Light Beams and Vray Lights ?

[bernhard]

Maya 2011, Linux Fedora: Vray 2.0beta

I just made a quick test to achieve light beams in combination with vrayenvfog.
It works fine when using a Maya Spotlight, but I wonder why it is actually not working the same way when using any kind of Vray Light ?

Like vray rectangular or vray spherical ?

[aweidenhammer]

Well, it would depend on the size and intensity of your vray lights. Since they are area lights, they throw illumination in many directions from many sampled points on the surface of the light. The character of the volume light effect will vary enormously based on the size of the light. If you use a maya light, then all light is coming from a single point, and the "beams" will appear much more defined. If you scale your vray lights down much smaller (and increase intensity) you will probably approach the same look as a maya light.

a large vray rect light would create a generalized hazy glow in the envFog. A sphere light will always be a radial hazy glow, since by design, it throws light in all directions.

Andrew

[bernhard]

Hi Andrew,

thx for your reply, I really appreciate that.
Yeah.. that's the thing... I used a VrayRectLight and changed the size to 0.01 and cranked up the intensity to crazy values.

But what ever I do with the vray lights (rect/sphere), changing size and intensity - there are no light beams.
It's really interesting, because in the same scene.. I just turn on a Maya Spot Light and peng - light beams are there.

So I was wondering, why I never ever could achieve the same beams with a vray light.

[super gnu]

by default the vray light throws light out in a 180 degree arc from the surface, in the same way as a spotlight with the cone set to 180 degrees. i dont know about maya, but in max there is now a "directional" parameter for the vraylight allowing you to focus it into a parrallel beam similar to a direct light. then its much easier to get a volumetric ray.

[LarsSonparsson]

And fyi. Directional option is new feature in vray 2. Not found in earlier versions.

[bernhard]

thx for teh info, sounds really good for the max version. Well... I am on Linux Fedora on Maya 2011 and vray2.0beta - but can't find that feature for the vray lights - maybe some additional hidden vray attributes ? Would be really fantastic to have that option - many thx for posting !