Alpha and shadows not working properly in raytrace?

Hey all.

I’ve been working on a scene for quite a while now, and everything’s been okay up until now.

See, I’m rendering a desk with a few things on it, and one of the things is a sheet of paper with a couple corners torn off. Problem is, every time I try and render the image with raytrace and shows on, it renders area of the desk under it the whole plane black because it’s making the shadow for the entire plane, and not just the 100% alpha area as it should be!

I’ve tested a few different things like turning AO off, raytracing off and shadows off. It’ll do it when raytrace and shadows are on, so I can be sure it’s a shadow problem with the raytracer. (plus I pulled it way off the table and it was perfectly transparent)

So, how would I go about making it raytrace the shadow for the 100% alpha area, and not the 100% alpha area and the 0% alpha area?

If I wasn’t clear enough, I can post a pic of what’s going on.

i believe you turn on raytransp on the paper and hit the traceable button (material window to the right of Spec/Hard) on the object you want to receive the shadow.

See that’s the weird part. BOTH tracable and raytransp are set to on. :-?

really? hmm…

the traceable has to be turned on for the desk object, not the paper object.
if thats already done then im not sure. maybe posting the blend would help?

Wait… have traceable set to on for both, or just the desk?

I think “TraShadow” needs to be set for the material recieving the shadow.

Hahha! That’s it!

Thanks man, I knew there must be a way :smiley: .

you need it on the desk AFAIK. it won’t matter if you have it on the paper. traceable means that it will take the alpha of the shadow casting object into account when drawing the shadow (i believe).

doh! :expressionless: thats what I meant lol, not traceable.

whoops, my bad.