you share the volumetric cube is disabled for render, if I enable it I can't see any difference between preview and render, Also I can't see any image texture in your materials, I'm not sure it would make a difference, but I don't see the same thing as what you show

Changing the Camera Clip Start & End values to match my viewport's fixed it for me.
Viewport:

Camera (Render):

It might have something to do with your render settings varying from your viewport settings. Could also be the number of light paths you have set for volumetric. I believe there is a weird bug with the volume being plugged into the world shader when using an hdri but if you are just using a cube then it should be fine.

To add to that answer from Isaac , there's a forthcoming fix mentioned in today's Blender Today Live video at this timestamp which might be relevant here.


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Particles rendered with hair system do not show in final render
I'm making a cactus using spines rendered using a particle system. When clicking F12 to render they do not show up at all. What did I do?

Because thanks to Displacement the Hairs left inside ... if you disable Displacement they are rendered ... just for some reason your file crash any time I opened it. I had to append all objects into a new file and disable cactus material to stop crashing.

I recommend geonodes for all of this, now, because particle systems do not respect mesh displacement from the shader tree.


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Arch linux hip error
I have installed rocm-hip-runtime from the AUR to implement HIP support for my AMD GPU and my GPU shows up in blender's hip settings, but I get this error when I try rendering:
HIP hipcc compiler not found. Install hip toolkit in default location

This is an issue with rendering with HIP in blender

The Arch wiki suggests adding "/opt/rocm/bin/" to your PATH.
You could test by running env PATH="${PATH}:/opt/rocm/bin/" blender from the terminal.
This should allow your machine to compile the "HIP kernel" that Blender uses. To add the environment variable permanently see the arch wiki. If this does not work you may need more of the ROCM / HIP installed.
Please save you work before testing Blender as it will probably lockup your system


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For Armature linking, is there a maximum number of faces allowed?
I've created an armature for a character, but when I run CTRL-P-I to set the parent with automatic weights, my computer chugs for a bit but when it's done and I use pose-mode, the armature doesn't affect the mesh. And if I look at the weights, they're all the darkest blue.
If I decimate the mesh before parenting the armature, it worked. Is there a max-mesh complexity for which this will work? If so, is it a fixed number or computer-dependent?
EDIT: Ok. I lied, I do get an error, but not in the console, but where I said there wasn't one, the notification area at the top:
Bone Heat Weighting: Failed to find a solution for one or more bones.

EDIT: FYI, the mesh starts with about 1/2 Million Faces, and it successfully rigs when I get to about 60,000.

This sounds weird. Are there any error message in the console? Can you upload your blend file?

There are no error messages. I will look into how to upload here, I've never done that before. (I could link to a cloud drive right away, but I'm unsure of the etiquette on that.)

I should add that I've tried all the tips I've found, which involve removing doubles, making normals consistent, and other cleanup mesh operations.

I should say there were no errors that showed in the notification area at the top, but I didn't check the console. I will do so.


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Projection mapping terrain from elevation angle photo
I am trying to recreate a riverbank [Note: not the fort/buildings]from an historic photograph:

I'm having trouble finding a tutorial as the terms I'm using in my searches predominately bring up other kinds of projection mapping of terrain; it's all aerial views and DEM models from cloud GIS services. Here, I know I will need to create the geometry myself, but my efforts have not gone well:

Can anyone offer any advice on a workflow that might yield better results?

Probably you will find this projection useful https://blender.stackexchange.com/a/226920/2214 ... There is nothing to say about modeling ... manual work - sculpt terrain, add mesh primitives as buildings ...

@vklidu I probably shouldn't have cut out the buildings because that probably makes it seem like I wanted to model them, too (I do! And have, already from diagrams). However, as this was a fur-trading fort in Canada, its relation to the river in the foreground is really important. It's the character of the riverbank I am trying to reproduce. I will try sculpting as that will probably produce better, organic-looking, results. Thanks.


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How to make realistic pockets of sand?
I want to add sand around the small rocks in this scene but I'm not sure the best way to go about it.

Ideally, I'd love to increase the rocks by millions, but obviously that would increase the poly count like crazy.  Is there a way to add sand/gravel without looking like blobs with noise texture?
Here's a reference I am using:

Could you post some reference images?

Good idea.  OK I have posted the reference photo.

I think you would find blenderguru's Make Mars tutorial interesting.

That's actually what I was following but I had to modify it to have more rocks and be in a valley...and also to use my own rocks instead of the "rock essentials" which he tries to make you buy :) But it's a good tutorial though.

You can perform this in several ways: you can create a particle system, you can UV paint where you want the sand (with a sand texture image), you can paint influence areas to switch from selected textures or you can make Blender automatically blend two (or more) textures based on your model geometry (height, normals, etc). The following node setup shows an easy way where i use model's height to blend a gravel image with a grass image (higher levels of topography have grass, lower levels have gravel). You can control the blend position by controling the color ramp, and you can control the image scale on the Mapping Node's point scale. I've remembered this solution because in your reference image, the sand is always at lowest height levels. You can switch raster textures with procedural textures.

This is an interesting and good method, but how would I be able to make convincing textures up close like the reference photo I posted?  Is there a way to make it less poly when the camera is far and higher poly when it's close?

if I understood correctly, you just need to play with the scale of the textures. You can fake 3D small details, ripples or dunes with a to scale bumpmap or normal map. You can attach a bump texture to a bump node, then connect it to the diffuse nodes (example a single diffuse node will have a color texture, like RGB or procedural, and a bump map with faked 3D detail).

as about increasing resolution based on distance (also known as level of detail), you can search tutorials on microdisplacements - like this one: https://www.youtube.com/watch?v=dRzzaRvVDng)

about what i said earlier, dont forget to connect the mapping node to the bump texture you use, so it keeps scale no matter the distance

Sorry for the super late reply...took me a long time to get it just right.  Totally worked though thanks!

that's great :)


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Is there a way to make custom coffee foam?
I want to make a cup of coffee with the nice swirl of white and brown foam, but I want to be able to influence it using an object (similar to how they make hearts in cappuccino).  In this case it's an .svg logo I would import.  I've seen lots of examples where image textures were used for foam, but I'm wondering if there's a way to actually influence the foam in Blender itself.  Is this possible?
Here's an example of the type of foam I am going for:

And here is an example of a logo I would want to use as the design in the foam:

EDIT:
Here are the changes I made based on responses provided.  I modified the node setup slightly in that I did not use the coffee nodes as I decided to just use an image texture for that.  Unfortunately, it made the logo part heavily distorted and I'm not sure why.
Here's the node setup:

Here's the result:

I've attached the .blend:
NEW EDIT:
Based on the follow up answers provided, here is the finished render (including blur techniques used in GIMP):

Use the image as a mask to separate two shaders and as a bump map.

This may be of some help https://www.youtube.com/watch?v=4rNrL7a12xg&t=2694s

@Timaroberts do you mean using a mix shader with both images?

@cegaton same question I asked Tim

@icYou520 thanks!  I checked it out before asking this question, but it didn't have the effect I was looking for.

@cegaton I've posted my images and .blend

It's not extremely good, but this should give you a good place to start:

The image you want to appear on the foam is very detailed and hard to reproduce on real coffee. This is why I thought it should be pre-processed in some image editing software to make it more realistic and doable. I used Photoshop to smudge out the image a bit, and I got this:

The coffee itself that I made in Blender was a simple squeezed sphere. I then used the image above as a texture to determine the color of the foam. Here is my node setup for the foam:

I'll go into the details now.
Distorting the image
I used a Wave texture to distort the image in rings. You can adjust the frequency and amplitude of the distortions.

Some noise texture on top of that
I added some noise to the image, because nocoffee is perfect.

Bump map
I didn't have any actual coffee to look at, but I'm assuming that the image should have some effect on the bumps in the foam, due to stirring. So I created some "ripple" bumps around the borders of the texture (kinda):

The coffee shader
Now, we have calculated both the texture we want on the coffee and the bump map. I used a gradient to get the right coffee colors. The actual shader was a simple mix of a diffuse shader and a glossy shader:

Here is my resulting .blend file you can play with:

Here are some possible improvements you could consider:
- It is very easy to adjust how much you want the image to be distorted in rings. In the "Distort Image" frame, just change the second value of the Divide math node.
- Consider introducing a subsurface scattering component, because coffee is transparent. Or, even better, use a volume shader. Coffee is a little bit transparent.
- You could change the colors to make them a little warmer, because my coffee looks like mud. Yuck. :)
- You could further tweak the original image: smudge it, adjust contrast, add noise, etc.

thanks for this incredibly detailed answer and effort!  Unfortunately I was not able to reproduce the result (I tried to create the nodes from scratch so I could better understand).  I've posted the .blend and my setup in my revised question.  Let me know what you think...

@lakerice I think you're on the right track! I looked at your node setup, and noticed two mistakes: you used a color mix node instead of the mix shader, and the math node where you need a vector math node. Here is a .blend file where I fixed these mistakes, so the texture works now. But you still need to work with the colors. Good luck! :)

Oh that makes sense!  It's easy to mix up (no pun intended) those nodes.  One more question: is it possible to make the logo bubbly like the coffee texture?  Or make it take on the bump of the coffee texture?

@lakerice, I'm not sure what you mean by a "bubbly" logo, but you can definitely add a bump map with bubbles. I would try to use the Voronoi texture with a scale of ~150, and plug that into the Bump node (you can input a normal in the bump node to combine two bump textures). Then send the output to the material's normal. (You could also mask it so that it only affects the logo, but that's too long to explain in a comment.)

sorry for the late response.  I tried using the voronoi but I wasn't able to achieve a realistic result (at least the way I tried) but I ended up using the bump for the coffee image for the logo as well so they basically followed the same texture.  Also, I used blur techniques in GIMP to get a more blended result (I'm sure there's a way in Blender but for convenience sake I just manipulated the logo .png itself).  You can see my finished result in my question if you like :)  Thanks again for your help!


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How to make a wiggly animated curve?
I'm trying to make a curve move in sort of a worm-like fashion, and I'm not able to get it to move properly with F Curve modifiers.  Basically, I want it to move in a looped "s" shape pattern.  How can I achieve this?
This is the pic; the curves are the yellow beam and the electric forcefield wrapping around it.  I used displacement modifiers for the ripple effect.

Basically, I want to animate the curves in an s-shaped pattern like in Ghostbusters:

Have you tried giving the curve a Wave Modifier?

Yes but it seems to only ripple the curve in a completely stationary manner...kind of like it was made out of cloth and wind is blowing on it but it just ripples. It doesn't have that dramatic worm wiggle effect.

Do you have a visual reference for the kind of movement you want? If I'm imagining correctly, a worm mesh using a Curve Modifier might be your best bet.

Just added some reference photos...the first is my render and the second is the effect I'm going for.  Let me know if you need more info.

Good ol' fashion hook modifier.
One way to set up a hook.
Snap 3d cursor to control point of curve in edit mode, then in object mode add an empty.  With the empty selected, shift select the curve return to edit mode,  and "Hook to selected Object" (from space search).

Now you can animate the position of the hook to manipulate your curve.  Adding more hooks will give you more control.

Pretty crappy gif, but you get the idea.  The empty is hooked to the right control point of the default bezier curve. The empty is animated to rotate and follow a circular path.

Hook to new object will create the empties for you.

@sambler thanks, an easier way to add hook..  I don't use the UI enough and prefer to do things via script.  The noise will indeed give it a buzz. Will get back and edit ... or feel free to edit in... who you gonna call? 8^)

@cegaton probably duplicate of?

This was exactly what I was looking for!  Don't know how I forgot about the hook modifier.  For some reason it only worked for me when I selected the specific vertex in edit mode and pressed ctrl + h.  Anyway, same thing.  Also, instead of keyframing and shapekeys (thanks @cegaton), I found a much easier way to get the effect I wanted was the noise modifier on the empty...pure repetitive wiggleness :)

As per @cegaton's request, I'll show officially how I fixed this.
STEP 1: Select a vertex of your curve that you wish to be able to animate in edit mode (it has been beveled to give it a 3D look) .  Press Ctrl + H and a simple empty should appear.

STEP 2: Go out of edit mode and select the empty.  The hook modifier will be automatically placed on your curve with the empty you just created as the object of reference.

STEP 3: Select your empty and keyframe your it wherever you want to start the animation (simply press "i" and select location in your timeline for the keyframe).  At this point you could place your empty wherever you want and keyframe it manually in different places.  But for creating a dynamic and somewhat random squiggly effect, it's best to add a noise modifier in the F-Curves panel in the graph editor.  So go to the graph editor view and select location.  You will see the X, Y and Z axes of your empty. You can then copy or make new noise modifiers for all axes.  You will have to play around a bit with the settings though to get your animation the way you want it.

STEP 4: Press play and watch your proton pack's laser come to life...just don't cross the streams ;)


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Blender - show edges angles “direction”
I'm working on a papercraft project on Pepakura.
Valley folds show in light blue and Montain Folds in dark blue in this software.

I was wondering if there is a way to show the angle of the folding edges directly on Blender ?
Thanks :)

Please edit "I'm working on a papercraft project...in dark blue" into two sentences. I had to re-read that nearly 10 times before I concluded that light folds are called "Pepakura and Valley" and dark folds are called "Montain"

Closest thing I know in Blender is using Mesh Analysis from the Properties Side Bar.
Enter Edit Mode on a mesh object, turn on Mesh Analysis, set it to Sharp and adjust the angles as desired.

Have in mind that it can't highlight single edges as illustrated, only face angles. Not sure if it can both show concave and convex edges at the same time.

In edit mode hit "N" and look for the Mesh Display tab.


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Eevee - problem with lighting, mesh is darker in some places
I'm trying to set up a studio lighting scene for my objects renders but something weird is happening and I can't figure out why.
I'm working with Eevee and looks like to top part of my mesh is lit from the back instead of the front.

From the back, you can see the right lighting.

I looked up if it wasn't due to the faces orientation/normals but everything seems fine.

Any ideas ?
EDIT : Here's my scene

Could be flipped normals. Go into edit mode and press SHIFT+N.

Already tried fixing the normals, everything is facing the right way :/

Unchecking the toggle Context (tab) > Normals > Auto Smooth worked for me.


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Blender Eevee Vector Motion Blur?
So I am trying to use Eevee to render this animation, and I want to add motion blur. I like using the vector blurs in cycles but is there a way to use the nodes in Eevee?
I don't see a way to add a vector pass for eevee like in cycles

Vector motion blur is a Cycles feature, that requires raytracing as far as I know, I'm not sure if it is possible for OpenGL based renders

Thanks. I guess I'll hafta add in motion blur in my video editor.

You can use a mix of both renderers to get a mask. The Cycles scene would be super extra low fi to give you a fast render, and then you grab the Vector and the Depth from it and use it on the Composite screen to mix with your new Eevee render.
Here is one example of how to do it:
http://blenderboydiaries.blogspot.com/2019/01/how-to-get-motion-vector-blur-in_17.html

Blender 2.90 now supports Eevee motion blur, but is known to be unstable. It may take multiple attempts and messing around with settings to get a full render of your animation.

Problem with this, evee motion blur looks good but all passes are not motion blurred :( even in v3.0.1 )