I decided to make my own Cornell Box to play around with some of the features of Mental Ray, Final Gather to be more precise. Below is a thumbnail of my first attempt. Click on it to see a larger (640x480) version.
Render Time: ~ 4 min. AMD Duron, 500MB RAM.
Notice the interflection of colour from the red wall onto the back wall and ceiling, and more noticably the green bleeding onto the box in the forground. Note that the colour of the entire box is the same as the floor, back wall and ceiling.
Below is my second attempt. This time using a "glass" sphere to test for caustics. Unfortunately, I must be doing something wrong since the glass doesn't seem to collect light at the bottom. And still, the "chrome" sphere is pooling light where it shouldn't. Live and learn. I also bumped the number of photons from 1000 to 5000. This seems to have cleared up some of the patchy discolouration of the walls etc. It also bumped up the render time.
one strange effect is the gathering of light at the bottom of the sphere. This looks like a caustic effect, but shouldn't be.
