vray- prepass-GI

[amal_auc]

Hi guys

Am trying to get used to the settings of vray.
I see under the GI when i change the settings and render, i get the prepass 1 of 3 or 4 what exactly is the prepass doing and does ther prepass thing have different settings for different scenes or does it have a standard for all scenes.

thx :P
amal

[J_Bug]

The Prepass is basically interpolated Global Illumination (GI) or a means to avoid the time consuming task of Direct Computation (Checking the bouncing/ reflecting/ refracting rays of every single pixel, divided into samples, for an image). It's a quicker, smarter, more controllable method than using Brute Force or Direct Computation. In VRay, the Prepasses can consist of quite a few methods (Irradiance Map, Global Photon Map, Lightmap or even Interpolation for blurry effects like glossy reflections). The parameters can be set drastically different for the limitless potential of a 3D environment but I would say that the highest level of differentiation is between indoor and outdoor scenes. There are also setting which are better suited for detailed studio setups along with many more possibilities. It's really quite a bit to learn and a good start is vray.info

--Jon