Can you tell that there is more light emanating into the shadows when there are some diffuse bounces? This is something to play with on a per scene basis, but my recommendation is that you set it to 10 for most of your work, unless your needs deem otherwise. Alright, so that was pretty easy huh?Let's now take a look at some of the other wonderful thing Mental Ray has to offer you.
Open your Material Editor. In the first blank slot, hit the Standard button so we can change the type of material. Now you see all those yellow dots? Those are material types specific to Mental Ray. I want you to go ahead and double-click on the first one, Arch & Design (mi) (Fig.17).
Now that we have changed the type of material, open the Select a Template rollout and look at all the prebuilt materials you have to pick from! In Fig.18 you'll see that I applied a basic template to each of my objects. No changes were made to the materials themselves; they are completely set to their default settings.
Should give you something to play with!
The last thing I want to show up here in this introduction to Mental Ray is something you might need to do to make your renderings a little cleaner. What I mean by this is if you look at the above render, you will notice the pixels running along the top edge of the wall. See how jagged that looks?
Let's fix it! Open the Render Scene Dialog and go to the Renderer tab. In here make the following changes (Fig.19).
Now we're telling Mental Ray to increase the amount of pixels used to generate each image. Here's the result (Fig.20).
A lot cleaner!
Remember our Draft setting within Final Gather? Here is what this render looks like with it set to
The biggest difference is the render times, so be careful with this if you are rendering animations!
Do you notice the difference? Me neither, but the render time went from 1 minute to 4!
What's the point? Well, unless you're doing high end architectural renderings, leave your Final Gather set to Draft.
Okay, so you now hopefully know how to set Mental Ray as your renderer as well as how to set up your lighting. You also should have a good frame of reference to begin playing around with your Mental Ray materials.