Make shadow catcher surface visible in mirror

Hey

when you have a plane and set it to only catch shadows you do not
see it inside the mirror reflection. It gets rather gray instead of white
when it is a white surface.

Anybody knows a trick to make it only cast shadows but still show inside
the mirror reflection?

what about starting out with it solid, then texture baking the mirror, then setting the mat back to onlyshadow or whatever, and loading the baked image onto the mirror as a shadeless uv texture?

Another idea would be to use renderlayers.
Make a copy of your plane with another Material and move it in a second layer.
Activate both layers in the 3DView, but exclude the second layer from your renderlayer.
Because renderlayers do not respect mirrorreflections, you will get the reflections of the object in the second layer, but not the object.
Make shure the second plane is a bit under the shadowplane to stay with the correct shadow.

Samplefile

Attachments

refl_only.blend (241 KB)

mh both sound good.

shadow baking is a god idea - you just canot move the shadow casting lamp later.

I’m assuming you’re using ray reflection. You could switch to using Env Maps, but that may not be appropriate to your piece.

Patels tip works the best.

I did not think about render layers - silly me.
I used it for shadow work but did not make the logical connection to ray mirror …

Here is a new rendering:
http://www.postimage.org/gx1yj02S.jpg

It is still a little flat because it only uses AAO and I have only one area spot.
for a stylistic rendering it does the job.

The backdrop isnt working fine currently because of the view angle …
I might just create a mesh and put it into the back.

Mh the shadow is only an alpha value which means it is gray.

We can now set the color of a shadow - but it seems when you use
the shadow catcher trick, the color gets lost - well because the
shadow itself is being transferred into a alpha map, which is color less.

Anybody has an idea how to keep the color?