Is there a bug with the radiosity in 2.32 because i cant get it to work. Maybe its just my stupidity, could someone please tell me how to do a basic render of a cube using radiosity to light the scene. Any help is appreciated as always.


radiosity calculated at render time?

if so, each material in the calculation needs to have the radio button pressed, and the radio button needs to be pressed in the display buttons

if you meant precalculated radiosity, ask and I (or someone not sleeping) will attempt to help you

I blend part-time so im sorta old and new to blender at the same time %| Could you explain what pre-calculated radiosity is. Im at work right now but I’ll check back when I’m at home. My real problem is that once I get everything all setup and I render the scene blender stalls out or crashes horribly, depending on what OS im using at the time… I made sure i had the scene set up correctly. Maybe im just doing somthing wrong. When i click the GO button in the radiosity menu it stats to light up the scene, do I then render the scene or is there somthing i have to do before or is there another way to render… I forgot alot since last i used blender. Thx for the help.


the big GO button is for calculating before rendering, it is the old way

once calculated click on add new meshes (replace meshes if you save a lot, you can’t run the calculation again if you replace them though) and it will create a new mesh (multiple if there are enough faces or verts) of the result, and give the materials applied to the mesh (there better not be more than 16 materials’, counting duplicates in different objects) the “Vcol light” flags a value of true

the other way is, you set things up, you press the radio flag in the material buttons for each material in the calculation, you subdivide the mesh enough (some), and press the radio button in the render buttons, and render. This produces slightly different results because of no subdivision, and because the radiosity solution seems to be added after textures, as opposed to before as light would, this can result in washed-out textures in a scene lit primarily with radiosity.

Ok I did just as you said and all i got was a black screen that never rendered. Do you know where i could get an example of a properly set up scene so that i could figure out what im doing wrong? Thx for any help.


RADIO RENDER Without preprocessing needed (New radiositymethod)

Examples (439 KB) at:


If you click on the Blender console window whilst rendering, you will be able to see the progress of the render passes for radiosity calculations. You will only get a black screen until it solves. The default count is 250.