Render Layers

I’ve made a fire effect, using composite nodes. However, I just want the nodes to effect the fire, not the WHOLE render…

I suspect using render layers will get me the desired result.

Lets say I have sphere on layer 2 (named other), and fire on layer 1 (named fire), how can I set up render layers to make layer 1 effected by the composite nodes only and layer one unaffected?

EDIT: Here is a picture of my nodes, with render layers…

And heres a copy of the blend…


fire.blend (255 KB)

I’ve made some progress, but its still not correct…

Gonna keep playing with it. I want the sphere to show up in front of the flame, and the other sphere to show through the flame.

tough one. I think the proper way is to use a Z-combine node but i’m not too sure how you would do it.
I managed to have a sphere behind showing through using alpha-over. To do that I needed to first re-set the alpha chanel that had been lost. An image is worth a thousand word so:

The inconvenient of using AlphaOver instead of z-combine is that you have to put what’s in front of the fire and what’s behind it on two separate layers.
If you’re planing to animate it and have stuff moving from in-front to behind (and vice-versa) then you must use z-combine.

Hope that helps :slight_smile: