Material Wrapper - rendering shadow pass for live action comp with backside normals

[mschreck]

Hi,

I´m looking for a feature as described in this video:

https://youtu.be/_5PqNrrXKJY?t=184

I have a very distorded shadow catcher floor object (photogrammetry) and would like to avoid having "holes" in my shhadow pass.
Is there a way to achieve that in Vray?

many thanks

Mathias

[fixeighted]

In Max the edit mesh modifier/unify normals works. Hopefully there is a similar method in Maya, as this is the only method I can think of at the moment.
If not then upload the asset and I'll convert it, if you don't have access to Max.

[mschreck]

thanks I will give it a try!

[mschreck]

ok i just checked the unify normal thing in max. It´s actually not my issue in this case. The floor mesh is fine. The "holes" I have are not actual holes or broken normals in the mesh but areas inside the shadow where faces are opposite of the light.

So the shadow pass renders perfectly correct in a technical point of view: polys facing away from the light are excluded from the shadow pass.
As this might be correct it still is not ideal for comping my live action plate. I would like to be able to remove areas in shadow in comp, not at render time.

If I remember correctly the puppet shader "p-shadow" for mental ray had a feature like that as well...

[fixeighted]

Ah ok, I see what you mean now. I will try to see what I can come up with unless someone else here beats me to it