Casting shadows on nothing?

[Deleted User]

In max how can I cast shadows onto a totally transparent object?

I have a photo, into this photo a model will go, and I want to render the shadows being cast by that item, but I just want to have the shadows, not any type of 'floor' as I need the shadows to overly onto the background.

I thought I could cast shadows onto a transparent box or plane, but they dont show up as the box/plane isnt dense enough.

Any ideas?

biotech

Use the matte/shadow material.

[Deleted User]

thanks biotech, thats just what I was looking for