Overrides to get alpha out of hair, like in xsi 4

[sirdavid32]

Hello, I´ve got a scene where I isolated a fured animal in it´s own pass for render´s economy´s sake.
I´ve created a pass for the animal with 2 partitions: 1 for the skin and 1 for the hair.
In xsi 4 you´d apply an override to the skin partition turning off diffuse_inuse (and specular_inuse) so that you´d get only your hair being rendered but ocluded by the alpha of the skin.

In 2010 I´m trying the same method, but when I check my render region with alpha only, I still get
to see the entire fur animal silhouette. I only need the hair. I uncheck the override parameters, but
they turn out to make the skin just "dark" and not really trimming the hair to the skin (or face) shape
because it´s still visible (black colored).

I´m using final gathering on this render. What other method do I need to use to isolate the hair, trimmed by the hands or feet and face?

Thanks.
David.

[Hirazi Blue]

Just a guess: Are you sure this is a problem with your pass, not "just" a problem with (the settings for) your render region? Does the problem also occur if you render out a single frame of your hair pass?

[izze]

Put the body in a separate partition with a constant material assigned to that partition. Set the Alpha slider of the constant color to 0. That will give you the hair only with an alpha.

[sirdavid32]

Thank you !! it worked perfectly!!!