MirHadi
			  Nov. 29, 2021 17:58:04
		 	 
			
				Hello
I have a simple scene a sphere and a grid plane, just want to test how I can render out a ground plane as a shadow catcher (matt object, with shadows on it).
I can't find the way to do it in solaris and karma Xpu.
please let me know how I can do it.
thank you in advance
			
		 
		
			
			  mestela
			  Nov. 30, 2021 00:49:18
		 	 
			
		 
		
			
			  MirHadi
			  Nov. 30, 2021 04:07:26
		 	 
			
				It should work as the doc says but unfortunally the shadow layer is empty  with karma XPU!
It works with karma by the way. but I need XPU version for faster render.
PS: That's the principed shader inside Backgourd plate subnet that makes it uncompatible with XPU version.
			
		 
		
			
			  jsmack
			  Nov. 30, 2021 11:16:42
		 	 
			
				MirHadi
It should work as the doc says but unfortunally the shadow layer is empty  with karma XPU!
It works with karma by the way. but I need XPU version for faster render.
PS: That's the principed shader inside Backgourd plate subnet that makes it uncompatible with XPU version.
XPU doesn't support the necessary AOVs yet, so it's not possible.
			
 
		 
		
			
			  TangheStudent
			  Feb. 17, 2022 09:46:29
		 	 
			
				Annyone know how to apply maps to the channels ?
			
		 
		
			
			  Tser
			  Jan. 29, 2023 17:25:31
		 	 
			
				Hi Guys, I'm now moving to XPU from many years of using Arnold, XPU is such a great renderer, the only issue I have with my renders is the Shadow Matte, I have been using a plane with a texture on it's Opacity channel to blend the plane into the Dome Light's map so I can catch the shadows, this works o.k. for still shots, but takes quite a bit to set it up.
Is there any eta on when a shadow catcher will be added to XPU?
Again, great work on this beautiful renderer.
T.
			
		 
		
			
			  brians
			  Feb. 2, 2023 21:59:00
		 	 
			
				Tser
Is there any eta on when a shadow catcher will be added to XPU?
The next version of Houdini will have much better support for shadow mattes in XPU
namely
- shadow LPEs (eg "shadow;C.*")
- Holdout LPEe (eg "holdout;C.*"or "holdout;C<..'torus'>.*"etc...)
			
 
		 
		
			
			  eaniix
			  July 29, 2023 16:55:42
		 	 
			
				brians
Tser
The next version of Houdini will have much better support for shadow mattes in XPU
did you refer to H20 or a previous 19.5 build? I still can't get shadow mattes to work in 19.5.605
			 
		 
		
			
			  brians
			  July 30, 2023 22:52:28
		 	 
			
				eaniix
did you refer to H20 or a previous 19.5 build? I still can't get shadow mattes to work in 19.5.605
Not H19.5
Sorry I should have said "the next 
major version of Houdini"
			
 
		 
		
			
			  Mirko Jankovic
			  Nov. 11, 2023 15:18:43
		 	 
			
				Hi, any update on this topic by any chance? Running into same issue, need shadow matte on ground obj, but having hard time getting it. Any updates?
This is such a basic thing shouldn't be that hard 
 
			 
		
			
			  EdganHomt
			  Nov. 18, 2023 14:57:26
		 	 
			
				I am struggling to setup the shadow catcher with XPU, background plate  doesn't work with it, any directions would be appreciated it.
			
		 
		
			
			  tomtm
			  Nov. 27, 2023 07:31:33
		 	 
			
				Yes I am also struggling with a proper shadow catcher setup. 
Maybe someone could post a .hip?
I would wish a shadow catcher shader, something easy to apply. Isn't this an essential function?
			
		 
		
			
			  Mirko Jankovic
			  Nov. 27, 2023 07:42:50
		 	 
			
				Still no luck on my side....
			
		 
		
			
			  Tser
			  Dec. 8, 2023 00:18:25
		 	 
			
				Has anyone been able to get a shadow catcher functionality in Houdini 20, or is it the same as 19.5?
			
		 
		
			
			  jsmack
			  Dec. 8, 2023 00:57:33
		 	 
			
				20.0.548	Fixed a bug in Karma XPU to get Background Plate node working
Maybe give it another try?
			
 
		 
		
			
			  tomtm
			  Dec. 10, 2023 17:31:54
		 	 
			
				jsmack
20.0.548	Fixed a bug in Karma XPU to get Background Plate node working
Maybe give it another try?
Could you setup a shadow catcher now? I can't. 
Is there probably a .hip to show?
I can't get it.
			
 
		 
		
			
			  brians
			  Dec. 10, 2023 21:30:45
		 	 
			
				How about this?
It's a basic scene I've used for testing.
Here are the docs for the background plate too
https://www.sidefx.com/docs/houdini19.0/nodes/lop/backgroundplate.html [
www.sidefx.com]
			
 
		
			
			  tomtm
			  Dec. 11, 2023 16:12:54
		 	 
			
				brians
How about this?
It's a basic scene I've used for testing.
Here are the docs for the background plate too
https://www.sidefx.com/docs/houdini19.0/nodes/lop/backgroundplate.html [www.sidefx.com]
Thank you for the sample. 
Is it also possible to have no plate image just transparency directly saved out like in the pitures below. 
In this scene I had a shadowCatcher Material on the floor.
			
 
		 
		
			
			  Tser
			  Dec. 11, 2023 17:29:43
		 	 
			
				When I set the render engine to XPU the render takes quite a bit longer than CPU, and I don't think you can get the same effect as a shadow matte (Shadow Catcher) with an environment light hdri, unless this ability is hidden somewhere.
			
		 
		
			
			  tomtm
			  Dec. 11, 2023 17:40:02
		 	 
			
				Tser
When I set the render engine to XPU the render takes quite a bit longer than CPU, and I don't think you can get the same effect as a shadow matte (Shadow Catcher) with an environment light hdri, unless this ability is hidden somewhere.
I think it would be essential for later compositing where you load the background footage. 
It would be cool to have a ShadowCatcher Material.