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Subdivision surface makes holes in mesh
I use Subdivision Surface modifier. Some edges I want to leave sharp. As you can see on the screenshot, this action adds holes to the mesh.

What is wrong here and how to avoid this?

First thing select all in Edit mode and press M to Merge by Distance, if it does not work please share your file

Seems no effect. Here is the original file - https://file.io/TCRvgpnIPPIw

Edge split is the second modifier, before the subdivision...

@Artem your link doesn't work, please check if lemon is right or share your file again

@moonboots Sorry, reuploaded - https://disk.yandex.ru/d/KVGG-FFxaXyv-A

@lemon "Edge split is the second modifier, before the subdivision" - yes

The holes are created by the Edge Split, why did you want to use an Edge Split exactly?

What you see is normal, you've given an Edge Split modifier to your object, by default it cuts the edges according to the desired angle between the faces, here you've enabled the Sharp Edges option so it takes only the edges marked as sharp into account. If you cut the edges and give a Subdivision Surface to the object it will round the edges and therefore it will show holes. To fix the problem, deactivate the modifier, or explain why you are using it in order to find another solution.

I'm a bit confused, how to make it without using Edge Split? Subdivision Surface ignores edges marked sharp - https://ibb.co/h7Cr05L . As far as I understand, I need to manually make small bevel for needed edges. Any other solution without breaking mesh? Also please take into account that I use old Blender version 2.79, because more recent versions don't work on my computer.

How to make what exactly? If you want round or sharp edges, bevel them and choose a width that fits your need?


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Smoothing artifacts on wheel spokes
I'm modelling a wheel and I can't get rid of these overhang artifacts where the spokes meet the inside of the wheel. I've spent 3+ hours trying to fix it to no avail. There has to be a way to do this.

Adding loop cuts to get rid of the N-gons fixes the issue,  but also ruins the shape of the wheel.

You need to get rid of those n-gons.
For that, you'll need way more evenly spaced edges to support the geometry.

Add more edges using Loopcuts. It will deform the geometry, but don't worry.
Select the individual circles, one by one.
Use Mesh > Transform > To sphere on each circle to smoothen it

If you share your mesh, We can check the topology and make some tests directly on the file.
In general try to:

use planar faces
do not use triangle or N-gons

Try to cut on the red line (and remove the edge that generates 3-gons) and add some loop on the yellow lines (it's not 100% clear to me where is problem of your mesh).

source: Stack Exchange

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

sort: votes


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Display problems??? Very jarring stretch effect when maximized

SO, what is this? I get this every time I maximize the blender window. It disappears when I "restore down" the window, but I don't like having to do that for the entire time I have to work on it. So how do I fix it? I really want to always have the window maximize, and this is just terrible to look at.

Possibly a hardware/driver problem. Intel GPU, I assume. Hard to tell without knowing anything about your hardware. Please read this to learn how you could help us to give good answers.

This is an issue with your graphics driver. Updating the graphics driver will most likely fix the issue. See T75683 for a similar report on the bug tracker.

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


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Blender 2.8 Texture color error

I made texture for box. But original texture (right) and imported texture on UV editor (left) are not same.
Why this color changing happens?

I finally find the solution.
Properties editor -> Render -> Color Management
Changing the 'View Transform' to make post-render filtering.


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How can I achieve this smooth normal map?
Title is abit misleading. Couldn't find a good title that describe what I wanted to ask. I recently bought substance indie pack and while watching painter tutorial, I noticed something that I don't know how to achieve in blender.
(Apperantly I can add one image because I'm a newby)
The first is this crate and as you can see polygon count doesn't look that high:
The second is how it looks in substance:
And the third is the model before the tutor added normal map for this object:

My Question
It looks really smooth. When I try to create a height map from high poly to low poly, it's never this smooth. And more over, as you can see the second image looks like height map but the tutor clearly indicated that was a normal map(also added AC as well). Well to simply put, how can I achieve this in blender?

related http://blender.stackexchange.com/questions/2936/creating-game-models-for-android/2937#2937

Please show us your normal baking results. The "unsmooth" one and how it looks like. It's impossible to tell what you are doing wrong otherwise. The question is very broad.

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


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Blender mirror problem
I'm trying to mirror an arch and then subdivide to get a smooth look but vertices that should be merged in the process do not behave as I would assume. I cannot subdivide and moreover, shading gets distorted.
Here's a youtube video: https://www.youtube.com/watch?v=w3lguvtfWr0
How can I apply this mirror modifier so it works normal?
PS:blender 2.78a

Issues are not sourced by the same but one of the answers helped me. Mesh had face where mirror modifier merged the vertices. I deleted the face and problem solved.

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


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Imported Objects and UV Maps
ok so here is what im trying to do, making a building with static props. while i was creating the props such as supports and so on, i started thinking about the uv map and about the major pain it was going to be managing the buildings geometry and the static props. A thought i had was that i could create the props outside of the current building file and import them in, but my question is, will they come into the file with their own UV map(where i can maintain the uv map only inside that file) and textured or will the model that is imported come into file expecting to be placed on the same uv map as the building.
Also to note, no i know that i could create the props outside and implement them into the building but what im trying to do is make a single object that all it needs to do is be placed and have all the props associated with it already placed

When you import an object from another .blend file with Link or Append from the File menu, it comes with all linked datablocks, so UV maps, materials, textures, and various others will be also imported.
When you import from a different file format with File > Import, what you get depends on what the format stores. For example, "Wavefront (.obj)" can contain mesh, UV map, and texture, but not armature. When you import an SVG file, you will get several curve objects.
For an example of using multiple .blend files in a project, look at the files from Big Buck Bunny.


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Trying to make multiple actions with different durations
So I made two actions on a single armature (to which is attached an object), one for running and one for walking. Now, when I play one and adjust the playback time (timeline, I guess) thingy it plays nicely but the other one doesn't get to play all the way. I hope you know what I mean. So my question is: how do I make multiple actions that have different a duration on a single armature


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No animation in Fluid Simulation
I work in version 2.82. I have a problem with mantaflow fluid. At the stage of preparing the file, after setting the settings - I can not play the animation of the water. When I click play, time starts to run, but the animation of the water does not appear. A similar problem was with special mantaflow version 2.79. I did it on several different tutorials, the problem is always the same - there is no animation. How can this problem be solved?

Make sure your FLOW object is fully inside of the DOMAIN Object.  If it is not, nothing happens.

To my knowledge, this is a bug that is fixable using this method:

Select the Domain object
Go to the Physics tab
Change the Resolution Divisions by 1 digit
Replay timeline from the beginning

No idea why this happens, but it does.


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How to remove sound from sound spectrum in animation nodes?
this is infuriating. Even if I delete the sound spectrum node, even if I restart Blender, the sounds that I loaded into sound spectrum node will remain there to be played simultaneously. How do I clear that node from previously loaded sounds?

When you load sound file in sound spectrum it will automatically appear on video sequencer.
You can remove audio from there.

Wow Hari, I kept looking everywhere else. Thanks mate, thanks a lot!


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What would be the simplest way to create a vertical or horizontal cell fracture / realistic wood break?
I want to create a piece of cracking wood in blender for a project of mine, I made a blender-guru esque ball n' chain destruction setup, made a simple cell fracture wall, put a wood material on it, and that was it, but its pretty bad
This is NOT how wood should break.

What im trying to do is create that wood "sharding" effect. Is there a good method to do this in blender 2.8? I found a tutorial for an older version using cell fracture, and thats better, but its not what im going for, it still looks like a piece of metal or concrete: https://www.youtube.com/watch?v=w_m81zF9WtY

Try some more extreme scale settings in the cell fracture addon, such as 1.0, 1.0, 0.1. Here's an example of how that looks.

@gandalf3 Thankyou, ill check some things out


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Why do these "Black Blobs" appear within very tiny spaces in blender?
I have a shader which uses a massive array of planes mixed with a transparent BSDF to render 3D / Procedural textures, such as this marble fractal..
However, cycles appears to render these odd "black blobs" inside the center of the planes.
This doesnt just happen with my 3D texture, just having a transparent array of planes creates this weird internal blackness.
Ive seen people use this technique before.... so I have no idea why its suddenly not working, it used to, but now its creating these weird black spaces.

In the Render Properties tab, under Light Paths > Max Bounces > Transparent. Increase the max bounces for transparency.

EDIT:
I just realised you have 400 planes with transparency which is excessive. Im assuming you havn't used volumetrics before. So instead of faking volumetic shading, use real volumetric shading instead.

Volumetrics wont work for this high level of precision (An extremely high detail marble fractal), its the reason Im using an array of planes. Also, I needed even higher precision, and the max bounces (1024) isnt enough to fully erase the black bits, so I might just edit the source code and let me bypass the limit. The cloudy appearance of volumes just doesnt work for what I want to do.

You can increase the volume step rate in the render properties. Also set the max volume bounce to 1. You can get pretty sharp results. These are 2 cubes, one rotated , both with different procedural volume shaders. https://i.sstatic.net/J9c0K.png @MisterSirCode

Alright, I might give it a shot, thanks


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Is it possible to create a Gaussian Pass Filter in Material Nodes?
I noticed someone did something of an image kernel here: https://blender.stackexchange.com/a/52326/94245
I was wondering if something similar is possible with a gaussian kernel to achieve TRUE gaussian blurring in material nodes?
I want to be able to blur noise textures and similar vector data.
So far the best Ive seen is using white noise and other such data to get "close" to gaussian, but more of a "noisy" gaussian (Credit to jocafa for the nodes)


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Is it possible to add custom nodes to the material editor?
I noticed the addon for the Renderman Render Engine for Blender added its own custom nodes for shaders.
I wanted to know how I can do this, and write my own python code for them.
For example, I wanted to create a node that would take in 2 values, and depending on a condition, return either. (like an if statement)
Im quite new to python and add-ons in general, but I already have some experience in python, I just wanted to know how to create my own nodes.
Where in the API should I be looking..

I believe you can't actually add new nodes via a python addon: you would need to write a new one as part of the cpp code and rebuild your own version of blender. another option could be using OSL to make custom nodes (https://docs.blender.org/manual/en/latest/render/shader_nodes/osl.html)

You could also set up node groups that python can instantiate. This has been done with things like material library VX.

Try dissecting the blend file in this answer, be sure to upvote if it helps - https://blender.stackexchange.com/a/223815/110840

@person132 Renderman Blender addon added its own custom nodes. It doesnt use a custom install, its just an addon.


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Translating a Sub-Surface level color onto the surface of a mesh?
So ive been using Signed Distance Functions in rendering recently....
And I wanted a really efficient way to make custom shaders for the SDFs themselves and render them very quickly...
I wrote a raymarching engine within blender to start applying my effects... But Ive realized that for some reason, I cant translate the 3D position of the SDFs in the raymarcher...
It renders the SDFs as a surface shader... so it uses the vertex color on the surface of the cube, not the SDFs inside...
So using a stack of planes, I can estimate what it SHOULD look like:

And this is fine and dandy.... but its a terribly inefficient way of rendering SDFs, and its incredibly slow / memory intensive...
meanwhile, a raymarcher is many times faster and more efficient.
Sadly the raymarcher uses the surface as points.... so when I plug in my colors, it overlays the colors on the host shape's surface (its a cube)
So it results in this horrid output:

What I want to know is, Can I take the output positions of the SDF and render the color at that location on the surface of the cube? So that way its using the internal color, not the surface color...

I think I understand what's your issue, and I'm not sure how you implemented your SDF. but in the end you display the surface of the SDF anyhow, so only the surface color should suffice(?). anyhow your issue might be to due of geometry, a quick and dirty fix could be to subdivide the cube. you could try adaptive subdivision for efficiency. otherwise more info about your implementation would help

@HananBeer Theyre Signed Distance fields, theres really only 1 way to implement them... Calculating distance. I just use vector math. The file is available here if you want to use it, its the SDF Library blend file. https://github.com/MisterSirCode/Blender-Utilities

As for the surface color, it doesnt use the surface color. Theres no meshes. SDFs are just math. And blender supports 3D vectors in shaders, so the SDFs are far under the surface. The slight blue and red you see on the surface of the cube is a result of the SDF's Distance. Its always blurry / like a gradient until you use a Greater Than 0 node, which turns it into a flat shape with sharp edges.

You had your SDF connected to surface, that's why. I connected to volume and it seems to be the desired result.

Its raymarching... not the volume

Also that layer node is only meant for a stack of planes.
SDF Volume plugs into volume

SDF Raymarch is what Im trying to fix right now... I cant color the surface of the SDFs correctly in the surface renderer


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Is it possible to voxelize a volumetric shader using geometry nodes, or create volumes in geometry nodes?
Using math or signed distance fields, I can create 3D shapes and 3D Fractals using volumes in shaders.
This is convenient and all, but the detail and style is limited, its also very slow, and it doesnt work in eevee.
I want to know if its possible to capture the volumetric data from a material, and convert it to a mesh.
Or, if thats not possible, is it possible to create math-based volumes or 3D fractals in geonodes?
I found this node, but upon plugging in a basic SDF into the density, it went red, so Im assuming it can only take attributes or something?? (I really dont know how to use geonodes)
Ive seen people create points in geonodes based on math before, so I had hope for this, but Im not sure.


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Is there a more accurate way to do booleans with geonodes?
I have a technique to do better fluid / glass interaction in blender... shown below:

This is all fine and good, but its somewhat of a pain in the ass to setup, since it makes use of booleans and flipping normals and other things...
This shouldnt be all that complex to reproduce in geonodes. My issue though, is that the booleans used in geonodes are shit. I dont mean that as a mock... Theyre literally terrible.
Any basic operation causes a mess of vertices and faces...

With normal booleans, usually swapping to fast fixes these kinds of issues... From what I can tell, it appears that geonodes is using the "exact" booleans from the modifier... Theyre usually terrible in my experience..
Is there any way that I can use the "fast" booleans in geonodes, or is there some better alternative? I cant even do basic intersections without completely breaking the mesh.
This technique for fluid interaction has to be perfectly precise... and the "exact" booleans are, funnily enough, never exact... they always break.

In my experience the "exact" method in booleans works really well with perfectly manifold meshes. Did you make sure your meshes are manifold ?

@Gorgious yes, theyre manifold


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Obtaining the current object rotational coordinates with OSL or Nodes? (No drivers)
Im writing a fake pleochroism shader for a project.. I need to know the rotation of each "crystal axis" (the object's euler coordinates basically)
Right now Im currently using a driver to sample the rotation and feed it directly to the script via a combine xyz node.

The driver pulls directly from the object properties. (it automatically puts them in radians when the driver outputs to the shader editor)

This is NOT an optimal solution. Youd have to declare custom axis for every single isometric crystal and its rotation.... I want something that can be automated / calculated per object based off its internal properties..
From what I could tell on blender's site, theres no attribute or builtin property to reference the rotation... only location.
Im sure theres a mathematical way to get the rotations with the local and global position, but I dont know how I can do that honestly.

One way to acquire the object rotation, without the use of drivers, is to use geometry nodes:

I am reading the XYZ Euler rotation of the object, in radians, and outputting that as a vector attribute "rot"; I can then reference that attribute in my shader.  Because I am reading the "original" object rotation rather than the "relative" object rotation (which would be zero), I am getting the world space rotation, which may or may not matter for your purposes.
This can be built into an existing GN modifier.  Modifiers can be copied easily to any number of objects by link/transfer data -> copy modifiers.

I was more looking for a way to it within OSL, so I can make the material self-contained, but thanks still.
It seems blender just cant do what I want right now.


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Why is the liquid in my liquid domain not touching the edges?
I am trying to get a fairly simple liquid "splash" effect, but I'm getting very confused because I don't fully understand how this system is supposed to work and every video/tutorial appears to be for a different version of Blender (I'm using 4.1.)
I have a Liquid Domain object and within it I have a simple disk which is configured as an Inflow source like this:

My domain object is drawing the particles (using the Particles > Spray option) - it's base configuration is like this:

However when I try to run it, the liquid does not appear to come from anywhere near the source, appearing down in the bottom half of the domain object, and then it seems to slosh around but miles away from the edges of the object, as if it's in a cube half the size of my domain object.

What is going on here? Why isn't my liquid going to the edge of my Liquid Domain like it seems to do for everyone else?

I'd try to set the origin of the source to its center, and also check that the dimensions of the objects are comparable to the gravity value.


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Why is my smoke animating on preview but not on render?
I am trying to do a simple smoke simulation using the Quick Smoke effect and the problem I am running into is that although my smoke shows and animates fine on preview, when I start rendering it just stays still, a big smokey blob around my emitter object. It appears to be simply rendering Frame 1 of the smoke in each frame.
I have tried to bake the animation in my Smoke Domain and my Emitter object ( because I don't honestly understand which is the one that 'owns' the smoke in this regard ) and save the project afterwards but that didn't change anything.

This is the only frame that appears to get animated. The behaviour is the same between Eevee and Cycles so I assume it is something I'm doing wrong.
My smoke domain looks like this:

What do I need to add or change in order for my animation to behave the same way in render that it does in preview?

Set it to Modular/Final and bake it again. Replay bakes everything live.

@Yohello1 if you make that an answer- perhaps with a bit of explanation of why - I'll accept it.

Sorry. I usually do comments and don't often do answers because most people are looking for a fix not a for the reason why it happened. Tell me if I need to add any more.

I've been using various SE sites for a long time and I know someone else will run into this problem sooner or later so a real answer will help them as well. You solved my problem and you definitely deserve credit for it. Thank you.

This also apply's to fluid simulation. Do not change the file format it will cause more issues than you can count
There is one key reason why it will not show in render(Don't worry all the settings are fine) the reason is the "Type" under cache is set to "Replay".
The type replay is typically used for quickly making smoke simulation and finding laws quickly and will bake while the animation is playing in view port. But this is not like the old smoke simulation engine where just playing the animation thing in view port will bake it properly and save it to disk. Because the simulation data is not saved to disk when you go to render it it will have no information about where the smoke is or anything about it (you can say it's in ram but Blender won't use that). Therefore it will render nothing or the same data as the last one used(last frame con occur due to other things) it will normally render nothing.
There is an easy fix for this to set the Cache type to Modular ,or Final.
Modular = Independently bake everything, bake the smoke then the noise then anything else
Final = Bakes everything at once for this one simulation, I do not suggest using this because one issue in the actual smoke simulation can make you bake the entire thing again
Do not change the file format

https://blender.stackexchange.com/questions/161000/how-does-fire-and-smoke-simulation-work/161031#161031
old forum with some other info if needed


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In Blender 2.8 how do I render the world once for all view layers?
I have a setup where I have one collection that is a background and one that is silhouetted against it. Each of these is in it's own View Layer. The background one rendered straight, the foreground one is lit brightly, rendered and then inverted.
My World is a starfield generated from a noise texture. The problem is that if I have world enabled, the inverted foreground layer creates an inverse starfield, completely blanking out the background layer.
I have found a few questions around this topic ( for example 'One render layer with background image and one with transparent background' ) but they are old and they talk about enabling environment rendering which doesn't seem to exist any more.
So, in Blender 2.8 how do I render my world once rather than once-per view-layer?

The principle is the same. Create a new View Layer, disable all collections (right-click > View layer > Disable from View Layer) and render. For all other layers set Film to transparent...

@brockmann then combine at render using alpha-over?

You can get precisely what you want by creating a dedicated, empty background render layer with an environment pass.
1.) Under "Render properties" on the "Film" panel select "Transparent". All of your current layers will now render a transparent world background.
2.) Create a new layer and disable ALL collections in the Outliner. In the "View Layer Properties", enable an environment pass.
3.) Now in the compositor, use an "Alpha Over" node to put everything above the "Env" channel of the background layer we just created.

You could use scenes instead of view layers, render, and combine; with scenes you could also use a different render engine.

If you have doubts you could watch this video https://vimeo.com/346386958


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Why does my rendered video not animate?
I have used Blender to generate a video clip using H264 and the clip works perfectly, however I need to add audio and some titles, so I have re-imported the clip into the video editor and added the other elements there.
The problem I have is that when I export the video, it is not animated. What is exported appears to be a single static frame rather than the animation that is visible when one opens the clip in a regular video player. Unfortunately the clip is not highly mobile, it changes quite gradually, so it isn't very obvious in the preview, but it doesn't look to me as though the preview is animating it either.
I'm wondering if there is something wrong with the time selection, but I can't figure out what is wrong with this:

I am completely new to the Blender-as-video-editor world so I might be missing an essential step, but like most matters for the Blender noob, I have no idea what that would be because the interface has ten thousand settings and every tutorial or document is discussing a slightly different version.
What do I need to do to ensure my video is rendered with animation rather than static?

You should add the audio and texts to the original edit, or you'll lose image quality.
(If the file is not playing properly in Blender it may be because it is too heavy for fluent playback, or it is corrupted. You could try to export it again from Blender in some other format)

After struggling with this for a while I switched to a different video editing tool ( I used KDEnlive ) and used that to put together the complete video. It worked perfectly with Blender's exported video and was quick and easy to work with. A Swiss army knife is very practical when you don't have a screwdriver, but if you do have one, use that instead.


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Drawing 2D lines
In this tutorial a guy draws a 2D portrait in Blender: https://www.youtube.com/watch?v=ooKF4hxjaSM
The only way I can find out how to do it is by creating a Bezier and modifying it. It works but it's difficult comparing to how it works in other software.
Is there any way in Blender to just add vertices in 2D (in ortho top or side views) so a line is automatically drawn between them? It looks like this guy is doing it..

Easy and fast : ( if you have a graphics tablet )

Use the Grease pencil to draw
convert it to a curve

slower method :

Create a dummy object
Switch to Edit mode and delete everything
switch to the appropriate view in Orthographic mode
Keep Holding Ctrl and LeftClick where you want to add the next linked vertex
( the new vertex will be connected to the last selected vertex )

and the guy in the tutorial is supposedly doing the second method?

@Bart yes he is ( you can set a background image to trace along )

It worths noting that in the video each object has the Caltmull-Clark Subsurf modifier to automatically smooth the final strokes.

He also uses a mirror modifier to duplicate the work to the other side. Note that he uses BI and very briefly at 1:46 you see him set the material type to wire to make it visible in the render.

Change the bezier curve segment [Set Spline Type] to poly style.
To extend a Bezier Curve
You may select the last point then press control click.
Alternate
For getting straight line segment
If you create a new curve in edit mode. Completely select that curve or portion.
Scale X 0 (zero) .... which ever axis is best.


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Couldn't get the right coffee color and the thickness of glass cup
I was trying to follow the coffee cup tutorial by Blender Guru on https://www.youtube.com/watch?v=fdWUjEMzDhg&t=235s
However, I have two major problems with my own project:
1， I couldn't get the right coffee color changing the "Color" and "Density" in Materials -> Volume (Volume absorption), I've also tried changing Base color in Principled BSDF but I got nothing close to real coffee color. Both colors don't work the way I thought.
2, There's no gap between liquid and the cup outer wall (no thinkness of the glass cup).

Blender file attached[link]https://drive.google.com/drive/folders/11vxhEN6v368mkW5bhWUFZB5ix18kMqVt?usp=sharing

The glass is supposed to work this way with the Principled, if you don't want this kind of glass you should use a mix of nodes like Glass, Transparent and Glossy. Your coffee seems ok as well

I would try to use mix nodes to give some thickness to the wall, but the color still look a bit off from my own perspective. Thank you for your advice!

I will give a try

I've given a try for the glass material, it's not completely accurate but in my opinion it creates the illusion. I haven't changed the coffee material itself.

Thank you for this great contribution! By looking at the picture, the color of coffee looks much better and the thickness of the glass is indeed expressed. I will try out in the weekend (will update)


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(Blender 2.82.1) "Could not build proxy for strip ..." How do I fix this?
I'm using Blender 2.82.1 on windows. When I add a video and try to rebuild its proxy and timecode at 50%, I receive an error message "Could not build proxy for strip ..." This was not a problem before. I tried uninstalling and reinstalling blender, but didn't work. How do I fix this?

Same here, no explanation, just "can't do it" I tried to re-encode the clip just for kicks, but no ; looks like proxies are broken :(

This solution worked for me and may be helpful for others too https://www.blendernation.com/2020/05/30/edit-4k-video-using-blenders-vse/

I had similar issue with the following file: "30 ans laura.mp4"
I renamed the original file to: "Laura.mp4", reimported it and it worked.
I suppose it's an issue with the numbers.
I didn't investigate further but I hope it helps.

I had a similar-ish problem when building a proxy that I'd already made but wasn't working.
To solve it I deleted the proxy folder (where blender keeps its proxies) in the video source folder (where the clip was) and now it works.
Maybe Blender is already seeing a proxy with that file name somewhere in your system and that's causing a problem, and also why renaming the file worked for the other answer.


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How do I convert a material output from the node editor into a png image file? Blender 2.82
I combined an image texture with a noise texture in the node editor and I just wanted to know if you could export both the image texture and the noise texture as a single png file.
Can you?

Hello :). Sure you can, it's called texture baking. https://blender.stackexchange.com/q/13508/


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No active image found in material even though there is an image texture in the material
I've tried replacing the image texture node. I've tried removing it and re-adding it but it still gives me the error that there is no active image found in material. Is there something I'm missing?

what we see is probably the Musgrave texture plugged into the Roughness, is that your question?

obviously, as seen in bottom left, the texture does not exist.

I just saw that. Thank you lol.


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How do I get even lighting across a model? Blender 2.82
I want to texture bake, but the lighting causes the final product of the bake to be affected with dark areas. How do I get even lighting across the model or fix the problem in general?

Can we get some visuals?

Turn up the value of the world's color.
Say we start with some object that I have a few lights on, but in an otherwise empty scene;

I turn off my collection of lights, then make the color of the world shader pure white;

Result;

To get even lighting across your whole model you could use a very big plane with an emission shader, so the shadows will be minimized. Or you use a hdri-Environment with just a white image, so it creates an even light-dome around your model. Another solution could be just one color solid white for the environment. All the best Marco


text:
Weird anomalies on multiple material texture baking
I am new to blender so bear with me.
So I've been testing baking textures on models with multiple materials and it usually goes fine but this time after the bake was completed there were weird anomalies on the finished texture. Some parts were brighter, some parts were completely colored wrong and I don't understand why.
I have the blend file here: https://pasteall.org/blend/7fd1e2824ec6469585b849ee35db8a60

Hello, you don't share your high poly nor your normal map, but I see that you have custom split normals, maybe your problem comes from here? Object Data > Geometry Data > Clear Custom Split Normals Data

@moonboots YEP that completely fixed the issue. Livesaver. Thanks a lot :)

You have custom split normals, which can happen with imported FBX, it causes weird shadings, go into Object Data > Geometry Data > and press on Clear Custom Split Normals Data.


text:
How to copy a property definition (including list of possible enum values, tooltip description, etc.)?
I want to write an operator that allows to quickly add and properly set up action constraints on all the selected objects simultaneously.
The operator should have some of the same properties as the action constraints themselves. When the operator is called those operator-properties should be set in the invoke function or via the redo panel as usually. Then in the execute function of the operator the values of those operator-properties should be copied to the corresponding properties of the action constraint of each selected object.
For example action constraints have a property called transform_channel. And my operator should also contain a corresponding property transform_channel whose value will be copied to the corresponding property of the action constraints. The transform_channel enum property of my operator should have the same list of possible enum values as the corresponding property of the action constriants, that is:
'LOCATION_X', 'LOCATION_Y', 'LOCATION_Z', 'ROTATION_X', 'ROTATION_Y', 'ROTATION_Z', 'SCALE_X', 'SCALE_Y' and 'SCALE_Z'
Also ideally the tooltip (=description) should be the same.
My question is: can I somehow avoid explicitly copying those enum values and the tooltip from blenders action constraint into my code? Because this feels somehow redundant in my opinion.
The redundant version which I do not like looks something like this:
import bpy

class ActionToConstraintOperator(bpy.types.Operator):
    bl_idname = "object.action_to_constraint"
    bl_label = "Linked Action to Action Constraint"
    bl_options = {'REGISTER', 'UNDO'}

    transform_channel: bpy.props.EnumProperty(
                            name="Transform Channel",
                            description="Transform channel from the target that is used to key the Action", # <-- How to avoid this redundancy?
                            items=(
                                ('LOCATION_X', 'X Location', ''),   # <-- and this?
                                ('LOCATION_Y', 'Y Location', ''),   # <--
                                ('LOCATION_Z', 'Z Location', ''),   # <--
                                ('ROTATION_X', 'X Rotation', ''),   # <--
                                ('ROTATION_Y', 'Y Rotation', ''),   # <--
                                ('ROTATION_Z', 'Z Rotation', ''),   # <--
                                ('SCALE_X', 'X Scale', ''),     # <--
                                ('SCALE_Y', 'Y Scale', ''),     # <--
                                ('SCALE_Z', 'Z Scale', ''),     # <--
                            ),
                            default='LOCATION_X'
                         )

    def execute(self, context):
        for obj in context.view_layer.objects.selected:
            constraint = obj.constraints.new('ACTION')
            # [code to add proper action data block and constraint target object
            # not relevant for this question]
            constraint.transform_channel = self.transform_channel
            # similarly for other properties like target range min/max and action range start/end

        return {'FINISHED'}

    def invoke(self, context, event):
        wm = context.window_manager
        return wm.invoke_props_dialog(self)

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

def unregister():
    bpy.utils.unregister_class(ActionToConstraintOperator)

if __name__ == "__main__":
    register()

Basically I would rather like to have a code that looks something like this (but that does the same thing):
import bpy

class ActionToConstraintOperator(bpy.types.Operator):
    bl_idname = "object.action_to_constraint"
    bl_label = "Linked Action to Action Constraint"
    bl_options = {'REGISTER', 'UNDO'}

    transform_channel: bpy.props.SimilarEnumProperty(bpy.types.ActionConstraint.transform_channel)

    def execute(self, context):
        for obj in context.view_layer.objects.selected:
            constraint = obj.constraints.new('ACTION')
            # [code to add proper action data block and constraint target object
            # not relevant for this question]
            constraint.transform_channel = self.transform_channel
            # similarly for other properties like target range min/max and action range start/end

        return {'FINISHED'}

    def invoke(self, context, event):
        wm = context.window_manager
        return wm.invoke_props_dialog(self)

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

def unregister():
    bpy.utils.unregister_class(ActionToConstraintOperator)

if __name__ == "__main__":
    register()

Unfortunately a function like bpy.props.SimilarEnumProperty() does not exist in blenders API as far as I know. I just made this up to demonstrate what I want to do.
(I think I have already found a solution to this question, which I will post in the answer section. But I like to know if other people will agree with my answer or if they find better solutions.)

In an answer to a different question I learned that there is an attribute called bl_rna that apparently allows to access the list of possible items of enum-properties.
I did not find a proper documentation on this bl_rna-attribute in the official Blender Python API Documentation. But still with some experimentation I came up with this:
import bpy

class ActionToConstraintOperator(bpy.types.Operator):
    bl_idname = "object.action_to_constraint"
    bl_label = "Linked Action to Action Constraint"
    bl_options = {'REGISTER', 'UNDO'}

    transform_channel: bpy.props.EnumProperty(
                        name=bpy.types.ActionConstraint.bl_rna.properties["transform_channel"].name,
                        description=bpy.types.ActionConstraint.bl_rna.properties["transform_channel"].description,
                        items=list(map(lambda id_item: (id_item[0], id_item[1].name, id_item[1].description, id_item[1].icon, id_item[1].value),
                                        bpy.types.ActionConstraint.bl_rna.properties["transform_channel"].enum_items.items())),
                        default='LOCATION_X'
                    )

    def execute(self, context):
        for obj in context.view_layer.objects.selected:
            constraint = obj.constraints.new('ACTION')
            # [code to add proper action data block and constraint target object
            # not relevant for this question]
            constraint.transform_channel = self.transform_channel
            # similarly for other properties like target range min/max and action range start/end

        return {'FINISHED'}

    def invoke(self, context, event):
        wm = context.window_manager
        return wm.invoke_props_dialog(self)

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

def unregister():
    bpy.utils.unregister_class(ActionToConstraintOperator)

if __name__ == "__main__":
    register()

I could also access the default value with bpy.types.ActionConstraint.bl_rna.properties['transform_channel'].default. But for some reason this gives me 'ROTATION_X' while when adding a new Action-Constraint the value of transform_channel actually seems to be 'LOCATION_X' by default.


text:
Why imported textures from Substance Painter looks wrong in Blender?
I baked high poly meshes' details into low poly meshes and textured them in Adobe Substance Painter. When I import the textures back to Blender, it looks different. It seems that the problem comes from the metallic map. How do I fix this?
Files

Edit: I took a second look at your normal map texture which was disconnected in your file and it seems that your bake has gone wrong. We can see the ugly geometry around the key's hole. I don't think that's how it was supposed to look.

Aside from that, ticking [x] Auto Smooth still stands.

Shouldn't the smoothness come from the high poly mesh? Also, it doesn't fix the problem.
https://prnt.sc/CPtksXR-w0da

@melly_berk Edited my answer above. As for that smooth key part, you can turn down autosmooth to like 18° or something and the edges should become visible.

@melly_berk I just imported the low poly into Sbs Painter and put your normal map on it and it looks like it has the same issue as blender. Let me know if this helps.

Well, from all those tutorials that I watched online, I thought you were supposed to not use auto smooth for the low poly because the smoothness should be baked from the high poly, it's just not the case it seems, auto smooth seems the solution. Thanks.

@melly_berk those tutorials could be right. Anyway don't give up on baking normals, autosmooth is just a band aid on your problem. Maybe you need to tweak some baking settings. Hope you figure it out.

@melly_berk no those tutorials are wrong, or you might be confusing AutoSmooth with SubDivision Modifiers. Autosmooth is meant to be used to preserve clean normals in the low poly by splitting the vertex normals where the angle exceeds a certain threshhold.. The problem in your mesh is actually coming from relying too MUCH on the high poly to smooth the normals. Make sure your low poly at least has smooth edges on the uv seams, if not more where they might be needed (usually a setting between 30 and 45 degrees works fine) and your bakes should come out looking alright.

@Jakemoyo I'm still having problems with baking normal maps. This guy-> https://www.youtube.com/watch?v=8W7txa9ltBw and this guy -> https://www.youtube.com/watch?v=bpx4QxuetNs didn't use auto smooth. They also didn't export painter textures back to the Blender, (I assume if they did, they would have the same problem that I did). I'm just lost.

Okay, the first video doesn't set auto smooth because his mesh is so simple that shade flat is the same as AS. The second video belongs in the garbage, that guy has no idea what he's doing. Take your mesh, shade smooth, then enable auto smooth and set the degree to like 45. Then go into edit mode, run Select all Sharp edges to set all edges at 45 degrees to be seams. It's important that the sharp edges in auto smooth also have UV seams or you'll get bake errors. Then unwrap it with those seams. Then bake it. That should do the trick.

Read these posts 1 2 as many times as it takes to internalize the info.

@Jakemoyo You're a diamond mate! Thanks for the help.


text:
How to create this rhombus shape
Can someone teach me how to create this rhombus shape procedurally (not geometry nodes) or link a greate resource so I can learn it from?

Any way of generating rectangular cells with distance-from-edge would do. Then you can rotate the texture, and scale after rotation. (That means the inverse of that transform on the space the texture is measured in.) Here, being lazy, and using a zero-random 2D Voronoi's 'Distance From Edge'..

Using Float Curve to shape the height profile
Cheating, by shading the grooves with a darker tint. This may not be needed in different lighting conditions, or if using displacement rather than Bump, as in this example.

Nice - float curve - I never would of thought - my method instead was to pull my hair out trying to find the right grayscale balance that both brought out the grooves in a somewhat ill-defined manner, whilst nor simultaneously destroying the overall shape of the "diamond peaks" - all without visual nodes in the shader graph - how is it blender doesn't have this feature yet?

Hi @ChristopherBennett !  You used to have to use RGB Curves  to do that sort of thing.. Haven't I  seen visual nodes, somewhere? Was that an Add-On, or a branch, or have i just gone doolally? I've just got used to shift-clicking bits of my tree..  it would be nice, though...

You've probably seen it lots of places - Unity, Unreal, Substance Designer, even obscure engines like Godot do have, and have had, a visual graph for a many years now. There probably is some hard to find, paid addon that might create something of that nature, but I think given how far blender has come, it deserves to have it come stock. It's in my "wish bag" of things I wish blender had. ;)

Found the addon - https://blendermarket.com/products/node-preview?ref=236

@ChristopherBennett Ahh! That's the one. I saw it in its free-preview days.

Try something like this - it's just a couple of Wave Textures, tilted at a 20 degree angle and mixed together. I used the original textures for the mix as well as adding some "highlights" with the color-ramped sections to make the "grooves" more defined - the "dark" end of the color-ramps are not black, but a lighter grey (not sure that's clear in the photo.) At the end, I added some "Grunge" from a Noise Texture to make the surface more bumpy:


text:
Adding contact shadows on glass table
There are no shadows that indicate the objects are on the top of the glass table.
How can I add shadows?
I'm using Sun and an Area lamp on Cycles.
This is the glass material that I've used from online:

The closest I was able to personally achieve that resembles your setup is below. It isn't perfect - it changes the look of the glass a little, and requires some very bright, or very close (or both) lights to be properly visible. As you can see from the image, I had to put the area light close enough that the light is glaring off the surface of the glass. It also seems that as is usual, the smaller the light radius, the better for the shadow. Therefore, keep the size of the area light as small as possible, and even consider swapping the sun for something else maybe even a very bright point light). However, one thing that works well in your favor is that the shadow shows up best at a shallow angle (like the one in your photo) so you can probably get away with less bright lighting. Also, the change in appearance of the glass shouldn't be as noticeable because the glass you are using is very thin. Regardless, have a try and see if it works, or at least gets you closer.


text:
How to fix face orientation when using screw modifier
I'm trying to model a camera lens using vertexes and screw modifier like spline modelling.

But face orientation is fully red and that becomes a problem when I try to use a boolean. Recalculating normals won't work because there are no normals to recalculate.

So are there any ways of solving this without applying screw modifier and then recalculating normals? Thank you in advance.

There are two ways to do this.
Click on the flip checkbox in the modifier settings

Set the angle to -360d


text:
No shadows with Eevee, no render with cycles
This is my first time using blender in a very long time and I'm trying to make a render of a board game I'm working on. I believe I have everything set up correctly but when rendering with Eevee don't get any shadows, and when rendering with cycles I get a grey screen. I don't know what's wrong with the cycles rendering but I think there's some sort of global illumination affecting the shadows in the Eevee rendering. Thank you in advance!

I just donwloaded your file and switched the render engine to cycles, and the scene rendered fine.

there is definitely somethings strange about the scene settings, because in eevee, i deleted the light, and set the background color to black, and the scene was still fully illuminated.

I downloaded your file, and there's a shadow in both cycles and eevee. I could comment it but my rep is <50. You could try to copy paste all objects from this .blend file, to a newly created with default settings and check if it's ok
eevee:

cycles:

Thanks, ahahaha

Thank you, that fixed the lighting! When I try to render with cycles I still get grey screen. Any clue as to why?

Have you tried adding another camera? Set it as active and try to render


text:
PNG alpha weirdness Eevee
Hey guys, my eevee render is sorta double-reflecting my PNG sequence. Is this a known issue?

Can you post either this file, or one like it (that exhibits the issue) using your setup? https://blend-exchange.giantcowfilms.com/


text:
how to change the texture of the material from polished to natural chipped
I have a picture of polished granite. I want to transform that material so that it looks like natural chipped as attached below. first of all is it possible if so how?
1) I tried creating a normal map of natural chipped but my reference image is very small so I cant use it on the larger surface without tiling
2) how do I transform the polished granite to look like a rough granite, I have no idea on how to approach this

You could do it procedurally:
Use 2 Noise nodes that you mix into a MixRGB (Overlay mode) node. Then you can add some glossiness or bumpiness, it all depends on the realism you want to give to your material...


text:
how do i indent into a cube to get such curvature

how do i create the above arch without those shabby polygons formations so its easy for UV unwrapping

is it a flat mesh?

Just to have it all in one place, Proportional editing works well too.
Set Falloff > Sphere and adjust size to your needs.

yes of course, it would be good to be able to create our own falloff though

Oh that would be one sweet feature :).

thanks that helped a lot !

You could start from a circle, delete the bottom half, stretch on the Z axis, extrude up and flatten on the Z axis with SZ0. To give it depth, extrude on the Y axis.

You could also do it with the Curve tool: Create a plane, subdivide it, select the 2 extremity vertices and the central vertex, right click (context menu) > LoopTools > Curve.

It will also work if you start with a cube.


text:
the cache in physics isnt accessible for simulation
 I am trying to learn smoke simulation however after selecting the object and doing quick smoke, the cache panel isn't being responsive in the physics tab for baking

You have to save the file once first, the cache-files will be written in a folder at the same locatation as the saved blend file.


text:
modelling a curvy tap
how do I make curvy surfaces(red) of the tap while having other surfaces very flat and hard(blue)?

here is a 2d diagram of it
I am sure that we have to use a deform modifier but how do i start?

Having round and flat parts is mainly matter of supporting edges (to make parts flatter than other).

Start with a circle (for instance 16 vertices) and extrude it up 3 times.
The first time as support loop. The second as bottom of the faucet and third for its top.
Then extrude the front faces part of the last extrusion, to make the faucet itself.
Close the top respecting quads (or almost).
Add a subdivision modifier (set it to 2, for instance).
Add loop cuts CtrlR (the support edges) and drive it to the edges you want to harden.
In this model, these supporting edges are the following:

Use an edge crease on the edges you want "straight" and then use a Subdivision Surface Modifier:


text:
bridge edge loops causing creases at the corners of my mesh
The corners are getting creased when I expect them to be smooth. how do i avoid this?

Enable the LoopTools addon, select your circle at the bottom of your mesh and right click > LoopTools > Circle, rotate it a bit on Z if necessary. Also, maybe you should use less faces to model your object, it would make it easier.

how can I model the mesh with fewer vertices without giving up on curve resolutions?

You could use a Subdivision Surface modifier, but if you can't for some reason, sure, what you've done is OK


text:
how do i make the inside concave profile of this basin

I am getting stuck on how do i approach this model.
My failed approach:

step 1 : created a cylinder with the given dimentions of the model
step 2 : tried to subdivide the face and failed
step 3 : tried to do something with lattice and still failed cause im not able to subdidve the top face

Is this what you're after? Not quite clear from your reference what the inside profile should be.

What exactly failed when you tried subdividing the top face? Can you show your current imperfect mesh?

YES!!!!! Robin Betts thats what i am after and how do i achieve it ?


text:
how do i model a pebble like sink
i want to model a sink like the goal attached below.
the top surface always seems to be flat, how do i get it to bulge like the target sink?
so here was my approach

added a cylinder and loop cut in middle
scaled and beveled the edge to make it bulgy
3)added an UV sphere and then subtracted it from the cylinder using boolean modifier

You should remove the top faces, select the 2 edge loops and Ctrl E > Bridge Edge Loops, you should also remove half of the vertical and horizontal edge loops to make it easier to model, then scale down the top edge loop so that it comes close to the shape

You should work with less faces, it would make things easier. You could begin with a 16/8 sphere, flatten it on Z:

Cut its top:

Extrude down its inner edge loop:

Extrude again and scale until you get the inner shape:

Bevel some edge loops in order to have a more accurate outer shape, etc:

Also slightly bevel the edge loops that you want to keep sharp:

your solution is perfect but if you look at the reference image, the cavity is bit skewed towards one side, how would that be achievable?

Yes you need to rotate the bottom, move some edges, etc


text:
How do i move these UV artifacts
I UV unwrapped the object properly. These stretch artifacts pop out of nowhere and are ruining my model with weird jaggered lines

The don't "pop out of nowhere" - the problem is your mesh topology.  See these vertices here, indicated in yellow:

Those vertices make the large face into a nasty n-gon, and so Blender has to add extra geometry to render it.
See for example this: Subdivision problem during modeling
and
Render shows geometry that isn't there. Normals?
To fix it, you need to connect those edge vertices to something, whether it's making more edges along the face or something similar.


text:
PBR maps required for polished granite
I need to texture a cube with polished granite. I applied my diffuse into the base color of the BSDF shader and set the roughness to 0. is that enough or do I need to add other maps like normal,AO and metallic?

If a polished look is your  goal, that should be sufficient, however, if you want photorealism, you might want to consider using a roughness map, so the surface isn't so perfectly "clean" - imperfections are the key to realism ;) Since the surface is totally flat, you shouldn't need to worry about normal maps or ambient occlusion either, and metallic is generally reserved for conductive materials (metals only),.

Since you're already using the BSDF, I would suggest turning the roughness way up (0.9ish) and adding "clearcoat" with a dirt map on the "clearcoat roughness" channel.


text:
Blender 2.8 can't find my intel gpu
I was following a tutorial on YouTube when I realized that in render mode GPU is clickable but does not work. I tried doing what i saw online but couldn't find my GPU in the system preference. The information about my PC is: Intel(R) Core(TM) i3-5005U CPU @ 2.00GHZ. And the GPU i'm using is Intel(R) HD Graphics 5500 driver with OpenCl 2.0 and OpenGl 4.4.

As mentioned in the other answer, this will not work, for the mentioned reasons. But even if it was to work, you have to remember that the GPUs that are built into CPU are generally very weak. You have an i3, so even weaker. I have an i5 and i7 and these GPUs built in are useless for the heavy lifting that is rendering on Blender or any other 3D App.
And: Even if you could make it work, it would be super slow.
Intel integrated graphics are fine for running a desktop, but not for heavy 3D work or number crunching like done with Blender with OpenCL and CUDA on AMD GPUs and Nvidia.
You are better off using the CPU itself, instead of its tiny little GPU addon.
But remember that 3D rendering work is probably one of the most demanding work you can throw at a computer.
I have scenes that I render that take 10 hours to finish, just one frame, on relatively powerful hardware.

Unfortunately your integrated graphics card doesn't fulfill the requirements for GPU rendering in Blender 2.8x. You would either need a

Nvidia graphics card with CUDA compute capability 3.0 or higher
AMD graphics card from GCN second generation or later

CUDA
CUDA requires graphics cards with compute capability 3.0 and higher. To make sure your GPU is supported, see the list of Nvidia graphics cards with the compute capabilities and supported graphics cards. CUDA GPU rendering is supported on Windows, macOS, and Linux.

AMD
OpenCL is supported for GPU rendering with AMD graphics cards. Blender supports graphics cards with GCN generation 2 and above. To make sure your GPU is supported, see the list of GCN generations with the GCN generation and supported graphics cards.
AMD OpenCL GPU rendering is supported on Windows and Linux, but not on macOS.

But the official website redirected me to this link https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units saying it works

@UnSpecificCoding I assume you're referring to the minimum requirements page? The Supported Graphics Cards section is for the required GPU for running Blender 2.8x. As noted below on the same page, GPU rendering has higher requirements. "These requirements are for basic Blender operation, rendering using the graphics card requires slightly different requirements."

@RobertGützkow no, he means the developer blog: https://code.blender.org/2019/04/supported-gpus-in-blender-2-80/.

@EricXue The answer is still the same though. Those are the minimum requirements for the GPUs in order to run Blender. GPU rendering has higher minimum requirements.


text:
Proportional edit mode can't be activated
Need to grab that selected vertex that you can see on the screenshot using "Proportional Editing". However, even though I activated this mode, every time when I press "G" and try to grab the vertex, the circle of proportional editing does not appear. Initially, there was a thought that circle is large a little bit so I was trying to use a scroll to make it more small, but there is not circle at all. How to solve this issue?

Hello :). Does proportional editing work when enabled through the Pop-up panel (where you adjust the distance)?

Hello! :) @JachymMichal Yes, it works. Actually, I have found what was the problem after you said about the Pop-up panel. I didn't pay much attention to that 3D cursor. It was displaced.

3D cursor should be aligned with the object you edit.

Hey :). That's weird. The 3D cursor should only matter when set as Pivot Point (which it isn't). Anyways, glad you got it working.


text:
How to create face between plane and cylinder objects?
Creating a 3D model of a vehicle, so I need to create faces between cylinder and plane object in order to form a fender of the car. Every time when I try to press F on my keyboard or select "New Edge/Face from Vertices", the command does not work. Please help me to fix this!

Those vertices belong to two different objects.
You need to join the objects into one, before you connect the vertices.
Object > Join, Ctrl + J

Wow! Thank you very much! It worked!

@NarimanMergalym Please don't add thank you as an answer, upvote the answer instead. If you feel it completely solved your problem consider marking it accepted


text:
How to wrap and boolean around a cylinder?
I am relatively new to Blender. I have faced the challenge during modeling a microphone. There is a specific pattern of grid that looks like a honeycomb. Actually, it was quite easy to create that pattern by using a circle. Then I applied a solidify modifier in order to create a volume. And I reached the point of wraping this grid around the main cylinder and putting holes in it. I tried couple of ways to make it happen by using Shrinkwrap modifier, Lattice, Surface deform, but the result was unsatisfactory. Does someone know another way to make the holes around the microphone? Thank you

@JachymMichal I think you already covered this topic, right?

Enable addon "Extra Mesh", it contains "Honey Comb" object. Create pattern of desired dimension and wrap arround with "Simple Deform" or "Curve modifier". With your current technique you will deal with bad Boolean topology. Related https://blender.stackexchange.com/a/99052/2214

You can use a Curve modifier to make your pattern turn around. Don't forget to put the honeycomb object at the exact same position as the bezier circle origin (use ShiftS for a Cursor to Selected then Selected to Cursor).

You could also use the Simple Deform modifier with Bend option. These methods will slightly deform each cylinder of the honeycomb object though, if you don't want that use another method like for example array around an empty (i.e. Array modifier with the Object Offset option)


text:
BUG? Particles offset from emitter when using object
I'm having an issue where the emitter particles are offset from the emitter geometry.  This seems to be a problem that's happened to someone at least once before way back in 2013 here:
https://www.blender.org/forum/viewtopic.php?t=27408
I'm having the same issue.  If I use "halo" as the particle, the particles emit properly from the emitter object.  If I switch to "object" they are inexplicably offset from the emitter object.
First image is the halo's around the orange highlighted emitter object.  Second image is the particles offset in the -Z direction from the orange highlighted emitter object.  The only change I made is switching from "Halo" to "Object" in the "Render as" setting.  My particle objects are 3-vertex cones.  Nothing complicated.  None of the other settings have changed.
I'm in Blender 2.81 on Windows.

I kept running into this. In my case I had to:

Apply all offsets to both the emitter as well as all objects in my particle group

Set the origin to the geometry of all objects in my particle group as well as the emitter

Took me a while to figure this out


text:
How to make glass shader?
New user. I'm trying to create a bedroom scene and can't get the window to be a glass shader.
See the image of from the Bender page on how to make glass. I think it is Cycles but I would like to also do it in EEVEE.

Hi, I just want to ask a potentially stupid question JUST IN CASE. Have you made sure that your material is actually plugged into the Material Output node to the right of your screenshot? The Group Output node won't do anything, and that's what's going on in your screenshot. Sorry to ask a silly question, but I only have your screenshot to go on and that's the glaring issue I can see.

Microsoft has reared its… oh, never mind.

shader should link to surface,not group output.

Hello and welcome. Please use a title that reflects the content of the question. It should be succinct, unique and identifying, and summarize what the issue is so that users can at a glance broadly understand what your post is about before opening it. Use the [edit] link below your post and avoid any emojis salutations or extraneous text not essential to the question. Remember, your title is the first thing potential visitors will see, and will weight heavily on their decision to open your question, which will directly affect the number of answers you might get.

What you did with the shader nodes should work in cycles. To make glass material for eevee, Create a new material, The material must be a principled BSDF node connecting to the material output node. Set the transmission in the principled BSDF to 1. Then enable screen space refraction in the settings of the material properties. Then go to render properties and enable screen space reflection and also enable refraction in screen space reflection. You can also lower the roughness to see more clear through your glass, it is your choice how clear you want your glass to be.To change the color of your glass just set your color in the base color of the principled BSDF. You also can change the specular to 1 and IOR to 1.45 . And play with the refraction depth in the settings of the material properties to come up with the results you want.


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Blender 3.1. use_gpu_subdivision, How can I turn that Option on with python code?
How can I turn that new 3.1 Blender Feature Use GPU Subdivision with Python code?
I tried with bpy.types.PreferencesSystem.use_gpu_subdivision = True but it doesn't work. Any ideas?

The answer is simple :D
bpy.context.preferences.system.use_gpu_subdivision = True

Enable GPU acceleration for evaluating the last subdivision surface modifiers in the stack

Link to the docs

Hope you don't mind, I added a little bit of info to your answer. Thanks for your contribution !


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How to give sapling tree gen more volume?
I found this foliage artwork on Art Station https://www.artstation.com/artwork/r9dBXL, and I am in the process of trying to replicated it. In his software description, he said he used Blender, and by looking at the branches it looks like he is using Sapling Tree Gen add-on.
Here is the reference vs my failed attempt.

My problem is the branches looks like kabobs with leaves on it, and the core of my tree is hollow. To fix it I've tried many settings in the add-on. For example, adding more leaves, less leaves, adding more branches, changing the rotation of the branches etc. None of it really helped me achieve the volume I was looking for.
Now you guys are probably going to point me to this guide https://www.youtube.com/watch?v=wPBX9kqcHzE, but with this technique I also had trouble achieve the reference look. In my experiments the leaf cluster I made looked like rounded spheres, which looks unnatural.
For example, my tree looked like this artwork I found.

Does anyone know what this person did to give their sapling tree gen so much volume?
If you look closely at the reference tree it looks natural. It just doesn't look like they used a sphere here and sticked leaf card normals to the surface.
Right now, my hunch is the ref tree was made using particle system to generate location of the leaves from the tree's center with some fall off curve. Or there is a setting in sapling tree gen that lets you add more branches to the center of the tree, thus when you add leaves it will look denser in the center creating the illusion of having more volume.
Honest, at this point I am just lost, so does anyone have any ideas of how to get the same look?

Somewhere in sapling there is an iteration option which will create smaller and smaller sub-branches.

Could also be that the leaf object is not a single leaf but a full cluster.


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Boolean after Bevel, using difference doesn't work correct
I'm using latest blender 2.82.7.
Steps:

Create box and bevel the edges on the top, to be like arc.
Shade smooth and auto smoothing.
I have other box and I try to boolean.

The object are like Union, instead of Difference.
During boolean:

After apply of boolean:

Thanks

Your smaller beveled object is not manifold. Select all vertices > Alt-M > 'By distance' to remove double vertices and zero-sized faces.

Ha, here is the funny part: I followed your steps and at the first try - it work. I didn't save and quit then open again and at the second time - did not work. Ah...

It will work.. check around the start of the bevel for double verts. Move them about a bit and right-click to drop them back where they came from.

Wow, you are right. I didn't know how to select All, ctrl+a doesn't work, but only A it seems is the key. So after select All and repeat steps - Hooray! Thank you very much for the encouragement!

A to select all, Alt-A or double-A to deselect all.


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Wheel Rotation Driver
Hi everyone I'm still a beginner at blender and I'm trying to make a simple wheel rotation using empty and drivers, the wheel rotates fine when I move the empty on local Y-axis but the problem is when I try to turn the empty on local Z-axis the wheel also rotates in place, this is not what I want and I don't know what's wrong, anybody has a solution? thank you very much

It looks like an issue with driver settings (global  to local convertion) or you need to create another driver for rotation.

So I need to create another driver to force the rotation?

This set-up is only good if you are going in a straight line. You have not said anything about parenting or driver settings. By looking at your gifs, I can assume you have the wheel parented to the Empty, and your driving the wheels 'X' rotation with the Emptys 'Y' location in 'Local' space, Am I correct so far ?? Even if you change the drivers space to 'World' or 'Transform' - you will still have a 'Coordinance' issue. So then you start thinking , I will use an armature bone(s) - well you will run into the same 'Coordinance' issue again. This issue has been highly debated over at BA for many years, we refer to it as 'the tank track issue', it is a shame that something so basic is so troublesome. So clockmender wrote an animation node to overcome this issue, but if A/N is not your thing, then this is my solution I use; I create 3 actions for the wheel, (1) START (2) TRAVEL (3) STOP -- You can combine these into one action, but I find this way more flexible. You assemble those actions in the NLA, then all you have to worry about is animating the steering. Hope this helps in some way.

Hey thank you for the answer! Yes your assumption is correct I parrented the wheel to arrow empty > then I parrented the arrow empty to cube empty. I actually didn't expect this to be a complicated issue . I have animation node but i havent try it yet. I'll try the NLA editor tommorow. Thank you again for the answer!

Please provide examples for your answer. As it is it is not helpful to the community

It would be great if you had a minimal toy example of the 3-state solution to show..

I currently use 2 transform constraints for wheel rotation. One mapping x location to my desired wheel rotation and one mapping y location to the same rotation.
Either that or I keyframe an empty to move along one axis then map that empty location to the wheel's rotation and its curve offset(when using follow path). Add an expression to the driver to convert distance into rotation using the diameter of your wheel.


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Importing XPS model
I'm curious how an imported XPS model armature seems to have IK constraint already, but it has no constraint at all. So how it is possible? can I also create a rig like that without constraint? It can be animated just fine

example1

example2

no constraint

Do you have Pose Mode -> Tool -> Pose Options -> Auto IK enabled?

Oh man! that's exactly what i'm looking for, Thank you!


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Scaling metarig model causes neck deformation
I am trying to scale my model in another file and when I do, the neck becomes skinny,tall and the shoulders are all weird when I scale the model. I've already tried clearing the transformations and applying transformations. Especially when it comes to scale, the whole mesh explodes when I apply it. This is very weird because it's all because of the metarig. if it was a normal armature, it wouldn't have an issue. FYI, the model I'm trying to scale is not a model I made, it's a model I downloaded of the internet. I'm trying to scale it alongside my other model. I've tried all the other ways I've found on this forum for similar issues but to no avail./
In some way the scaling is right BUT-- when I move it up, it still has that issue with the shoulders and neck when I try moving it up beside my other model. I can see the shoulders shrinking when I move it up.

The simpler solution is to use the root bone in pose mode to scale and move the whole rig + character system.
If you really need to have the new scale applied, the procedure is to delete the rig, scale the model and the Metarig together in obj mode, apply the scale to both model and Metarig, then regenerate the rig. All weights will remain preserved.


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Parent the model to the rigify error
When I parent my model to a Rigify rig, I get these deformations:

Here is a video of the steps taken: https://www.youtube.com/watch?v=ttt0-aabLQY

Hi, Pumpkin, if my edits don't reflect your question properly, please revise them.. give folks as much info as you can, in the post, to help them help you.

Before parenting models to a rig:

Apply both models' and rig's scale in object mode:
CtrlA > Apply Scale
Remove any pose from the rig by either:

entering pose mode and using ALTG, ALTR and ALTS.
Properties Editor > Armature tab > set it frome Pose to Rest Pose.

Maybe try applying all rotations, location to deltas, and scales


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Can installing the latest build of Blender work to replace a previous build?
I need to replace Blender 2.80, which I am unable to uninstall with Blender 2.82a.

To get a better reply I provide this info: Blender 2.80 does not have a way to uninstall it on my PC. There is no uninstaller, and it does not appear in the Installed Programs list of the Control Panel.

Related: How to Uninstall Blender Software

Blender Installer doesn't automatically remove older versions. It also useful to have one older version installed, just in case :).


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Large city file that needs to be made manifold but is too complex and will always make blender crash
I have a big and complex file, an stl that was imported from blenderOSM (openstreetmap) and it imports meshes found in google maps via an addon.
In my case I imported the Vatican and the whole idea is to get the file to a manifold, 3dprintable state. I need the file to keep most of the detail too.

The problem is that it has so many non manifold geometry that when trying to use the modifier Remesh it will most certainly crash. I have tried simplifying the mesh by merging vertices by distance, but this still doesn't take care of inner geometry in most of the buildings.

I have even tried using other software such as Maya and trying to remesh and retopo but it still will get my pc to crash.
There is an option in the blenderosm addon that lets you import the buildings from the OSM database, but these ones are nowhere nearly as detailed as the google map ones (photo 4). Google maps has even the trees, bridges, canals and even the cars included.

We can't really help with this since we have no access to your mesh. Also it's way to big and complex, I doubt it can be solved without manually going through every problematic non-manifold area. Why don't you do it by smaller chunks? I think that is the only alternative.

Hello @HarryMcKenzie thanks for the reply! I will try to upload the mesh. Indeed it is very complex but I have been able to remesh another file once, it was another city and while it took a lot of time it did work.

Quad Remesher is a really good remesher addon but its not free.


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How do i get chromic abberration on JUST shadows like in this reference image?

Link of the artwork: https://www.behance.net/gallery/123782593/Teddy-bear-Mini-Movie
To clarify I'm aware that there is lens distortion in the whole image but what I'm specifically asking is how did this artist manage to also get distortion on JUST the shadows (as marked by the arrows) without it affecting the objects around it?
I tried using a shadow catcher with an alpha over, so that I could just force it together in Photoshop, but I can only manage to get the render pass in only black and white.

Then I thought maybe I could do something with direct diffuse render pass, but I don't know how to composite the distorted shadows render pass into the final render.


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Importing PSA animation to my model only moves head but is still distorted
ive imported a PSA animation from UE viewer and the head only moves but is upside. I also tried this on other models and it completely distorts and stretches those models. It seems that it just ruins the model everytime i import the PSA animation. I reset the transformations always and i honestly have no idea how to solve this, i cant think of anything. I've used RIGIFY to rig my character model


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Mesh has zig zag cracks after automatic weights
I am trying to rig a video game character model that I did not make. It's a God of War Raganrok model and I had to rig it myself and after doing automatic weights... i pose it and there are very weird cracks when the model moves. It's very strange.

Probably go to edit mode, select all and Merge by distance .... I'm not sure, but it could destroy UV map.

You are certainly correct about that. I merged by distance it worked. I think the UV Map is okay...

OK ...Than great ◉‿◉ ... Good luck with your project.


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how can I rig a 2D face onto a 3D model
I'm trying to replicate the faces as seen in the Lego Movie, and somehow they get them to move. Someone recommended using the grease pencil tool, but I'm not sure how. These are like textures, but they rigged them inside the engine they were using. I would understand using black planes as eyes and eyebrows, but not if you want a 2D mouth that can open. I'm sorry if this question has been asked before, but I'm unable to find one like it
I understand this is a different engine, but is there a way to even do this in Blender?

https://www.youtube.com/watch?v=XN7lou-YAY0

I'm still unsure of how this is done. That was just an example.

I think your best option is shape keys and drivers. https://www.youtube.com/watch?v=vN6XCpDWDcg

uv warp modifier, https://www.youtube.com/watch?v=BopkonvbCEE

I'd find it a bit hard to animate using textures, even though I know it is sometimes done. For Project Gooseberry, I read in one of the weeklies that they were thinking about animating UVs using drivers on bones to achieve this effect for the caterpillar scene, but it didn't look all too intuitive.
My approach would be to use the traditional armature tools, combined with a shrinkwrap modifier workflow. It would be too long to explain everything, so examine the (simple) blend here:

The trick is to have the armature deform the face mesh before projecting it onto the head mesh using shrinkwrap. So all deformation happens in a flat plane, the result is wrapped onto the head with some offset. This is what it look like before projection:

And this is after:

I use the same technique for the eyes, however you can see the distorsion on the circular shapes a bit too much for my taste, so here deeper involvement would be needed. For the mouth it works a lot better:

I really quickly hacked this together to show the concept only, much more dedication needs to go into carefully weighting this, but alas, where you take this approach to is up to you.

Thank you, I will be trying this out in the next few days. I appreciate the created model for example too.

This is not the elegant answer offered by @aliasguru, rather a straightforward approach, posted for those  not overly familiar with Blender and wanting to get a face 'talking' using 2D photographed or sketched lips.
The cube shaped head was used purely out of convenience and for speed.  Planes can be easily wrapped around cylindrical surfaces such as Leggo heads.
Two planes were used here, one textured with a filled in oval shaped pic for the lips and mouth, another, not textured but subdivided to form teeth, gaps, and mouth cavity, each filled with their respective solid colour.
Pic 1 shows the 3D arrangement of these during construction and the bones used to deform their shape.

The bone structure has four bones on each side, their chain settings in the 'Inverse Kinematic' constraint set to 1-4 respectively and outwards from the center. The vertical or main armature is left at zero.
Both planes are parented to the main armature (vertical one)and set to "Automatic Weight".  The planes can also be scaled & transformed (moved about) independently of the armatures in order to enhance their ability to express emotion.
Once completed the planes are moved quite close together (the teeth in front) then the armature structure is moved inside the head so the planes will end up against the face.  The bones are parented to the head so the mouth is in effect, 'attached' to the head.

Teeth can be made to disappear alltogther by keyframing either an instant transform behind the lips, or adjusting their transparency.
The mouth gap faces in the Teeth assembly plus the lips plane can be distorted independently in the z axis to "open and shut" to emulate speech.
I see no reason why this arrangement couldn't be synchronized with a sound file although I have yet to explore this Blender feature and subsequently not carried out sound tests.

Two ways that I think you could accomplish this:

Animating the texture in after effects: Create some lips, eyes, and brow poses that you can animate between and cycle through them to the audio in something like after effects. Export the video to frames and use that as the texture.
I don't know if blender has this but I am pretty sure you can set driven keys in maya to animate textures, which would take out the step of animating the face in after effects.


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Is it possible to omit some objects in a scene from being affected by the environment texture lighting?
I have a scene setup with some objects which i want to be affected by the environment texture i have created and some which i dont (they are darker areas and are being lit up too much) - Is it possible to omit some objects in a scene from being affected by the environment texture lighting?

I guess you need to use the Compositor

There is no way to render it all at once in Cycles. You can use 2 different View Layers with collections as masks to render twice and composite them in the compositor.

great thats a good fix, thanks very much for that. shame theres no way to have more control over the lighting prior to render...


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Trouble with 'artifacts' appearing on curved surfaces wiiith shiny material
could anyone help me with troubleshooting what these 'artefacts' are which are appearing please? It becomes more apparent when the roughness is turned down. I've tried rebuilding the mesh in meshmixer but get the same problem. Thanks.

hello, could you please share just the part you're showing? https://blend-exchange.giantcowfilms.com/

check the normals.


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including decals in weight painting for rigged models
I have created details on a character models clothing using the method described

here

which basically copies the underlying mesh and projects the detail onto it. this works well because i can have a high resolution detail (such as a logo on a shirt) without having to make the whole shirt match that resolution. this technique works fine for still models but as soon as i try to rig the model using auto weight painting it runs into problems. it seems that the decals, despite being exact replicas of the mesh underneath them, are not included in the weight painting and so react unpredictably(i have tried joining and boolean union on  the mesh) . is there any way to get past this without having to bake on these textures which would result in the need for a very large resolution texture?
many thanks.

I think that you should be able to make use of 'empty weights' and mesh data transfer to copy the weights from your weight painted body to the separate clothes.
I came across this useful answer that should hopefully be of use to you : https://stackoverflow.com/questions/34719718/transferring-rig-weights-from-one-mesh-to-another-in-blender-2-76/34760742#34760742


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How to apply the texture on the model
The sleeves have been correctly unwrapped, but why don't I see the texture applied?

It seems like you have only opened the image in image editor but you haven't given your material the image texture.

You can give your material image texture by clicking the yellow dot next to Base color and by choosing Image Texture.

Next press Open and find your image.

That was so easy, thanks.


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Extrude without creating new faces
Hi, I am new to Blender
I have extruded these faces inward (arrow 1), but I had to come back to adjust it (arrow 2). When I do this I create new faces (with edge and vertices) that create me problem later on. Is there a way to do extrude adjustments without this happening?

2.90 should be addressing this (https://wiki.blender.org/wiki/Reference/Release_Notes/2.90/Modeling).

related: https://blender.stackexchange.com/questions/30874/push-faces-like-sketchup

From the point where each vertical edge was at Arrow 1, in edit mode you can shift-select each of those inset vertical edges, and then hit s to scale each edge and push them inwards.  That will move just those edges and their vertices all inwards (or outwards) symmetrically.
If you're already at Arrow 2 and can't go back, from edit mode you can select each horizontal edge at Arrow 1, hit "x" to bring up the delete sub-menu, and select Dissolve Edges to eliminate them.  You can then scale the vertical edges at Arrow 2 using the process above to move them without creating any new edges.
Does this accomplish what you were trying to do?

I have tried option 2 and it fixed my problems, however option 1 is no substitute for actual extruding.
What matter is that I fixed my problem, thanks :)

Great - please consider marking this issue accepted.


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How to make non perpendicular loop cuts
Usually a cut loop goes perpendicular from one side to the opposite and all around the adjacent faces of the shape. However I want to cut slices off all corners of my shape, from side to side and all around but with a non-perpendicular cut line (as shown in the picture). Is there a quick way to do this for all four corners?
#

Create loopcuts (CTRL+R) along the vertical faces.

Select all the horizontal edges.

Use: Edge>>Subdivide.

Set the number of the cuts at the bottom-left corner.

Select the loopcuts, what you made in the 1. step.

Use Mesh>>Delete>>Dissolve Edges

very nice, wouldn't have thought of this :)

And it's pretty easy to turn this into an all-quads mesh if so desired. Select a set of the outer three edges of varied length, then Shift G to Select Similar > Length. Subdivide. Then use Knife Tool with Cut Through enabled from Top View twice in an X pattern.

@Mentalist The all-quads mesh is always a good idea.

It is not something that it seems you can do directly. But here is a potential workaround:

use the knife tool (K then C) to cut through the whole mesh and create a diamond from the centers of the edges (by pressing SHIFT while cutting) and triangles in the corners:

now you have the proper geometry to add loops in the corners (CTRL+R):

After that if needed you can remove the excess geometry by selecting edges and pressing CTRL+X to dissolve.


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the eye is rotate when i move the character
when I move the character from this root bone

 the eye turn from this

 into this weird looking

 its rotate to much and I don't know what can I do
 and when I try to move or rotate any bone it is
 rotate so please help me

there must be a bad parentage, make sure the eyes are correctly parented, probably to the head bone

when I parented it to the head bone is do out the body and do not came back and whan I try different bones steel go out the body but from another direction

and steell rotate

Please share your file or at least a part: https://blend-exchange.giantcowfilms.com/

sorry is a special prodect can you go  with discord please

this is my user name fares#5259

or you can choose any platform if you like cause a need you help

and am so sorry if I bothed you

correction Bothered you

just share the armature + eye mesh, delete the rest of the mesh  ;)


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Texture painting turns pink
When I try to go and texture paint, my object turns pink and I do not have access to paint brushes. I smart unwrapped the object already. This is in blender render. I also get the message Missing data.

The question isn't the same as the suggested duplicate.

The question indeed isn't a duplicate of linked one and can be reopened (and to be closed as a duplicate of another one). Related - http://blender.stackexchange.com/questions/31933/texture-painting-mode-missing-data-warning

You missed this little step here ...

For the type, add image texture.
Point the target to the texture named "untitled" you have created in your image editor.
Change the Mapping Coord from "Generated" to "UV" - Paul Gonet

Additional Notes
 When you are done painting your texture go to the UV/Image editor and press F3 to save the image. Otherwise all of your work will be lost. Saving the blend file will not save the image with it. Please read this link: Why did the texture I painted in texture paint mode disappear?

Image painting will display in render view mode in Cycles setup, but
  to make  sure the image renders, you need to save the image to
  directory and save the changes you make. Many users forget to do this,
  and assume that saving the file will save the state of the image
  painting, and this is false. In the Image Editor, you can choose 'save
  image' or 'save image as' and iterate changes to new images if you
  want. You can also indicate 'pack into file' from there, as well as
  'pack external data' from the File header. - Craig D Jones

Also remember to change the coordinates from 'Generated' to 'UV'.

Thanks, this really helped. When I have drawn on the cube, will it appear during render?

Image painting will display in render view mode in Cycles setup, but to make sure the image renders, you need to save the image to directory and save the changes you make. Many users forget to do this, and assume that saving the file will save the state of the image painting, and this is false. In the Image Editor, you can choose 'save image' or 'save image as' and iterate changes to new images if you want. You can also indicate 'pack into file' from there, as well as 'pack external data' from the File header.


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Can framerate be randomized?
Is it possible to randomize the framerate within one video?
For example, if I have a video shot at 25 fps, is there a way to make this video randomly play between 10 and 40 fps at different times during the video?  The goal would be to produce a 'glitchy' look when the video is viewed.
I only need to know if this is possible; I don't need to know many details.  Thanks in advance for your input.

Why would you want to randomize the framerate and what is the effect you are trying to achieve ... posting a video of a similar effect may help others understand the question better. I say this because seldom would anyone do this. If this is an intended effect ... well I can only think of one good way of doing it ...

This will require a huge amount of unnecessary computation, so I'm not writing it as an answer, but you could render your "glitchy" scene at highest possible fps, remove images randomly, rename them to be sequential and then convert to video.

Your final video will have a constant frame rate, but you can cut and mix pieces of video into your final output that play at altered speeds from their original source.
You most likely want to use the Effect Strip->Speed Control. There is also a strobe property for a video strip. Don't be afraid to keyframe properties to get varying effects during the length of your video.


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normal map problem for mirrored dupli groups in cycles
A building front is created by placing group instances as dupli groups.
The group is a wall element with an asymmetric window which is placed in the scene
alternately mirrored and not mirrored.
When texturing the elements with a normal map texture
I noticed a different result for the mirrored group instances.

I guess the problem is caused by the mirrored mesh normals of the mirrored group instances
because without normal maps the result is the same for both orientations.
Is there a solution to solve this texture problem without dropping the dupli groups?
I use the dupli groups as a fast way to generate design alternatives.


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Copy UV scale within one object
This problem has been addressed many times before for copying UV's from one object to another object. But I need to copy UV map scale from one face group to another within the same object. In the example I've a brick texture that I've sized 15 times on X and Y. Now when I apply the same material to the chimney the texture is much smaller because the UV map is smaller. I can scale it by hand in the UV editor, but it will be difficult to hit the same scale factor and it just seems so random to do. Is it possible to just copy the UV scale from the walls? I know it's possible in 3DS Max..

How we usually go about matching the uv is to scale all the uv which are suppose to have the same materials together after matching the scale with Ctrl+A (Match island scale operation.) If this is impossible in a particular workflow. Then try the following:
We usually end up using a checker map pattern to eyeball the sizes of the checker, to approximate the scale of every surface before applying the actual material.

Create a color checker image go for 2048x2048
Apply the checker to all the surface of the model.
Enter Edit Mode and duplicate the faces in question and move it near the faces that has the scale you want to match. (Step for easier eyeball comparison)
Select the duplicated face in the UV Editor and start scaling.
Match the sizes in the checker pattern, and take note of the scaling factor
on the bottom left hand of the uv scale before hitting LMB .
Delete the duplicated face.
Enter the scale value from step 5. to the faces you want to affect.

If these answers are not satisfactory or understood, will be glad to post some images to help explain the workflow.

It's my first model in Blender that I'm making after a Youtube tutorial and the author pointed out that it's important to mark seams all the time during the build up process. I did so but when it came to texturing it showed up in the UV editor, that my maps for the building are only partly okay. Only one wall had parallel map edges in the UV editor, the others were somehow bended and upside down etc. Thats why I did a project from view map on each wall individually and a cube projection on the chimney. This is how I ended up in this situation. What should I have done differently?

Use the method above when you can't get a fluid workflow to keep the scale of all the uv. Very often and in fact most of the time, complex models will end up with various method of unwrapping and have problems with scale. The truth is much later down the road it's a good thing, cause not all texture will appear right with one scale, hence the ability to scale them individually helps. As with seams and marking them. Try to learn how to unwrap simple objects and grasp it's concept. Just like all other things in life , the more you practise the better you get.

I hate eyeballing stuff.
My situation
I have attached a small face to an already textured object, applied the same material to the new face, ended up with completely misaligned UV-mappings:

The UV-editor:

In my situation modifying the UV-mapping of the original face (and the rest of the object) is not an option.
How-to
I can see that I need to rotate the UV-mapping of the new face by 90°. (In the very first image you can see how the texture of the new face is rotated by 90°.)
And I know the vertical scale can be matched by simply aligning the two vertical edges in the UV-editor.
Let's do that:

NOTE: Because the new face is touching the old one with its right side that's also the side its texture needs to be aligned to.
(By shifting the left edge of the UV-mapping in the UV-Editor along the horizontal axis you will be able to tell which edge is the texture aligned to. If it is not the Right one, rotate its mapping by 180°.)
The rest of the challenge is to "copy" the horizontal scale of the old face to the new one.
To achieve that you need to do following:

Calculate the ratio of widths of both faces: use Measure on both of them -> new_face_width / old_face_width;
apply the width-ratio to the width of the UV-mapping of the new face.

In my case the ratio ended up being 0.04761806754935521746299985989727
To apply the width-ratio you calculated:

Align (only!) the width of the new face's UV-mapping with the width of old face's UV-mapping (use snapping "Snap to vertices" to maintain accuracy):

Apply the width-ratio to the new face's UV-mapping by scaling it along the horizontal axis: by first dragging the red axis of the scaling gizmo (doesn't matter by how much) and then copying the previously calculated number into the Resize dialog. You will end with something like this:

Finalize
Now just move the new face's UV-mapping back to its place (use "Snapping to vertices" again):

The result


text:
What could have caused these black outlines
I tried to render an animation that I've made, by rendering each frame as a picture first, and I'm getting these black outlines. I have rendered this animation before and the produce didn't have any such outline, but I have tweaked and changed some things around since... I don't necessarily hate the lines, but it would be nice to know what might have caused them. Could it be the "Freestyle" setting, by any chance?
Thanks for your help!

It does indeed look like Freestyle. If you turn it off (Properties Panel->Render tab->Freestyle setting) what happens?

yes, it did turn out to be Freestyle, thanks