Surface that is invisible, but accepts light... Is this possible?

CreativelyMe

All:

Is it possible to create a surface that accepts and displays light but is invisible other than where the light (or shadow, for that matter falls).

I am working on a specific video element at the moment which is why I ask, but being able to display light / shadow values (against say a floor) without displaying the surface other than where the light/shadow hi, is something I could use everyday.

My sense is that this may be a question that's been asked and answered... I've Googled quite a bit, but I'm finding it hard drill into this specific question.

Thanks

Ostadan

The magic search term is "shadow catcher'.

CreativelyMe

Shadow Catcher...

Got it!

Thank you!