Cycles: GPU Optix kernel loading with Bevel/Ambient Node. #102162

New Issue

Robert Lechl · 2022-10-30T13:13:34+01:00

Robert Lechl commented

2022-10-30 13:13:34 +01:00

XMGNEO17 Laptop AMD Ryzen9 5900HK Radion.
Operating system: Windows 11 Home. 21H2
Graphics card: Nvidia Geforce RTX 3080 Laptop GPU. 16 GB VRAM.

Blender Version
Blender 3.2-3.4 show the error. Blender 3.1 and before not.

Short description of error
The error happens when ever an Ambient Occlusion or Bevel Node is used and connected in a shader and GPU option OPTIX is enabled for rendering in Cycles. It does not happen with CUDA or CPU.
Blender will start render process and stops with the line: Preparing for rendering, this can take time.. etc. At that point the UI is still working, but will freeze after trying to cancel rendering. Blender can only be forced to shut down. Scene changes are lost.

Exact steps for others to reproduce the error
The but is very simple to reproduce:

Open Blender and apply a shader to the cube.
Add a bevel/Ambient node to the shader and connect it to any input. Doesn't really matter which.
Enable Optix in the preferences and set cycles as render. Make sure its set to use GPU.
Switch viewport to preview render.
Blende will stop preparing the scene and won't move further. Its UI is still reacting until trying to stop the process.

XMGNEO17 Laptop AMD Ryzen9 5900HK Radion. Operating system: Windows 11 Home. 21H2 Graphics card: Nvidia Geforce RTX 3080 Laptop GPU. 16 GB VRAM. **Blender Version** Blender 3.2-3.4 show the error. Blender 3.1 and before not. **Short description of error** The error happens when ever an Ambient Occlusion or Bevel Node is used and connected in a shader and GPU option OPTIX is enabled for rendering in Cycles. It does not happen with CUDA or CPU. Blender will start render process and stops with the line: Preparing for rendering, this can take time.. etc. At that point the UI is still working, but will freeze after trying to cancel rendering. Blender can only be forced to shut down. Scene changes are lost. **Exact steps for others to reproduce the error** The but is very simple to reproduce: 1. Open Blender and apply a shader to the cube. 2. Add a bevel/Ambient node to the shader and connect it to any input. Doesn't really matter which. 3. Enable Optix in the preferences and set cycles as render. Make sure its set to use GPU. 4. Switch viewport to preview render. 5. Blende will stop preparing the scene and won't move further. Its UI is still reacting until trying to stop the process.

Robert Lechl commented

2022-10-30 13:13:34 +01:00

Added subscriber: @RobertLe

blender-admin commented

2022-10-30 13:13:34 +01:00

#104342 was marked as duplicate of this issue

blender-admin commented

2022-10-30 13:13:34 +01:00

#104231 was marked as duplicate of this issue

blender-admin commented

2022-10-30 13:13:34 +01:00

#100395 was marked as duplicate of this issue

Pratik Borhade commented

2022-11-02 05:36:11 +01:00

Added subscriber: @PratikPB2123

Pratik Borhade commented

2022-11-02 05:36:11 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Pratik Borhade commented

2022-11-02 05:36:11 +01:00

Thanks for the report. Not a bug I would say.
I'm able to confirm the long waiting time but it compiled after some time.
Wait for render kernels to load. Because interrupting the process does result into the freeze.

Thanks for the report. Not a bug I would say. I'm able to confirm the long waiting time but it compiled after some time. Wait for render kernels to load. Because interrupting the process does result into the freeze.

Robert Lechl commented

2022-11-02 13:16:42 +01:00

Interesting case.
I tested my work scene and got no response even after 15 min wait time.
I tested an empty scene with a cube and did through a preset material on it.. no response in 5 min (So I shut it down)
Then I did just add a bevel node to a cube.. simple scene. 3 min later the rendering started.
So once compiled it worked on the other scenes too.
I then switched to Blender 3.3.1 and again the same process. However it took this time 4 min to start render the cube.

I would say, this is clearly a problem.

Because its not clear why I take different time depending to scene.
It didn't happen in 3.1, or with Cuda, M1 or other hardware.
It need to be repeated for each version of Blender.

A solution would be waring the user as soon as he switch to Optix for the first time, that he need to do a test run to enable Bevel and Ambient Occ. node. Maybe that could be done right when Optix is enabled first time. Somehow this information must exist somewhere in the system.

Interesting case. I tested my work scene and got no response even after 15 min wait time. I tested an empty scene with a cube and did through a preset material on it.. no response in 5 min (So I shut it down) Then I did just add a bevel node to a cube.. simple scene. 3 min later the rendering started. So once compiled it worked on the other scenes too. I then switched to Blender 3.3.1 and again the same process. However it took this time 4 min to start render the cube. I would say, this is clearly a problem. 1. Because its not clear why I take different time depending to scene. 2. It didn't happen in 3.1, or with Cuda, M1 or other hardware. 3. It need to be repeated for each version of Blender. A solution would be waring the user as soon as he switch to Optix for the first time, that he need to do a test run to enable Bevel and Ambient Occ. node. Maybe that could be done right when Optix is enabled first time. Somehow this information must exist somewhere in the system.

Pratik Borhade commented

2022-11-11 06:23:38 +01:00

Changed status from 'Needs User Info' to: 'Needs Developer To Reproduce'

Pratik Borhade commented

2022-11-11 06:23:38 +01:00

Hi, thanks for the update. Checked in 3.2 and prior versions, kernel compiling doesn't happen there.
Some commit between 3.2-3.3 has introduced this. This is one time process so I'm not sure how to bisect.
#100395 and #100246 are probably related.
I'll forward this report to devs for now.

Hi, thanks for the update. Checked in 3.2 and prior versions, kernel compiling doesn't happen there. Some commit between 3.2-3.3 has introduced this. This is one time process so I'm not sure how to bisect. #100395 and #100246 are probably related. I'll forward this report to devs for now.

FLEB commented

2022-12-18 22:16:42 +01:00

Added subscriber: @FLEB