Random Per Island/Math Node GPU Issue

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BlenderBrit
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Joined: Thu Apr 15, 2021 7:19 pm

Random Per Island/Math Node GPU Issue

Post by BlenderBrit » Fri Jun 04, 2021 3:34 pm

Hey Guys,

I'm having an issue with GPU rendering on a particular material setup. Basically a RandomPerIsland material for distributing floorboards. It works flawlessly on CPU rendering but completely falls over on GPU, with either OPENCL or CUDA.

Information:
Blender 2.93LTS
LuxCore 2.6 Daily (Downloaded same day as this post)
RTX 3090 (Latest Drivers)

Images:
The node setup:
nodes.jpg
CPU Render (Correct result):
CPU.jpg
GPU Render (hmmm....):
GPU.jpg

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TAO
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Re: Random Per Island/Math Node GPU Issue

Post by TAO » Fri Jun 04, 2021 3:54 pm

That's the same issue I see with the math node on GPU that already report in the past. With CPU there is no problem but with GPU the material going to be dark and black in some parts as you can see in your final render too.
Same behavior with 3dsmax plugin and LuxCoreRender stand-alone version.
Omid Ghotbi (TAO)
Latest build Download link👇👇
https://github.com/LuxCoreRender/MaxToLux/releases
Last update information
https://forums.luxcorerender.org/viewto ... 590#p30154

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Dade
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Re: Random Per Island/Math Node GPU Issue

Post by Dade » Fri Jun 04, 2021 4:03 pm

I need a test scene, a plane with your floor material.
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BlenderBrit
Posts: 8
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Re: Random Per Island/Math Node GPU Issue

Post by BlenderBrit » Fri Jun 04, 2021 4:45 pm

Sure, no problem. Here is the scene file, the textures have been packed.

https://drive.google.com/file/d/1I7U6OT ... sp=sharing

BlenderBrit
Posts: 8
Joined: Thu Apr 15, 2021 7:19 pm

Re: Random Per Island/Math Node GPU Issue

Post by BlenderBrit » Sat Jun 05, 2021 10:11 am

Added a github report of the error:
https://github.com/LuxCoreRender/BlendL ... issues/689

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Dade
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Re: Random Per Island/Math Node GPU Issue

Post by Dade » Sat Jun 05, 2021 11:22 am

BlenderBrit wrote:
Fri Jun 04, 2021 4:45 pm
Sure, no problem. Here is the scene file, the textures have been packed.

https://drive.google.com/file/d/1I7U6OT ... sp=sharing
Actually, it is a problem related to bump mapping, if you disconnect the floor bump map, CPU and GPU rendering is the same. I'm checking what is going on.
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TAO
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Re: Random Per Island/Math Node GPU Issue

Post by TAO » Sat Jun 05, 2021 11:53 am

Dade wrote:
Sat Jun 05, 2021 11:22 am
BlenderBrit wrote:
Fri Jun 04, 2021 4:45 pm
Sure, no problem. Here is the scene file, the textures have been packed.

https://drive.google.com/file/d/1I7U6OT ... sp=sharing
Actually, it is a problem related to bump mapping, if you disconnect the floor bump map, CPU and GPU rendering is the same. I'm checking what is going on.
Exactly, it appears in bump map, and the problem will show up in GPU render and not CPU.https://forums.luxcorerender.org/viewto ... f=4&t=2995
file.jpg
I remember if I use Non-Color Data image for bump there was no problem with GPU renderer.
Omid Ghotbi (TAO)
Latest build Download link👇👇
https://github.com/LuxCoreRender/MaxToLux/releases
Last update information
https://forums.luxcorerender.org/viewto ... 590#p30154

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Dade
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Location: Italy

Re: Random Per Island/Math Node GPU Issue

Post by Dade » Sat Jun 05, 2021 12:16 pm

Dade wrote:
Sat Jun 05, 2021 11:22 am
BlenderBrit wrote:
Fri Jun 04, 2021 4:45 pm
Sure, no problem. Here is the scene file, the textures have been packed.

https://drive.google.com/file/d/1I7U6OT ... sp=sharing
Actually, it is a problem related to bump mapping, if you disconnect the floor bump map, CPU and GPU rendering is the same. I'm checking what is going on.
I should have fixed the problem, it was affecting Add/Subtract texture nodes when used for bump mapping. The fix will be included in the next automatic build.
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BlenderBrit
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Re: Random Per Island/Math Node GPU Issue

Post by BlenderBrit » Sat Jun 05, 2021 3:28 pm

Excellent, I'll check out the new auto build when it pops out.

Thanks for the quick turnaround time on this! Quite new to LuxCore and this is very encouraging to see.

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