Problems to separate renders for characters

hi, i have a lot of scenes in my cartoon and i need to separete the rendering process: i want to render character in a separate layer and the bg in another. i try a lot of time but my characters don’t take light, reflection and first of all shadows…
there is some tutorial or pipeline to help my in this adventure?

Well, it would help considerably if you could show us at least a screen shot, but here are a few general ideas.

First, I suggest that you start by working with multiple, linked, blend-files. Build your set (and its associated lights) in one of them. Build props in another. Characters in another. This will allow you to reference these scene elements in many files while defining them in only one place.

The next thing to consider, this time for each shot, is where and how you are going to light your background (which I recommend doing with lights that are layer-specific only to that background …), and then, separately, how you are going to attractively light your characters. I prefer to treat these problems separately, even if two lamps with the same settings are at (almost) the same place in 3D space. I use layer lights again.

Now for shadows. Here, RenderLayers can be very useful, because when the character interacts with any of his surroundings, your primary visual cue … the linch-pin of the entire 3D illusion … is the shadows that the object casts upon the surroundings. You need to be able to extract that shadow information in isolation so that you can at a later time composite the finished shot together.

This would be an excellent time to bone-up on these things:

  • RenderLayers
  • The RenderLayer compositing node.
  • The “MultiLayer EXR” output file format, and the Image input compositing node.
  • Any book or tutorial you can possibly lay your hands on the subject of Blender compositing.

Here’s food for thought: the “final” image that you “finally” see is almost never what any particular rendering operation “came up with.” Rendering was, instead, used to generate raw inputs for subsequent (and sometimes, extensive) manipulation by compositing nodes … which create a “digital production line” of sorts that leads to the final image as its output.

and if “I already knew that, you doofus” … i humbly beg your forgiveness!

hi, thanks
i use render layers and multilayer exr and merge them with z combine. the problem now is that character layer are in render more brighter: when i render character with all scene luminance are ok but if i move charcters and all lights in another layer they become more brighter…why this?