Sun GI

[ValeroStudio]

One question I always had was when you use the Vray sun, where does the GI come from? If you look at the settings it’s only the background that has the Vray sky in the map slot. When you use an HDRI along with the sun, does the G.I. only come from the dome light or is it a combination of the Vray sky and the dome light?

[konstantin_chaos]

Hi Matthew,

For all Environment overrides which are disabled the Background texture is used - Reflect, Refract, GI, etc.
If you add a Dome light in the project it by default overrides the Environment.
Note that when the Dome shape is set to Hemisphere, the bottom halve is missing and you'll see the environment there.
Also if the Dome is made invisible, the background/environment will be seen by camera and refraction rays.
When Affect Reflections is disabled in the Dome, the Reflection Environment will be reflected instead.

In no situation are the GI affects of the Environment and the Dome combined.

I created the following scheme that might help you understand the environment hierarchy in V-Ray:

To get it you should imagine that the ray you're interested in is starting in the middle and goes out.
When it hits a circle with the same as its color it samples it unless the option I've specified is disabled.
Note that the inner 3 circles stand for the Dome light, the 3 outer ones are the environment overrides and the last one is the Background environment.

Hope that clarifies things to some extent,
Konstantin

[ValeroStudio]

This is incredibly informative and I really appreciate the time you took in creating that graphic, so so helpful!. Thank you Konstantin.