store with irradiance map

[Nickh]

Hi,

I'm just doing some tests on an animation with the 'store with irradiance map ' option and its opened up a few, possibly funadamental, questions about vray setup...

Firstly, is this a good option to use?

I was under the impression that if I check this option, the solution will take longer, but render will be quicker. But this is not what I've just seen. Should this be the case?

And then in the rQMC sampler settings are these settings just for the solution process?

I've been lowing this to 0.001, turning global subdivs to 4.0 and then calculating the solution. But then if I've stored the vray lights in with the irrad map, is there any benefit of turning these down? or does it not work like that?

AA settings are QMC(1/5) Quadratic - which seem to be good, so am thinking its all in the subdivs now.

Any guidance or other tips greatly recieved. I'm just tying to get these animations as noise free as possible.




Cheers
Nick

[joconnell]

I presume that you mean with area shadows?

It's a good option speed wise as it means that the area shadows won't be raytraced every frame so it's quicker. It's bad in the sense that you'll have to up the subdivs of your light when making the irmap to get a quality equivalent to calculating shadows every frame but after that your area shadow is pulled from disk. Great for flythroughs and so on.

[Nickh]

I have one direct light with vray shadows (area is not turned on) and VRayLight planes.

So do you just turn up subdivs for the solution then?

Thanks
Nick

[joconnell]

Yeah you'll see yourself that if you have fine or sharp details in the shadow (such as a soft area light coming through slatted blinds) - it's just a case of turning up the subdivs of the light so that the detail gets captured in the shadow.

[Nickh]

sorry I don't think I'm making myself clear...

but then do you turn them down for the actual render, when your using your .vrmap? Or does it not work like this?

I guess I'm kind of asking if the rQMC sampler settings are only used at the solution stage?

[Neilg]

I dont really use it, but I thought sub'ds only came into play with area shadows.
if you dont have them on I'm not sure how much that will affect it, are you not able to do single frame low-res tests to see what works?

[Nickh]

subdivs come into play with VrayLights too.

I'm doing lots of tests, yes, just seeing if anyone could add any insight into things

[Neilg]

subdivs come into play with VrayLights too.

I was talking about vraylights, just ones that take up an area. Suppose I wasnt very clear, I dont use anything but vrays so Ive got a blinkered view on it.

[Nickh]

ahh got you. its ok to have a blinkered view about vraylights - they're pretty good.

[dynaman]

i can't say that my knowledge of this is conclusive, but i have noticed that using store with ir map works well for lights that only illuminate a small physical area of your scene (ceiling lights, illumination from a window, etc). but if you use this setting with, say, your sunlight which casts light over a large area you will get very noticeable blotches (not only in the shadows but everywhere). you might be able to fix this by really cranking up the subdivs, but my hunch is that you are better off not using this option for things like your sunlight, or a light plane creating illumination through a large atrium, etc.

[Nickh]

Thanks dynaman. That might explain the blotches I am seeing in this building with a large atrium being lit by a large exterior sunlight, and large internal vray lights. Maybe I won't use that option.