Combining Render Layers Problem

Tproductions · February 20, 2013, 9:39am

Hi,
I was just making a short animation of a space Battle and was compositiong the starship engines and found that when I joined the two render layers together with a MIX node at factor 0.5 the engines would show through the ship. I have tried Overlay and screen nodes but the results were much the same.

Any help would be much appreciated,
Tom

Attachments

Tproductions · February 20, 2013, 9:41am

I am also using the blender internal renderer in blender 2.65,
Tom

sundialsvc4 · February 20, 2013, 3:42pm

Use “Alpha Over.” The image of the engines needs to be masked by the ship. Also see “Z-depth.”

Tproductions · February 21, 2013, 2:00am

Thanks for the reply, do I use nodes to do this?
Tom

Tproductions · February 21, 2013, 2:16am

Ive tried to use the alpha over and it works from behing but from some angles I get the same result as before like in the picture(Below)

Tom

sundialsvc4 · February 21, 2013, 6:36pm

You forgot the Alpha! Plug the alpha channel into the Factor input socket and you should be good to go. (This node-type is also sometimes used to achieve simple, uniform translucency … hence, it can be an input mask or a single number.)

“Z-depth” can also be used to distinguish which of two channels is “in front of” the others. Take a careful look at the various compositing nodes. Essential Blender Compositing is also a very good book to read.