Vray Light vs Vray Light Material

[dominiquelaksmana]

hi good fellas,

gotta ask you this question, because i practically can't ask anyone else in my company since i am the only one doing this visualization, although may seem stupid, but bear with me on this one.

Vray Light and VrayLight material are different one and another right?

i guess when you tick the "store with irradiance map" vray light will behave like vraylightmaterial correct?

i mean, with vray light, no matter how low my settings are,
i can still get good result with it. but not with vraylight material. even sometimes with high settings and hours of rendering, i still am getting those blotch and splotch. is it true that vray light material works similarly with vray sky and environment light ?
i am working in an interior design company and they like to do this "cove lighting" on the ceiling and sometimes curvy and all. if i just apply vray light material and render it, even with high settings, includes bringing the samples in rQMC up to 70 and multiplier to 4, still, i am getting these blotchines. sometimes i have to do some heavy "array" for vray light to get descent result, because practicaly we can't bend vray light.

we can make vray light behave like vray light material.
the big question is : can we do the opposite?
can we change the vray light material to behave like vray light ?/

hopefully i get good answer from you great ppl out there,
well, you can mock me also if this question really is stupid.

thanks alot!

[studioDIM]

i *think* you could try and use a light set as skylight portal to cover the hole (and the whole ) of the dome (ie. the base of it, where it meets with the walls), to tell the sampler to concentrate on the area.
That definitely works well in PPT mode (of course, make sure you have no BG), and might work well with other GI methods, but i am NOT sure it does.
May be worth a try though.

The reason is the VRay light has a direct contribution, and a definite source, whereas the light material is only indirect, so its sampling it's left to the GI sampler which has to try and "find" it without any help.
Setting the light to skylight portal will tell VRay where to look for a source of light (it won't find any BG, of course, but magically discover there's a light material behind it...)

Do a search, there's a thread with some more info from Vlado on it, along with -if i recall correctly- a couple of quick benchmarks.

Lele

[dominiquelaksmana]

will do lele, thanks alot

[tricky]

We've had similar issues with cove lighting. It would be great to have a bendy vray light object rather than relying on vraylightmaterials which require much higher irmap settings.

Vlado - is this a possible future option?

[sv]

I also struggle with this - recently had to do a cove lighting rig on an auditorium which was soooooo easy using the light material, but it just ruined the rendering, so i had to create and copy about 50 really thin VrayLights around the cove lighting bit and only use these.

So lele, are you suggesting we could simply use the VrayLightMaterial, but position a VrayLight as a skylight, (or perhaps a few) over the VrayLightMateiral and it should work out better?

PPT - not an option as it's an animation, and, as always, render times need to be really low - like they are without the VrayLightMaterial.

[RErender]

Vlado has said he is working on a "object light" so you will be able to turn any mesh into a vrayligt.

[Paul Oblomov]

Well, for those, who already did smth with a VRaylight mtl, but now it looks baad - use DE. Of course it won't be fast, but at least you can get the same quality as with VRaylight.

[studioDIM]

rendertime: 1:14" with a big arealight set as skylight portal, store with IRmap (medium, customized to -6/0).

Rendertime: 47" without portal, same IRmap settings.


While the rendertime grows (almost double), the quality of the shadows is really good, along with splotchiness disappearing entirely (may need to save the image and zoom in a bit on the torus knot to see it).

this is the setup:


Hope this clarifies it a bit...

Lele