gawain presents problems when particle
Open, ConfirmedPublic

Description

In Blender 2.8, the particle drawing code seems to be stressing the gawain buffer allocation.

If you open the file:


And play around with it (e.g., rotate the view), you get:

The file is simply a cube with 50,000 particles displayed as circles.

Details

Type
Bug
Dalai Felinto (dfelinto) triaged this task as "Confirmed" priority.

I can confirm this bug in Windows 10 compiled in VS2015 64bits, but it's something that I have seen not only using particles.

Sometimes, I get weird results using differents GPUs, but it's not easy to determine when or why. Lately, with last versions the error doesn't appears as easily as before, but it's not solved yet.

No problems on Mac, tested on Intel and NV. Trying Windows next...

After more testing -- zoom/rotate viewpoint, run animation -- I'm still not seeing this problem.

Windows 10, VS2015 on Intel 620
Windows 10, VS2017 on AMD FX-9800P

On what GPUs do you see the problem? Does debug vs. release build make a difference?

We tested on Debug build + Linux + Nvidia (Closed source driver) and the bug is happening on 2 machines: My laptop (GTX960m) and Dalai's desktop (Some Quadro). Will try release build.

It has the same problem in Release build (Linux)

Renderer: 'Quadro K6000/PCIe/SSE2'
Vendor: 'NVIDIA Corporation'
Version: '4.5.0 NVIDIA 375.26'

I get the problem as soon as I open the test Blender file.

I tried in a Linux box with a highend ATI and it doesn't happen either.

Renderer: 'AMD Radeon (TM) Pro WX 7100 DUO Graphics'
Vendor: 'ATI Technologies Inc.'
Cersion: '4.5.13468 Compatibility Profile Context 16.60.3'

Thanks for the info! I suspect this is a buffer alignment/padding issue. I'm talking to someone from NVIDIA tonight (local C++ meetup) and will ask him for details.

@Antonio Vazquez (antoniov) do you see this only on NVIDIA?

@Mike Erwin (merwin) Tested in Windows 10 GTX660 and get the error in Debug and Release compiled with VS2015 64bits. The compilation was without CUDA support in Cycles.

Vendor: NVIDIA Corporation
Renderer: GeForce GTX 660/PCIe/SSE2
Version: 4.5.0 NVIDIA 376.53

What can I do to provide you more information?