Indirect lighting Blender Render

Support Lighting and Rendering
1

Hi everybody, I’m trying to understand how the Indirect Lighting settings under the World tab are supposed to work in Blender Render (NOT Cycles). I wasn’t able to find much on the manual; plus, the page

http://wiki.blender.org/index.php/Doc:2.6/Manual/Lighting/Indirect_Lighting

is void, which is different from non-existent in the sense that someone actually created it in the first place, but it contains no information. In addition to this, I found a few tutorials on the Internet which claim to describe indirect lighting, while in fact they focus on emissive materials; if you put a glowing sphere inside a Cornell Box it may look like indirect lighting but really it is not. So, I would like to know:

  1. Using Blender Render (NOT Cycles) is it possible to render the Cornell Box correctly?
  2. That is, can I illuminate the areas in shadow by simulating light scattering on other objects?
  3. How is the Indirect Lighting section under the World tab supposed to work? I tried to change the parameters and setting the Approximate Gather but I don’t get what I want, that is avoid pitch black (0, 0, 0) on shadowed surfaces.
  4. Can I bake a full render which makes use of indirect lighting to a texture?

Thank you for your help.

Dario

2

Blender internal is not a physical based render engine, so your answers is no, how ever you can achieve a decent approximation.

3

Indirect lighting is a way to fake/generate emissive GI. So you might be able to setup a cornell fake as well. It only has an effect if you raise the emit value for materials greater than 0.0. Approximate mode must be enabled as well. When I use the World features I ‘solo’ them one at a time if I know I am going to mix them together. Sometimes one will cancel the effect of the other. So you have to be careful when using AO, Indirect and Environment together.

Here is an example of just Indirect lighting up inside the shadow from a Sun lamp.


If you are a purist and find that you must calculate every light ray try using Cycles or Lux.