Rendering light & shadow

[bilicsko]

Hi,

I am pretty new to Houdini and I've got a noob question: how can I only render the light and shadow on the ground without the ground?

Thanks a lot,

Máté

[galagast]

I'm not sure if this is the proper way to do this. Only works with Raytracing.

VIEWPORT:

RENDER:

MATERIAL: (for the ground object)

FILE:
Houdini 16.0.731 Indie - light_shad_only.zip

Edited September 21, 2017 by galagast

[bilicsko]

Thanks for the effort,

Unfortunately I could not open your hip file with H15.5 but I tried to set this material up but no success so far. I'm not sure if the constant type is correct (or any other value)

[galagast]

Hi, here's the same setup in H15.5.717 - light_shad_only_H15.5.zip

[bilicsko]

Unfortunately it does not work properly in my setup. (And also couldn't render your scene because of an error message.)  I guess I'll have to find another method.

Thanks again

[fencer]

Try this

light_shadow_render_v01.hip

[davpe]

just use shadow matte material preset. that is the easiest way I guess.

[bilicsko]

fencer unfortunately I can't open h16 file

dave: Yes I can get the shadow in alpha channel but not the light. Can I get that as well somehow?  *Maybe I figure it out

 

Edited September 22, 2017 by bilicsko

[davpe]

why don't you do two renders and then comp them together? sure you can get both in one render but that will require some setting up that you'll have to figure out

[galagast]

Haha yes, I suppose I was complicating the initial question, my apologies.

Normally, as Dave mentioned, you would have to render it out in separate passes. One for the light, and for the shadows, and a beauty pass, possibly with matte objects.
Fencer's file is doing just that (except for the beauty pass still showing the ground geometry.. which can easily be turned into a matte object). If you can download H16, you'd best check out his file