Lighting & Rendering Setup

I’ve spent the past few days cleaning up the geometry a bit, but mostly studying Mental Ray to determine the best render settings for the short video I’ll be creating for the demo of this project. I learned a lot in the process, and found this site, TOI-Pedia, to be particularly helpful. I realized that I was playing around with settings that I didn’t know exactly what they did, and was wasting a lot of time in the process. They provide a really helpful explanation of both Global Illumination and Final Gather, both of which are methods of calculating indirect illumination. I found that though you might normally use either one or the other, there are situations in which using both is helpful, such as in lighting Bag End. It’s a mostly-closed interior: light can only enter through the front windows and the front door, if it is open. So it was frustrating when trying to use Final Gather and Image-Based Lighting (lighting based off of illumination from the environment), because I had no other lights to illuminate this tight-spaced interior.

So I returned to my original lighting setup, bumped up my photon count for each light to at least 15000 (for Global Illumination), and configured Final Gather to include 2 secondary bounces. This was important because I needed the additional illumination in the scene, but also so it would create a softer image. For those of you rendering with Final Gather in Mental Ray, be sure to make use of the Point Interpolation attribute in your FG settings. This is what TOI-Pedia has to say about Point Interpolation:

“Mental Ray can do some interpolation to achieve nice and smooth results without too much (expensive) Final Gather calculations. Increase this number to smoothen your render. It’s not as accurate as increasing your Accuracy, but much, much faster. This setting determines the number of Final Gather points that should be considered for interpolation.”

So using Final Gather and Global Illumination really also becomes a matter of time. Some settings, like Point Interpolation can be used to save time when set up properly, while others, like FG’s Point Density, do a lot to improve the quality of your image, but are “expensive”, requiring much more time. Secondary Diffuse Bounces are another of these expensive settings, increasing render time exponentially as the value increases.

Anyway, this is what I came up with, following a 2.75 hr render (overnight) at 1280×720. I think it’s looking nice, though I’ll be trying to optimize since I have to do a few hundred frames for my animated camera move the demo is calling for.