Sub-Div Shoot


(DAK) #1

Subdive Shoot element & subdiv shoot patch seem to be 2 buttons that tutorials claim you SHOULD push in order to get better radiosity samples. However, I tend to not notice any difference in my radiosity scenes. What exactly are these buttons meant to do?
also, if I set max iterations to 0, I still get blender stoping the radiosity solution sometimes after a while. Is there a sensor that stops blender if it sences the scene is now too bright?


(DAK) #2

I guess no one realy knows these things. Does anyone at least know why sometimes radiosity light seems to shoot right through walls sometimes and keep on bouncing?


(RipSting) #3

The subdivide & shoot buttons are the manual way of doing radiosity. Otherwise, just pressing the “GO” button does the same thing many many times. Blender doesn’t stop because it sences that the scene is too bright. No, it goes until it’s emitted enough light so that all patches interact with all elements within their range. The patch size is determined by the “Hemires” property. So turning up Hemires will be more accurate.

If you’re unhappy with the brighness or contrast of the scene after the radiosity has finished calculating, mess around with the Mult and Gamma buttons. Also, “Face Filter” and “Element Filter” are good for removing artifacts that can show up. Just remember there’s tooltip text for just about every button.

Light may go through polygons if their normals aren’t pointing in the correct direction. Try recalculating the normals by entering edit mode on the wall, selecting all the verts, and press Alt-N.


(DAK) #4

Ok thankyou ripstring. I will try playing around with the normals more. I had assumed since planes were double sided by default that this should not happen. I guess I am still a blender newbie.
I will turn up Hemires and see what happens. And I guess I should keep the shoot’s toggled on as well.
Maybe someday I’ll figure out what the distance between the 2 colored squares are.