matte object reflections

[sdds]

I'm sure this has been covered before but I can't find any info on it.

 

Is there a way to include reflections in a matte object pass. Currently I've been using the sphere fade technique to pick up an objects reflections on say the matted ground plan. How would others go about this?

[viv_arun]

thinking i have understood ur query,here is an example.

 

In an animation wlakthrough u want a car to travel into the parkin lot.

but for postpro work u want to render the car alone in PNG with all the reflection,refraction.

 

for this u need to select evry object except the car and right click in the viewport...goto object properties..in tht un check visible to camera.

 

this way ,u ll get the relfection ,refraction of the environment.but u need not hv to render the whole scne.