Heavy use of VrayLightMat

Hi all,

I think I might have seen this talked about before, but I can’t find anything on the search.

I am lighting the inside of an underground walkway. The lighting is from two sources, strip lights behind cladding on the walls to act as uplighters, and a central strip light running down the middle of the tube.

When I have used vray lighting in the past, I have ended up with over 100+ lights and the render times die. I am wondering if I can get away with using only geometry with lightmat to light the whole scene. Are there any problems with this method, and any particular settings that I can concerntrate on to get the quality of light.

I want to use real world camera settings, so I imagine Ill need very high values for the lightmats!

Thanks

I’ve been getting satisfying results using VraylightMat recently. Here’s a list of things I would advise:
-try and avoid using small objects as light sources
-to create specular highlight, I use Omni lights if diffuse turned off
- I don’t use real world cameras, but my values range from 0.5 to 6-7 for the vray light mat.
VraylightMat isn’t perfect by any means but for me it works really well in the sense that I can have billions of light sources and it doesn’t affect the render time on bit. (or doesn’t seem to anyway).
I can’t think of anything else for now…

Thanks Fabriceb,

Some good points there. Im expecting values of at least 1500+ with an exposed camera. I do wonder whether the value will need to be changed depending on the size of the strip light. for example, I make a lightmat at 1000, and put it on a tube 1m long, and works nice, then put same mat on a 10m tube, will the light given off be the same, or will different sized objects need different values for same power? Ill have to test!

Thanks

I’ve noticed an increased amount of noise and GI artifacts when using the Vray light material. Anyone else?

There is a formula to find the “proper” value for a given surface area. You can use the Measure utility to find the surface area.

http://www.chaosgroup.com/forums/vbulletin/showthread.php?t=34536&highlight=surface+area