In this tutorial I'll teach you how to make a light rig that will generate a nice, clean, soft overall light that's tinted green.
Paint Effects?



Okay - normally you don't use paint effects to light a scene, but here's an exception. We're going to use paint effects to generate a picture which will then be assigned to a sphere and sampled for Final Gather.

We're going to have to adjust the interface. Also, we're going to have to display the paint effects canvas.

Step one - On the view port menu bar, go to panels>panel>paint effects. [You must be registered and logged in to see this image.]

Step two - Still on the view port menu bar, go to paint>paint canvas. [You must be registered and logged in to see this image.]

Step three - Set the shelf to paint effects.
Painting



Select the tree brush on the shelf. [You must be registered and logged in to see this image.]

Basically what we're going to do is scribble all over the image until it's completely covered with trees. [You must be registered and logged in to see this image.]

We're going to erase one third of the top of the image. To get the Erase Paint Effects brush, open the visor. [You must be registered and logged in to see this image.]

Go to the folder Airbrush and select the erase brush. The erasing doesn't have to be even or 100% accurate.

Now we're going to add clouds to where we erased our background. Still in the visor, go to the clouds folder and select the Cumulus Cloud Brush. Draw a couple of clouds in the white area. [You must be registered and logged in to see this image.]

Now that we have our image, on the Paint Effects Canvas menu set, go to paint>save snapshot. Save the file on your hard-drive.
Step Back



I would like to step back here and explain how this same technique can be used to generate panoramic images that can be used in Mental Ray outside this tutorial.

By just changing a couple of brushes (instead of a tree brush use a building brush), you can completely change the image you are creating. There's a tutorial on my website that can explain how to take that image into the mentalrayIblShape and then use it to generate light. But in this tutorial we're using it to generate Final Gather.

Tutorial link]