Maniphest T48528

[Information] OpenCL issue continued
Closed, Archived
Actions

Assigned To
Sergey Sharybin (sergey)
Authored By
soulfire (vejn)
May 27 2016, 8:06 AM
Tags
  • BF Blender
  • Cycles
Subscribers
Brecht Van Lommel (brecht)
Sergey Sharybin (sergey)
soulfire (vejn)
Thomas Dinges (dingto)

Description

I'm following this thread on AMD dev forums:
https://community.amd.com/thread/200513

It seems if you check progressive refine under Performance tab you can render on GPU,
while without that check it does not render.

Link to the image posted:
https://community.amd.com/servlet/JiveServlet/downloadImage/2-2726256-107171/test_file5.png

Event Timeline

soulfire (vejn) created this task.May 27 2016, 8:06 AM
soulfire (vejn) raised the priority of this task from to 90.
soulfire (vejn) updated the task description.
soulfire (vejn) edited a custom field.
soulfire (vejn) added a subscriber: soulfire (vejn).
soulfire (vejn) added a comment.EditedMay 27 2016, 8:22 AM

Can some of Cycles developers contact AMD developers on
https://community.amd.com/community/devgurus/opencl/content for providing information and debugg feedback ?

AMD developer in the thread https://community.amd.com/thread/200513
is asking for some feedback and additional info to debugg the issue.

Thomas Dinges (dingto) added a subscriber: Thomas Dinges (dingto).May 27 2016, 2:41 PM

Don't see whats needed? In the latest comments the user reported that with old drivers it worked fine.

Aaron Carlisle (Blendify) added projects: BF Blender, Cycles.May 27 2016, 4:39 PM
Sergey Sharybin (sergey) changed the task status from Unknown Status to Unknown Status.May 31 2016, 11:51 AM
Sergey Sharybin (sergey) claimed this task.
Sergey Sharybin (sergey) added a subscriber: Sergey Sharybin (sergey).

This bug tracker is for reproduceable bugs in Blender. For other type of communication please use our mailing list.

The comments there says that information will be sent to driver developers and users there gave them all the instructions already.

soulfire (vejn) added a comment.EditedMay 31 2016, 4:32 PM

Thanks, where is the mailing list ?

Thomas Dinges (dingto) added a comment.May 31 2016, 5:26 PM

The Cycles mailing list is here: https://lists.blender.org/mailman/listinfo/bf-cycles

soulfire (vejn) added a comment.Aug 2 2016, 3:25 PM

User from the thread https://community.amd.com/thread/200513 reported that render passes with drivers 16.7.3 but there are weird stripes and shading involved:
https://community.amd.com/servlet/JiveServlet/showImage/2-2738955-108954/REN2.jpg

test file:
https://community.amd.com/servlet/JiveServlet/download/2738955-50986/test_cat_1673.blend.zip

Sergey Sharybin (sergey) added a comment.Aug 4 2016, 12:08 PM

This particular issue i can not reproduce on Fiji card. However, there where other stripe issues reported, which i can no longer reproduce with latest Blender versions. So it totally worth testing new builds from builder.blender.org.

soulfire (vejn) added a comment.EditedAug 4 2016, 2:40 PM
In T48528#384771, @Sergey Sharybin (sergey) wrote:

This particular issue i can not reproduce on Fiji card. However, there where other stripe issues reported, which i can no longer reproduce with latest Blender versions. So it totally worth testing new builds from builder.blender.org.

Ok, thanks, I'll try with todays build.
7870 is Pitcarin tech, first GCN. Maybe it's due to how first GCN architecture
operates with OpenCl changes in Crimson drivers. AMD reproduced the problem and they've said to fix it.

Crimson will shift toward OpenCl 2.2 in future releases.
https://www.khronos.org/news/press/khronos-releases-opencl-2.2-provisional-spec-opencl-c-kernel-language

soulfire (vejn) added a comment.EditedAug 5 2016, 2:03 AM

@Sergey Sharybin (sergey) ,I suspect that hair particle system causes issues with OpenCl.
At least on AMD 7xxx series (Pitcairn), GCN1.

If object with hair PS is on the scene (it does not have to be in camera view), renders have weird shading issues.

Also, if hair PS is on the scene, message "loading render kernels (this may take couple of minutes)" is always there when you hit Render. Not just the first time.
Canceling render, causes Blender to freeze.

Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).Aug 5 2016, 3:37 AM

To be clear, did you test the latest build from https://builder.blender.org/download/ and are the issues you describe in your last comment happening with that build?

soulfire (vejn) added a comment.EditedAug 5 2016, 4:16 AM

Yes, with latest build.
Now I'm completely sure that hair PS is connected with OpenCl issue.
Reproducing steps:

  1. Cube with hair PS is on scene (not in camera view)

  1. Render result:

  1. Cube with hair PS is on scene (not in camera view) with restrict rendering

  1. Render result (renders fine):

Conclusion: If object with hair PS is on scene, there are some shading issues.

test_hair_ps_1673.blend1 MBDownload

@Brecht Van Lommel (brecht) ,should I ticket new task with specified title hair PS/OpenCl?

Sergey Sharybin (sergey) added a comment.Aug 5 2016, 9:37 AM

It's always good idea to open new reports. It's easier to merge two related reports than to split info from a single one.

Once more thing. Does disabling Hair BVH in the perofmance panel makes any difference to the issue?

Think i have some GCN1 card around so will try to reproduce the issue here later.

soulfire (vejn) added a comment.EditedAug 5 2016, 10:46 AM
In T48528#384881, @Sergey Sharybin (sergey) wrote:

It's always good idea to open new reports. It's easier to merge two related reports than to split info from a single one.

Once more thing. Does disabling Hair BVH in the perofmance panel makes any difference to the issue?

No.
It's possibe this is only driver related with GCN1 cards.