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View Full Version : Vray for Maya directional light?

Hakushinkan
06-08-2012, 11:55 PM
Hey all,

I'm using V-Ray to render a scene, and I'm trying to use a directional light as a sun.

I'm making a basic Maya directional light, turn on ray-trade shadows, I add the V-Ray attributes and I hit render (GI on). I get a nice "light stain" with a shadow and everything, but it seems GI does nothing. Everything other than that stays either black or very dark, as if the GI effect is very weak.

In Max there's a way to turn a V-Ray square light into a directional light, but I couldn't find how to do that in Maya.

Is there anything I'm missing here?
Schempp
06-09-2012, 07:38 AM
When you say gi on, have u switched it on in the render globals AND choosen a color or a texture for the gi?otherwise u wont get much.
Hakushinkan
06-09-2012, 08:31 AM
I turned it on in the V-Ray Indirect Illumination tab in the render settings.

I'm not sure though what you mean about choosing a color for it...
bigbossfr
06-09-2012, 02:23 PM
Enable envirronment override in render global.
Choose a GI color (default is blue).

I turned it on in the V-Ray Indirect Illumination tab in the render settings.

I'm not sure though what you mean about choosing a color for it...
Hakushinkan
06-09-2012, 03:27 PM
Oh, yes environment overrides are turned on and I didn't change the color. But even with changing it, there's little difference.

Maya's directional light does provide SOME GI but the room stays very dark.

The only way for me to get any GI going is by making all the materials fully white. The scene is supposed to be pretty dark, but I do need some GI going. The directional light hits a wooden floor that's kinda dark, but I expected it to send out a stronger bounce light... which it doesn't.

Is it a problem with the scene materials, or do directional lights produce weaker GI?
Hakushinkan
06-09-2012, 07:59 PM
I just realized something - it was all about camera exposure.
I never thought different exposures in VRay would get my different results in regards to GI. When I increased exposure on the camera, it was more sensitive to GI than when it was lower, in relation to the amount of light required to "burn" the place on the ground where the light hit.

Well, that was some good schooling. :)

I have another question and I don't want to open a new thread for it.

I'm trying to create clouds, the method I was thinking of is basically creating planes that have textures of clouds on them, and have them floating around far from the camera.
I thought I'd just get a material, give it the texture, make it self illuminated and give it an alpha to remove everything that's not needed, and I'd have a cloud.

Problem is that I can't get my object to be self-illuminated.
VRay renders anything I know of as self-illuminated - as a black object.
The only thing I could bring to being self-illuminated is a light material, and that one did not take an alpha well, I get my whole plane white.

I tried a surface shader, a lambert with incandescence, tried a vray material with self illumination all the way up... Everything gives back either a black cloud with the plane still slightly visible, or just a black plane. Light material (with high enough intensity) gives out a white plane.

Is there no way to do a self illuminated alpha-driven object in VRay?
Schempp
06-10-2012, 08:29 AM
what version of vray are you using? in 2.0 the self-illumination on the material works correct?
Hakushinkan
06-10-2012, 08:31 AM
I'm using 2.0.

I found that if I turn off exposure control on the physical camera, it works, but I need it on... so I really have no idea what to do next other than add clouds in post production =\