View Full Version : Getting 3D shadows into Nuke

02-11-2013, 11:49 AM
Hello. I tracked a shot in Nuek and exported a card and camera move into Lightwave. The card represents the side of a building that I want to attach a 3D object onto. I've rendered out the 3D object as an image sequence compositing it into the scene. I disabled the card inside of Lightwave so that it does not render on the output. Right now I'm faking the shadows on the building from the object but I would love to get the natural looking shadows out of Lightwave onto the building. What is the best way to go about this? I was thinking of just texturing the card with the buildings image and comping the entire render into the scene but there must be a better way to do this.

Any ideas?

02-11-2013, 02:09 PM
You could mock up matching geometry and assign the shadow catcher node.

02-12-2013, 01:52 PM
Great. Thanks.

02-13-2013, 12:19 AM
Hmmm I know I wrote a reply to this once, but I don't see it here now.

You can use the compositing buffer export (image processing panel) to save the shadow buffer. That will give you an image or image sequence where everything is black except for the shadows. You can invert that and multiply it over your background in nuke or (even better ) use it as a mask or matte for a color correction or brightness or gamma or whatever tool you use to darken an image in nuke.