matte/shadow with opacity map

[Chad Warner]

Hi all-

 

I am trying to render an animation of only moving cars that I can composite on top of another animation using premiere or after effects.

 

I have been using matte/shadow materials for everything, but the problem I have is there are opacity mapped shrubs (planes with an bitmap and an opacity map) in the foreground. What I can't figure out how to do is make the plane objects obscure the cars as they go by, but only where the opacity map tells it to, not the whole plane object.

 

Anyone have any ideas?

 

-Chad

[ITryMyBest]

chad-

 

Since you are already compositing in after effects, you could render the cars and background leaving only the shrubs in front turned off. Then render the scene with only the shrubs turned on. Place the 'shrubs movie' on top of the 'cars and background' movie in after effects and everything should work out. The main thikng to remember is to make sure you keep the alpha channel in the 'shrubs movie'

 

Hope this helps

[Chad Warner]

That was going to be my solution, only if there was no other way to do it. I was hoping there was another way to go about it though.