37 votes
Accepted

Why does my object not show up?

This is the overview. I am breaking up the parts into individual answers that we can link to from other questions. This is a community wiki, so feel free to add ones that need to be addressed ...
21 votes
Accepted

Can someone explain the layer system?

Layers Layers are a way of splitting up and organizing the objects in your scene. In the 3D viewport. You can select the currently visible layers in the footer of the 3D view or under properties ...
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  • 24.4k
15 votes
Accepted

Where do the white lines come from in my composite?

Those two images you're trying to composite together have "correlated" alphas. The Alpha over operation isn't the appropriate operation for this situation. The solution is simple: you just have to ...
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  • 2,150
13 votes
Accepted

How can I render all render passes to files in Cycles?

Render OpenExr Multilayer for Blender, Nuke and Natron. Go to the Scene Tab, enable all passes which key for compositing and set the Output Format in the Render Tab to ...
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  • 14.6k
11 votes

Is there a way to have Cycles skip rendering alpha?

There is nothing specifically designed into Blender to tell it to ignore the transparent areas currently. That being said, there are some things we can do to help speed up the render somewhat. ...
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11 votes
Accepted

Cycles rendering objects all black

I think what happened here was just a misclick in your render layer settings. It looks like you accidentally added a layer as a mask layer. What is a mask layer A mask layer is a layer that is used ...
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  • 5,512
10 votes

How can I render all render passes to files in Cycles?

Another alternative is to render out to separate image sequences. This is handy if you want to output to different render formats for each Render Pass. As well it gives you the flexibility to only re-...
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10 votes

How to denoise animations using Blender's Temporal Denoiser?

How to use the Temporal Denoiser Step 01: Pack Denoising Data Enable denoising data in View Layer > Passes > Denoising Data Set file format to OpenEXR Multilayer (so Blender packs the ...
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8 votes
Accepted

Compositor result won't show

To enable compositing go to Post processing in the Render tab of the Properties Panel and: check the Compositing option uncheck the Sequencer option this will process the render result through ...
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  • 18.9k
8 votes

Blender 2.8 View Layers - "Exclude" feature

Old "Render Layers" are now here, in the top right corner: In the context menu (RMB) in outliner you can set to any collection to be Excluded, masked (now holdout) or hided (now Indirect Only). ...
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  • 25.6k
7 votes

Is there a way to have Cycles skip rendering alpha?

Full disclosure, the add-on I'm about to recommend is a paid for add-on created by me, but I think it does what you need as it was built partially for the very task of skipping transparent parts of an ...
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  • 28.1k
7 votes
Accepted

Repurposing vector (speed) render layer for optical flow

Found the solution. The trick is to enable the desired render layer (ie "vector") and then save the render output as OpenEXR file. That format will save all the desired render layers (in this case, ...
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  • 193
7 votes
Accepted

Transparent render layers

It could be that you are not actually providing the compositor with any transparency. The alpha output socket from the scene node will just be a solid white unless you check the following properties: ...
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  • 8,794
7 votes
Accepted

How to have Denoiser ignore certain objects?

The Denoiser in Blender version 2.79 can be activated per Render Layer, and as such you can mix denoised and noisy footage as you like. If you ever wondered why the Blender Devs have put that Denoiser ...
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  • 10.5k
7 votes
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How do I rearrange the list of render layers?

Render layer order doesn't actually effect the render (aside from maybe changing the order in which the layers are rendered). However, for organisational purposes it can be nice to reorder them. For ...
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  • 28.1k
7 votes
Accepted

Scene complexity and VRAM

I bet those 4x8GB gpus are much faster than single 32GB card. Here are some options: Get the faster setup and a renderer that can do out-of-core rendering like Octane or Redshift. This allows your ...
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7 votes
Accepted

How to create wireframe fade off effect like this?

Various aspects of a Freestyle Line Style can be given modifiers, including the Alpha of the stroke. The modifiers available to Alpha include Distance From Object. (In this example, the blue empty): ...
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  • 56.2k
6 votes
Accepted

How do I render specific render layers using python?

Here's a little script, that iterates over all render layers and checks for some condition (e.g. does the layername start with 's'?). Then it disables all render layers and enables one that fulfills ...
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  • 27.2k
6 votes
Accepted

Z-buffer output from blender as file

The values of the Z Buffer are in float values, and then they get clipped to <0,1> (<0,255>) range in your file format. Either save the images in some hdr format (.exr for example) that will ...
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6 votes
Accepted

How to make an object transparent to the freestyle pass?

The source of the problem is that Freestyle view map has (can see) the smoke domain geometry. This is a typical problem. Transparent mesh like glasses can be solved with the same method. Put torus, ...
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  • 426
6 votes
Accepted

How to move objects to new Render Layer?

The way this works is indeed quite confusing. TL;DR: M moves objects between layers, which are independent of the many layer visibility settings. Long answer: There are 20 layers and several ...
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  • 152k
6 votes
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Is it possible to give each render layer specific render settings?

You can't switch between CPU and GPU if the render layers are in the same scene, but you can have multiple scenes that each use a different rendering device (CPU/GPU). You can then work in the ...
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  • 28.1k
6 votes

Why does my object not show up?

2. Render layer not showing in the compositor Documentation: https://www.blender.org/manual/render/post_process/layers.html#render-layers There are actually a few different ways to run into this kind ...
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  • 8,039
6 votes

How to re-render specific view layers?

How about one at a time using "Render Single Layer" check box? Or simply deselect the "Use for Rendering" from the layers you don't want to re-render.
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  • 3,921
6 votes
Accepted

How to save render layers for later use

Simply set the output format to OpenEXR MultiLayer and save the render, it will store all render passes. Create another project for the compositing where you load the image(s) through an Image node. ...
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  • 23.8k
5 votes

Cycles alpha mask hole

Those are correlated alphas. That basically means that you're not putting layer B over Layer A, but putting layer B in a hole poked in Layer A. The regular alpha over operation, however, will work ...
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  • 2,150

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