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CyclesProject
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Description

What is Cycles?
Cycles is a ray tracing renderer focused on interactivity and ease of use, while still supporting many production features.

Contacts

Documentation
Manuals for both Artists and Developers are available.

Development
Cycles is officially under the Blender Foundation umbrella, and so is developed on developer.blender.org. Source code is available either as standalone repository or as bundled into Blender sources.

To clone Cycles together with blender please consult BF Blender project.

To clone Cycles source from stadalone repository as read-only use:

git clone git://git.blender.org/cycles.git

To clone as read-write (needs ssh key):

git clone git@git.blender.org:cycles.git

Browse code
Online browse of sources is available for:

Module Owners: @Brecht Van Lommel (brecht) @Sergey Sharybin (sergey)
Developer Members: @Lukas Stockner (lukasstockner97) @Stefan Werner (swerner) @Mai Lavelle (maiself)

Recent Activity

Today

michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

It can also be used to get rid of shading artefacts on smooth surfaces:

Sun, Oct 20, 1:25 AM · Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

Also works with a bump texture:

Sun, Oct 20, 12:01 AM · Cycles, BF Blender

Yesterday

michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

Slightly better version:

Sat, Oct 19, 11:47 PM · Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

This seems to fix it. Left is a bump map, middle is a normal map, right is a normal texture run through an alternative node setup instead of the normal map node.

Sat, Oct 19, 10:54 PM · Cycles, BF Blender
Brecht Van Lommel (brecht) added a comment to T68920: Reduce shadow terminator artifacts.

No, we judge the priority, it is not determined by voting.

Sat, Oct 19, 8:36 PM · Cycles, BF Blender
Edgard Perez-Palma Vasquez (edg422) added a comment to T67718: Point density texture crashes.

Can confirm this on 2.81 hash: 970d7ed860f1

Sat, Oct 19, 8:07 PM · Nodes, Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

Is there any way to vote to get this escalated to high priority? I literally can't use cycles at all in scenes with curved surfaces that have bump/normal maps......which is most scenes.

Sat, Oct 19, 2:30 PM · Cycles, BF Blender

Fri, Oct 18

michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.
Fri, Oct 18, 7:55 PM · Cycles, BF Blender
Laurent Noel (c2ba) added a comment to T68920: Reduce shadow terminator artifacts.

It seems strongly influenced by the normal adjustment that was introduced in: https://developer.blender.org/D2574
For example by removing the line https://developer.blender.org/differential/changeset/?ref=147520 I get the following image:


For comparison, I have this without remove the line:

Fri, Oct 18, 3:55 PM · Cycles, BF Blender
Ron Richter (empai) added a comment to T55011: Incorrect wave texture visualization.

I can reproduce this behavior with Blender 2.80.75.

Fri, Oct 18, 10:14 AM · Cycles, BF Blender
Tautvydas Andrikys (esminis) added projects to T70915: Diffuse materials glow in corners or small gaps when using Principled Shader in Cycles: Render & Cycles, Cycles.
Fri, Oct 18, 9:30 AM · Cycles, Render & Cycles, BF Blender
Laurent Noel (c2ba) added a comment to T68920: Reduce shadow terminator artifacts.

Tried with Luxrender, it does not have the problem:

  • Lux:

  • Cycles:

Fri, Oct 18, 2:58 AM · Cycles, BF Blender
Laurent Noel (c2ba) added a comment to T68920: Reduce shadow terminator artifacts.

The test you suggested of adding extra subdivisions in edit mode should result in the shading artefacts because there's more geometry between the original edges. The same way you would intentionally add a hard edge by putting two edges close together.

Fri, Oct 18, 2:24 AM · Cycles, BF Blender

Thu, Oct 17

michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

Here's a perfectly cylindrical mesh with perfectly cylindrical normals:

Thu, Oct 17, 8:20 PM · Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

I've tried the same mesh in redshift and also in mantra. The shading issue is not there in either. See this bug report where I posted the comparison.

Thu, Oct 17, 7:50 PM · Cycles, BF Blender
Laurent Noel (c2ba) added a comment to T68920: Reduce shadow terminator artifacts.

I'm not really sure but I think it might be related to the linear interpolation of the vertex normals on the face, that does not match the true normals a circle would have (correct me if I'm wrong). So each face get a set of interpolated normals that is slightly wrong, and since the interpolated normal is used to build the shading normal with the tangent normal map, correlation artifacts appear.
Try the following: build a cylinder in blender, remove the top and bottom faces, then in edit mode select all faces and subdivide them multiple time. Put your cylinder in smooth shading and you will see the the individual original low res faces appear, even with opengl rendering.
I guess this is because the new vertices created with subdivision have a normal computed from linear interpolation, but I'm not familiar with subdivision algorithms in general and the one used by blender in edit mode so I can only guess. Try to display the normals on edit mode with the overlay, you will see that the normals of the newly created vertices do not create a perfect circular pattern.

Thu, Oct 17, 7:19 PM · Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

On the video above you can see that the shading issue is apparent even on the far right polygons where the light ray isn't passing through other faces and then hitting the back side of neighbouring faces.

Thu, Oct 17, 5:36 PM · Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

Thu, Oct 17, 4:56 PM · Cycles, BF Blender
Laurent Noel (c2ba) updated subscribers of T68920: Reduce shadow terminator artifacts.

Yeah the problem of shadow terminator for normal maps seems to be fixed thanks to https://developer.blender.org/D5399

Thu, Oct 17, 3:10 PM · Cycles, BF Blender
Sergey Sharybin (sergey) added a comment to D6075: Cycles: Improved equiangular sampling..

The idea sounds great!

Thu, Oct 17, 2:28 PM · Cycles
Stefan Werner (swerner) added a comment to T68920: Reduce shadow terminator artifacts.

Read the SIGGRAPH paper more closely - it applies to problems introduced by bump/normal mapped surfaces only. It is implemented and working.

Thu, Oct 17, 10:18 AM · Cycles, BF Blender

Wed, Oct 16

Jeroen Bakker (jbakker) added inline comments to D6075: Cycles: Improved equiangular sampling..
Wed, Oct 16, 9:48 PM · Cycles
Stefan Werner (swerner) updated the diff for D6075: Cycles: Improved equiangular sampling..

Commenting.

Wed, Oct 16, 8:29 PM · Cycles
Stefan Werner (swerner) updated the diff for D6075: Cycles: Improved equiangular sampling..

Code deduplication.

Wed, Oct 16, 8:27 PM · Cycles
Dalai Felinto (dfelinto) updated the task description for T66305: Render & Cycles Module.
Wed, Oct 16, 4:33 PM · Render & Cycles, Cycles, Rendering, BF Blender
Dalai Felinto (dfelinto) added a reviewer for D6075: Cycles: Improved equiangular sampling.: Sergey Sharybin (sergey).
Wed, Oct 16, 4:15 PM · Cycles
Charlie Jolly (charlie) updated the summary of D5957: Maths Node: Additional functions.
Wed, Oct 16, 2:48 PM · Cycles, Eevee
Stefan Werner (swerner) added a project to D6075: Cycles: Improved equiangular sampling.: Cycles.
Wed, Oct 16, 12:46 PM · Cycles
Stefan Werner (swerner) closed D5953: Cycles: Allow PTX targets for CUDA kernel build..
Wed, Oct 16, 10:30 AM · Cycles
Stefan Werner (swerner) updated the diff for D5953: Cycles: Allow PTX targets for CUDA kernel build..
  • Merge branch 'master' into cuda_ptx
Wed, Oct 16, 10:26 AM · Cycles
Stefan Werner (swerner) added a comment to D5953: Cycles: Allow PTX targets for CUDA kernel build..

I clearly don't know how to use phabricator.

Wed, Oct 16, 10:25 AM · Cycles
Stefan Werner (swerner) updated the diff for D5953: Cycles: Allow PTX targets for CUDA kernel build..
  • Cleanup: Fix naming of a functio - Cycles: Added "compute_xx" as architecture options to CUDA kernels.
Wed, Oct 16, 10:24 AM · Cycles
Charlie Jolly (charlie) updated the diff for D5957: Maths Node: Additional functions.

Add smoothmin and smoothmax functions (slower but very nice!).
Rename Almost to Compare, makes more sense and is used elsewhere in Blender.
Tidy math menu with headings.

Wed, Oct 16, 2:14 AM · Cycles, Eevee
Charlie Jolly (charlie) updated the summary of D5957: Maths Node: Additional functions.
Wed, Oct 16, 12:45 AM · Cycles, Eevee

Tue, Oct 15

Charlie Jolly (charlie) updated the diff for D5957: Maths Node: Additional functions.

Rename wrap to pingpong.

Tue, Oct 15, 7:31 PM · Cycles, Eevee
Charlie Jolly (charlie) updated the diff for D5957: Maths Node: Additional functions.

Add wrap, almost and madd

Tue, Oct 15, 6:51 PM · Cycles, Eevee
Zijun Zhou (Eary) updated the task description for T70800: Issue with toggling fullscreen in camera view in cycles.
Tue, Oct 15, 3:33 PM · GPU / Viewport, Cycles, BF Blender
Dalai Felinto (dfelinto) closed T70838: [Segfault<>BKE_object_is_visible_in_viewport] when rendering the default cube in cycles, despite viewport rendering works fine. as Resolved by committing rB7df7a8f3f1bb: Fix T70838: crash on cycles render after recent fix.
Tue, Oct 15, 3:31 PM · Cycles, BF Blender
Dalai Felinto (dfelinto) claimed T70838: [Segfault<>BKE_object_is_visible_in_viewport] when rendering the default cube in cycles, despite viewport rendering works fine..

Fixing it at the moment.

Tue, Oct 15, 3:14 PM · Cycles, BF Blender
Clément Foucault (fclem) closed T70772: Bump node ignoring smooth shading as Invalid.

It is matching Cycles. Which does respect the shading normals. The facet effect is caused by the extreme case of a normal being distorted too much.

Tue, Oct 15, 2:49 PM · Cycles, Eevee, BF Blender
Patrick Mours (pmoursnv) added a comment to T70838: [Segfault<>BKE_object_is_visible_in_viewport] when rendering the default cube in cycles, despite viewport rendering works fine..

Can confirm too. Happens because the old code in visible_in_viewport_get_func checked whether b_v3d is NULL before accessing it, but the new code doesn't (and the viewport can be NULL).

Tue, Oct 15, 2:28 PM · Cycles, BF Blender
Philipp Oeser (lichtwerk) renamed T70838: [Segfault<>BKE_object_is_visible_in_viewport] when rendering the default cube in cycles, despite viewport rendering works fine. from [Segfoult<>BKE_object_is_visible_in_viewport] when rendering the default cube in cycles, despite viewport rendering works fine. to [Segfault<>BKE_object_is_visible_in_viewport] when rendering the default cube in cycles, despite viewport rendering works fine..
Tue, Oct 15, 2:24 PM · Cycles, BF Blender
Philipp Oeser (lichtwerk) raised the priority of T70838: [Segfault<>BKE_object_is_visible_in_viewport] when rendering the default cube in cycles, despite viewport rendering works fine. from Needs Triage by Developer to Unbreak Now!.

Can confirm, assume rB280d6b03a7a9 is the culprit? (but will check on this...)

Tue, Oct 15, 2:24 PM · Cycles, BF Blender
Campbell Barton (campbellbarton) added a comment to T70800: Issue with toggling fullscreen in camera view in cycles.

Unable to redo this in 23b3b5bc76d0b250b1547bbb3fa991081fd6fe0f.

Tue, Oct 15, 9:59 AM · GPU / Viewport, Cycles, BF Blender
Jacques Lucke (JacquesLucke) added a comment to T70800: Issue with toggling fullscreen in camera view in cycles.

Maybe you could provide precise steps in text form? That is easier to follow than a video sometimes.

Tue, Oct 15, 8:14 AM · GPU / Viewport, Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

This seems to be the most used solution I can find:

Tue, Oct 15, 4:33 AM · Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

@Laurent Noel (c2ba), I think someone should try an automatic solution before we add manual settings.
The issue happens when a reflection ray goes into the mesh, and then wrong shadow comes from when it exits. So if we ignore that exit, it may solve the most common type of problem. It's even possible to experiment with this using just a shader setup with a transparent BSDF on the backside, to see how well it works. Either way, any solution will need changes to the BSDF evaluation first.

Tue, Oct 15, 3:55 AM · Cycles, BF Blender
michael campbell (3di) added a comment to T68920: Reduce shadow terminator artifacts.

same problem with volumes too? identical model left and right

Tue, Oct 15, 3:21 AM · Cycles, BF Blender
Zijun Zhou (Eary) added a comment to T70800: Issue with toggling fullscreen in camera view in cycles.

Really?But I can reproduce it here every single time!

Tue, Oct 15, 1:12 AM · GPU / Viewport, Cycles, BF Blender
Evan Davies (EDcase) added a comment to T66529: [Cycles] Motion Blur of fast rotating objects "randomly" glitches.

Test scene still does not work properly with 2.81 build 14 Oct 2019

Tue, Oct 15, 12:26 AM · Cycles, BF Blender