• Maxon Cinema 4D

  Object that creates alpha

  Posted by Max Zachner on April 25, 2011 at 12:17 pm

  Hi!

  My problem is a little hard to discribe (especially in English), but here we go.

  I have a scene with a building with windows. I want to render the scene to composit it with real footage of someone behind the window.
  Is there a way to create a plane or whatever that creates alpha for its position? I don’t want to see the rear of the building, but have an image that is transparent inside the windows, so I can composit it with the footage inside AfterEffects.

  Hope that was understandable… 🙂

  Adam Trachtenberg replied 15 years ago 3 Members · 3 Replies
• 3 Replies

• 

  Dale Anderson

  April 25, 2011 at 2:50 pm

  Yes, I just did this exact thing myself. You crate a plane and apply the video footage to the plane as a material.
• 

  Max Zachner

  April 25, 2011 at 3:21 pm

  That was my first Idea too, but I’d like to have the possibility to adjust the layers seperately while doing color correction etc.
  Oh, but I can render them seperately, can’t I?
• 

  Adam Trachtenberg

  April 25, 2011 at 7:35 pm

  If your building is just a facade with no walls inside you could give it a compositing tag and assign an object buffer. Then add the same object buffer in Render Settings (Render Settings>Multipass>Add object buffer).

  That won’t work if there are interior walls. In that case you’d have to put planes in the windows and assign an object buffer to the planes.

Reply to this Discussion! Login or Sign Up