Possible to make an object visible in raytracing but cast no shadow?

I have a UV mapped image with alpha in my scene. I don’t want it to cast shadow, but I want it to be visible in raytracing, so that it can be seen in reflective materials. Is this possible?

clicking the “traceable” selection in the material tab makes it cast shadow. Unselecting causes it to be unseen to mirrors.

Any ideas?

You could light it with a shadowless lamp. In old (2.49) blender this involved putting the object on its own layer and setting it that only lamps only that layer would affect it. I’m not certain if 2.5 works the same way.

Hope this helps,
GreyBeard

Thanks GB, But I can make the plane to emit, no need to light it, it just can’t cast shadows, yet still be seen in a mirror. I think the only way to do it is with render layers.

You can put your plane on its own layer with its own lamp set to no shadow and ‘This Layer Only’.
Note that the best solution may be different for you given your specific situation, that’s why it can save other users time and effort if you always attach your blend file to your post.
In the attached blend the imaged plane can be seen in reflections but does not cast any shadows.

Attachments

mirror.blend (157 KB)

I’d upload the blend, but it’s an animation scene file, probably around 200 MB. Tough to pass around. :confused:

Sorry but that doesn’t stop you attaching a stripped down blend file that demonstrates what you are trying to achieve.