Rendering shadows, for compositing
 

Does anyone know how to render out a shadow, like from the sun, to my spaceship, and the shadow will appear on the Live Action ground that was filmed already. Does anyone understand?

Yep:)

This is what the USE BACKGROUND shader is for.

Check out the Docs for usage.

Basicly, in Maya, you create a piece of geometry to "catch" the shadow from your light so it appears to be falling on an area of your bg plate footage.

That piece of geometry is not rendered, but the shadow IS:)

make sure you go into the shader properties of the use background and turn off its reflectivity if you are just using it for the ground.. I have made the mistake of not noticing that, and it can really screw up the ground. :)
Brian

Good point Brian!

...hehe, I made that mistake in the past as well:)

weird once again Simplymaya didn't tell me about this reply until izzys second post. Either way thanx again guys, hopefully i can make some shadows in the movie now!

Not sure about the email notification, I never use it, I always have SM open in ma browsa, so I can just keep hitting refresh in the "new posts search page", and if the last person who replied to a post changes, then I check it out:)

But on your movie, cool! I'll check your thread occasionally to see when you have a sample of the cg shadow footage available:)

also check out the smoke, i used a shader from Pure Mornings Stuntplanes and it looks cool! (there is an animation)