Maniphest T53854

Overlapping volumes render incorrectly with branched path tracing
Closed, Resolved
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Assigned To
None
Authored By
Stefan Werner (swerner)
Jan 22 2018, 10:32 AM
Tags
  • BF Blender
  • Cycles
Subscribers
Brecht Van Lommel (brecht)
Stefan Werner (swerner)
Cycles

Description

This bug is verified on macOS and Linux in commit c723e91ee155612b68950ca2a44b49bdd3c72838

Git bisect points to commit cd023b6cecb7b8c74de1d16510ad09668b86001f as the one introducing this bug. Said commit was part of D2766.

overlapping_volumes.blend485 KBDownload

Revisions and Commits

rC Cycles
rC9302f496e23b Fix T53854: branched path tracing correlation bug with transparency in split…
rCd5d609f292b0 Fix T53854: branched path tracing correlation bug with transparency.
rB Blender
D3015rB2838cf0dfe6c Fix T53854: branched path tracing correlation bug with transparency in split…
rB8a2d09eb9f5a Fix T53854: branched path tracing correlation bug with transparency.

Related Objects

Mentioned In
D12610: Fixes T91632 by stopping the sample correlation between dimensions which was causing rendering artifacts on simple scenes.
rB93901e7f0a05: Tests: speed up render tests by running multiple in the same process
T54317: Overlapping volumes render incorrectly in path tracing
rBL61986: Cycles tests: update for T53854, branched path tracing correlation bug.
Mentioned Here
rBcd023b6cecb7: Cycles: remove min bounces, modify RR to terminate less.
rBd750d182e58f: Code cleanup: remove hack to avoid seeing transparent objects in noise.
rBc723e91ee155: WM: add mouse-move after smooth-view
D2766: Cycles: remove min bounces, modify RR to terminate later.

Event Timeline

Stefan Werner (swerner) lowered the priority of this task from 90 to 50.Jan 22 2018, 10:32 AM
Stefan Werner (swerner) created this task.
Stefan Werner (swerner) added a project: Cycles.
Stefan Werner (swerner) added a subscriber: Cycles.
Stefan Werner (swerner) added a comment.Jan 22 2018, 1:20 PM

It looks like this happens with plain transparency too - branched path tracing and plain path tracing give different results. See the attached scene.

overlapping_transparencies.blend506 KBDownload

Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).Jan 22 2018, 2:03 PM

rBcd023b6cec just changed the noise, the issue was in rBd750d18.

Brecht Van Lommel (brecht) changed the task status from Unknown Status to Resolved by committing rB8a2d09eb9f5a: Fix T53854: branched path tracing correlation bug with transparency..Jan 22 2018, 2:03 PM
Brecht Van Lommel (brecht) added a commit: rB8a2d09eb9f5a: Fix T53854: branched path tracing correlation bug with transparency..
Brecht Van Lommel (brecht) mentioned this in rBL61986: Cycles tests: update for T53854, branched path tracing correlation bug..Jan 22 2018, 2:10 PM
Stefan Werner (swerner) added a comment.Jan 22 2018, 2:49 PM

Thanks, that was quick.
You're right, D2766 only made the issue more visible - it was present in earlier revisions as well when the min transparency parameter was set low enough.

Brecht Van Lommel (brecht) added a commit: rB2838cf0dfe6c: Fix T53854: branched path tracing correlation bug with transparency in split….Jan 23 2018, 11:28 AM
Sergey Sharybin (sergey) added a commit: rCd5d609f292b0: Fix T53854: branched path tracing correlation bug with transparency..Feb 13 2018, 3:25 PM
Sergey Sharybin (sergey) added a commit: rC9302f496e23b: Fix T53854: branched path tracing correlation bug with transparency in split….
Stefan Werner (swerner) mentioned this in T54317: Overlapping volumes render incorrectly in path tracing.Mar 16 2018, 2:04 PM
Ray Molenkamp (LazyDodo) mentioned this in rB93901e7f0a05: Tests: speed up render tests by running multiple in the same process.May 14 2019, 7:17 PM
William Leeson (leesonw) mentioned this in D12610: Fixes T91632 by stopping the sample correlation between dimensions which was causing rendering artifacts on simple scenes..Sep 24 2021, 9:34 AM