Separate shadow?


I apologize if this should be in the Rendering Forum, but I also would like to know how to composite.

  1. in Render Layers, how do I make a pass that is only the shadow on white? There are blocks for scene and block for layers…I’m confused as to which ones to select

  2. to composite a shadow, I have over half the rendered image as transparent. What is the node I need to use to fill the rest of the transparency?

Thanks everyone for your help!

  1. You have a render passe that is called Shadow. Just activate it and you’ll get black shadow on white background. But it works only with lamps, not objects that emits shadows with an emission shader.

  2. Put anything you want behind with the alpha over node. Can be an image texture, a sky render, …

Thanks VincentG! When I use a Shadow Pass (checking the box in Render Layers) - I also will get shading on the robot. I only want the shadow on the ground… How can I remove the robot’s body shading and only keep the dark areas on the plane?

Excuse me if this is stretching into the realm of Rendering…
Is this how my Render Layers should work if I want a separate ground plane render with shadow (but without the Robot)?

I found one workaround: I applied a New Material to the Robot and checked “Shadeless”
(btw I am using Blender Internal)

Oh I guess I also could have checked Shadows>Cast Only and unchecked everything else on the robot

Yes you can do it in several ways!
My personal preference is to separate layers like you have showed :slight_smile: