Hi everyone!
My name is Dennis and I just got my hands on the "VRay For Maya” demo! A friend asked if I could explain the basics, so here is a very simple tutorial.
First of all, if you haven't already then get "VRay For Maya” from ChaosGroup (
http://www.chaosgroup.com - you have to create an account). Then just install it; simple as that!
To load the plug-in, go to Window > Settings/Preferences > Plug-in Manager. Then scroll down until you find "vrayformaya” and check both Loaded and Auto Load and press "close” (Fig.01).

Fig. 01
When that is done, hit the render Settings button and choose VRay (Fig.02)!

Fig. 02
Ok, so now VRay is loaded, and we are ready to set some preferences. First, as this is a demo, the resolution is locked to 600*450 and it only supports 200 objects in the scene.
In this tutorial the settings in the "VRay Common” tab are not that relevant, so let's jump right to the "VRay” tab! To override Maya's environment check "Override Environment”, then I usually tint the blue color to a more white shade, but that's optional (Fig.03).

Fig. 03
Hit render. My scene looks like this (Fig.04)!

Fig. 04
Under the "Indirect Illumination”tab, check "On” to activate Global Illumination. Under the "Irradiance map” settings, you can choose from different quality settings; "high” is for production. Keep in mind that for test renders it might be better to lower the settings to medium or low, to save time (Fig.05)!

Fig. 05
New render (Fig.06)!

Fig. 06