question about material and Ambiant occlusion


I followed the following chrome tutorial :
All is working fine as explained.
But I want to make some changes on my plane where Suzanne is laying onto.
I want my plane to reflect Suzanne but not the sky.
How do I do this?

When I set the Ray Mirror option for my plane it is indeed reflecting suzanne but also the angle map image of the sky. Is it possible to set the ambiant occlusion so that it lights only the monkey and doesn’t influence my plane? How?


you can do this with render layers in the node compositor

thanks for the guideline!
It is yet a little bit complicated but I think the following tuto will help :

I don’t manage to get the expected result with nodes (probably I don’t master it enough).:frowning:
I want the plane not to reflect the sky but only the monkey. Is there not any way to limit the sky’s reflection only to the monkey ?

you can use the compositor
make the scene with just the plane and the monkey - render

  • then composite it over the top of the sky

(if you post a pic it will be easier to see exactly what you want to do)

Put the monkey on a seperate layer from the plane. Now create two renderlayers, each one containing only the plane or the monkey. On the plane’s renderlayer you need to disable the “Sky” button. If you end up with a halo around your plane that is the same color as the sky (and you probably will) then make a duplicate copy of the scene, delete the the plane’s renderlayer from scene 1, the monkey’s renderlayer from scene two, enable the “Premul” button in scene two, and finally add a renderlayer to scene 1 which contains scene two’s renderlayer back into scene 1 via the node’s compositor. You do this by clicking on the little set of arrows on the bottom left corner of the renderlayer node in the nodes compositor which lets you choose which the renderlayer should take it’s info from. From there you can choose which renderlayer you want to use from scene two. This is how the devs were able to achieve such massively detailed renders in full-on high definition for Elephants Dream without crashing the hell out of Blender. Each scene is capable of using the maximum of system memory because they are rendered sequentially B4 the final composite takes place.
If you have any trouble with this technique P.M. me and I’ll show you how it’s done with a .blend and a bit more indepth information. Be sure not to delete the objects when you delete their renderlayers because raytracing does not span from one scene to the next.