Shadow matte?

[grpone]

Hi!

How would I go about to create a shadow matte material? I'm rendering a building against a photo background and want the shadows on the ground plane but not the plane it self to show.

In the Max version of Vray there seem to be a matte option in the "material wrapper". Anything similar in the Rhino version?

Best, Fredrik

[grpone]

Re: Shadow matte?

Hi again,

Now I've rendered a shadow pass of the scene to try to do it that way. Problem is, the mask is very rough. Ideal would be to have the (soft) shadows affecting alpha.

Sorry if it's a basic question, I'm new to this. I'd greatly apprecitate some help!

Regards, Fredrik

[dalomar_cg]

Re: Shadow matte?

We actually don't have a shadow material yet. I was working on messing with one with the Shadow pass, but as you found out, its very grainy compared to the rendered result. One of the things I did, was to render out two passes...one regular and one for the shadows. The shadow pass I removed most of the materials to make it faster, as well as increase AA and the shadow subdivisions.

EDIT: It appears that in the new SR, the shadow pass seams much less grainy(at least from what I remember). I just did a quick test and didn't actually have to do a second pass. As far as what I did in ps, I basically loaded the shadow pass in as a selection and put that as a layer mask onto the background (I separated the object from the ground plane before). After that I just messed with levels (with the layer mask active) to tweek the appearance of the shadows...sorry for the background image as it was just what I had lying around.