Rendering Layer Dilemma...
 

Hi people,

I have a scene to render and i want to render objects in different passes... now, i've put groups of objects into render layers and i want to render them, the only thing is, because of the materials that i'm using they come out really dark unless all objects are rendered together

mainly because i have very dark materials with a very high reflectivity (i think...)

is there a way to render an object to a layer with all the reflections and shadows without rendering the other objects in it?



example, say i have two spheres in the scene and each one reflects off each other and casts shadows on each other

i want two layers, one for each sphere, and i want the render to have all the reflections and shadows that it would normally have if the sphere was actually in the scene... (i only want one of those spheres rendered)

Any object that will be reflected needs to be in your render layer.
After that its just a simple case of going into your reflected object or objects shape nodes and turning off primary visibility on them for that layer.

These are called layer overides, to make a value overidden in a specific render layer just make sure you are in the render layer you want, right click on the attribute and click create layer override.

When you render now the objects which have primary visability overriden will not appear in the render but they will be reflected.
If you want to do a reflection pass which you can then appy to your other layers in compositing just assign a highly reflective matterial or a use background shader to get the correct output (no diffuse or specular color should be visible for this result to be correct).

I just completed a 2-part Render Layers & Material Overides 101 video tutorial series that David will be releasing ASAP, so you might want to watch for that to get a better understanding of the whole process:)