View Full Version : How to mix live + cg

05 May 2003, 11:14 PM
Hello, may be my question is pretty stupid but i havent been able to mix 3d + live action. I want my 3d model to go behind some columns i have in a video clip. How do I do this. I have done some
pictures using matte but i want to do it in a motion clip.

05 May 2003, 11:25 PM
Originally posted by la7sombra
I have done some pictures using matte but i want to do it in a motion clip.

You make a moving mask in a compositing program like Combustion or After Effects where you keyframe the mask at each frame so that it follows the foreground shape.

05 May 2003, 11:37 PM
So if i want a a model go behind a real tree wich is affected by wind i have to mak everyy leaf and animate tge mask???

05 May 2003, 11:55 PM
yep, thats why compositors all have bug eyes, pale faces & scrawny necks - its the long hours roto-ing out trees... ;) A good tip though is break it up, make one mask for the trunk, then another for each branch & animate them separately - it will be a lot easier & save you a lot of time...

05 May 2003, 06:30 AM
Hey thanx man I think this is gonna take like 20000 years to complete, well i better get started then, thanx again.:buttrock:

05 May 2003, 01:02 AM
you can always shoot the tree against a nice blue sky and key it out, thats one option.

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