VRay 3: Understanding the sun

[igendreau]

So I'm taking a vray tutorial largely done in 3DSMax, where they keep inserting a sun and placing it wherever they want. I'm demoing the new VRay for Sketchup 3, and am having a bit of an issue wrapping my head around how the sun works. Hoping someone can either explain, or point me in the right direction...

I've got "SunLight" it my Light List in the V-Ray Asset Editor
I've got GI (skylight) and Background in my Environment rollout
I've got my Shadows toolbar with Time and Date settings

1. If I turn all 3 off I get pitch black
2. If I turn on SunLight, I get light
3. If I turn off SunLight, and turn on GI, I get different light

So which one is actually the sun, or is it a combination of the two? And does changing the Time/Date in shadows affect the light from the "SunLight" light, or the GI light?

Sorry, I'm a newbie. Thanks for the help.

[tedvitale]

No worries, newbies are welcome too!

So, In SketchUp, there is always a Sun Light in the scene. Because you can't delete the sun in SketchUp, we don't allow you to delete the Sun Light In V-Ray.

Shadow settings can be controlled by adjusting the time and day in SketchUp, these will effect the sun light location in V-Ray. Turning Shadows off and on in SketchUp will have no effect on the sun being off and on because the shadows on in SketchUp cause heavy lag in large scenes.

Now, the Sun Light in V-Ray is linked to your environment settings, so like you mentioned, to turn off everything you have to turn your Sun light off, your GI and Your background off. Your GI (indirect or global illumination) is the secondary light from the sun, So the sun light is your direct light source and your GI is your secondary global lighting source linked to the sun. Your background provides reflections and is also linked to the sun light. Now you can turn each individual part on or off manually to get different results, but they all work togeather as the environment.

I think that helps? I may have made more confusion by trying to explain it in a single paragraph. V-Ray for SketchUp has a lot of features Max has, and shares similar workflows but sometimes things are not 1 to 1 because SketchUp is such a different modeling application.