Rendering shadow/reflection but not the plane itself
 

Ok. So I have an object that's lying on a plane, casting a nice shadow - or creating a nice reflection. I want to use the finished image on the web.

But, we have a catch 22 here. In order for Maya to render a shadow or a reflection, it needs to render the entire plane beneath the object, meaning that there won't be an alpha channel, meaning that I can't use the resulting image on any background.

So, how do I render only the shadow/reflection on a surface and not the surface itself? Can it even be done? I want the shadow to be a part of the alpha channel, so it can be used on any background. Ditto for a reflection.

Is it possible?

Dont thinnk you can for refelctions, I usualy do a refelction pass sepperate with all objects set to 100% refelctive, each object on a sepperate layer and then render and compsisite.

You should have an option to render just the shadows in the render layers options.

Gster: Dont drink at noon! :)

Use the backgroundshader:beer:

or just check off primary visibility in the render options of the object.

i think that will work