Karma - Point Color (Cd) not rendering with XPU?

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Hello,

When I use XPU Renderer the color attribute does not render (tried as primitive, point and vertex) on a principled shader material. It works fine if render in CPU. Also, if I don't assign any material then XPU *does* use the point colors as expected.

Can anyone confirm this is the case?


Karma is great and so amazingly fast, I can render these at 1920x1080 in 2 seconds! If change Karma to CPU it takes 11 minutes! (330x times slower) So my current workaround is to render on XPU with no material (which is extremely limiting).

I'm very new to rendering in Houdini, is there anything I'm missing to make this work?

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I do not know how you approached coloring these but Adam Swaab explains how to make color work with MaterialX materials here: https://www.youtube.com/watch?v=IyWseMa1yZk&t=5188s [www.youtube.com]

Start watching at 1:29:50
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XPU doesn't use the principled shader, that's for Mantra and Karma CPU
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Kindly share if anyone figured out on how import Cd color attribute to karma xpu?
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Hi.

Cd becomes displayColor in USD. If you have a look at scene graph details you should see it. Best. Mark
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theflatarc
Kindly share if anyone figured out on how import Cd color attribute to karma xpu?

use the mtlx geometry color node
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jsmack
theflatarc
Kindly share if anyone figured out on how import Cd color attribute to karma xpu?

use the mtlx geometry color node

Thanks so much!
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just add a geometry color node! OvO

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Mark Wallman
Hi.

Cd becomes displayColor in USD. If you have a look at scene graph details you should see it. Best. Mark
Interestingly it seems like casing in the name of the variable plays a role. I had a point attribute named `Alpha` I was not able to read with the prim var attribute reader until I renamed the variable to `alpha` and read it as such.
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adam_breach
Mark Wallman
Hi.

Cd becomes displayColor in USD. If you have a look at scene graph details you should see it. Best. Mark
Interestingly it seems like casing in the name of the variable plays a role. I had a point attribute named `Alpha` I was not able to read with the prim var attribute reader until I renamed the variable to `alpha` and read it as such.
same way as Cd becomes displayColor
Alpha becomes displayOpacity

so that may be reason why you can't bind Alpha since it may not exist on the stage under that name
Edited by tamte - Sept. 7, 2023 00:50:22
Tomas Slancik
FX Supervisor
Method Studios, NY
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