Maniphest T48571

Cycles/GPU - A lot of fireflies is this scene (mostly from Buildbot)
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Assigned To
Sergey Sharybin (sergey)
Authored By
YAFU (YAFU)
Jun 2 2016, 2:30 PM
Tags
  • BF Blender
Subscribers
YAFU (YAFU)

Description

System Information
Kubuntu Linux 14.04 64bits - GTX 960, 352.79 driver

Blender Version
Broken: mostly from Buildbot Hash 24712b1

Also a little less on 2.77a

Short description of error
I had a scene used to test slow materials on GPU:

slow_cycles_gpu_with_sss.blend834 KBDownload

and I have found that in Blender from Buildbot generates a lot of fireflies in the material including Subsurface Scattering. This does not happen with CPU.
Anyway, I found that this problem also occurs in Blender 2.77a, but this is much less noticeable.

Another thing to note, if I do not use SSS as in this scene:

slow_cycles_gpu.blend801 KBDownload

There is also some little more fireflies from Buildbot compared to Blender 2.77a, but also fireflies appear on CPU.

Exact steps for others to reproduce the error
Open the scenes that I have shared and render in GPU / CPU in the corresponding versions of Blender

Revisions and Commits

rC Cycles
rCa44c454e1d16 Fix T48571: Cycles/GPU - A lot of fireflies on SSS+Volume
rB Blender
rB14f9a5aa1de8 Fix T48571: Cycles/GPU - A lot of fireflies on SSS+Volume

Related Objects

Mentioned Here
T48383: Cycles Smoke/Fire render procudes NAN pixels
rB2cfadecf97b8: Fix Cycles emission node being unnecessarily tagged as spatially varying.

Event Timeline

YAFU (YAFU) created this task.Jun 2 2016, 2:30 PM
YAFU (YAFU) raised the priority of this task from to 90.
YAFU (YAFU) updated the task description.
YAFU (YAFU) added a project: BF Blender.
YAFU (YAFU) edited a custom field.
YAFU (YAFU) added a subscriber: YAFU (YAFU).
Sergey Sharybin (sergey) claimed this task.Jun 6 2016, 3:25 PM
Sergey Sharybin (sergey) lowered the priority of this task from 90 to 50.
Sergey Sharybin (sergey) changed the task status from Unknown Status to Resolved by committing rB14f9a5aa1de8: Fix T48571: Cycles/GPU - A lot of fireflies on SSS+Volume.Jun 6 2016, 3:56 PM
Sergey Sharybin (sergey) added a commit: rB14f9a5aa1de8: Fix T48571: Cycles/GPU - A lot of fireflies on SSS+Volume.
Sergey Sharybin (sergey) added a comment.Jun 6 2016, 3:58 PM

Fixed fireflies on GPU. Remaining ones i think are related on rB2cfadec which made homogenous volume integrator to be used (which is correct here) combined with T48383. So as a part of bugfix of this particular report there's not much to do now, other issues hopefully will be fixed with the report i've mentioned above.

YAFU (YAFU) added a comment.Jun 6 2016, 9:00 PM

Thank you. Now there is no fireflies and CPU and GPU render result match.

Sergey Sharybin (sergey) added a commit: rCa44c454e1d16: Fix T48571: Cycles/GPU - A lot of fireflies on SSS+Volume.Jun 8 2016, 11:20 AM