real sun/skylight

[Da_elf]

not sure but maybe he meant that if you had caustics in the scene that you couldnt see the reflection of them. like caustics on the floor but looking at the floor in a reflection there wouldnt be any on it. but im not too sure that what he meant

[vlado]

not sure but maybe he meant that if you had caustics in the scene that you couldnt see the reflection of them. like caustics on the floor but looking at the floor in a reflection there wouldnt be any on it.

Yes, this is what I meant. Caustics from small light sources, or caustics from nearly parallel sunlight...

Best regards,
Vlado

[deneb26]

it's a pitty, but that's true,

i tested it and this is what came out



*sigh* this is really frustrating.

greez
ale

[Gijs]

Thanks for posting. Will you post this to Maxwell forum as well? I am interested to see their reaction, although I doubt that they are not aware of this limitation.

Vlado, what confuses me a bit is the fact that you mention 'small' lightsources. Do you mean that large ones will be visible in reflection?

[vlado]

The "impossible" situation involves point light sources or perfectly parallel ones, perfect mirrors/glass and a perfect pinhole camera. In that case, it is impossible to compute the GI solution in an unbiased way.

As you deviate from the "perfect" conditions, the missing parts will gradually appear, more noisy at first, but getting better as the light source gets bigger, or the mirror/glass - more glossy, or the camera - with a wider aperture. However, even situations close to an "impossible" one are also quite impossible to compute in a reasonable time.

Such situations are actually quite common - for example, imagine a room lit by sunlight through a glass window. Sunlight is very nearly parallel. Glass typically has very little glossiness. If you put a mirror in the room, you get a situation close to an "impossible" one - you will not see the sunlight in the mirror at all (or it will be very noisy). If you look into the room from the outside through the window, it will appear dark.

Another situation is a waterglass lit by a small light source or sunlight - the part of the glass that rests on the ground will be dark - you will not be able to see the caustics beneath it or any other caustics in the reflections on the glass.

Best regards,
Vlado

[Mark David]

So, at the end of the story...

VRAY RULEZ


best regards

Mark

[Frances]

The "impossible" situation involves point light sources or perfectly parallel ones, perfect mirrors/glass and a perfect pinhole camera. In that case, it is impossible to compute the GI solution in an unbiased way.

Hi Vlado,

To clarify, Maxwell doesn't have any of those things. The caustic eventually will be visible - if you wait long enough.

Actually, I'm not sure what the Physical Sky does.

[vlado]

To clarify, Maxwell doesn't have any of those things. The caustic eventually will be visible - if you wait long enough.

Indeed, but you can get very close to them, and in most cases you will need to do that. The closer you get, the more "long enough" will mean "infinitely long"...

Best regards,
Vlado

[RErender]

It's been my experience that "infinitely long" renders are really bad when doing animations

[percydaman]

It's been my experience that "infinitely long" renders are really bad when doing animations

lmao... smarta$$...

[tom schuelke]

Ah..

nice to see, that our heros havn´t been toped by others so far.

but, i would like to mix al the good stuff together, some things from brazil, the speed from vray, the great setupspeed from maxwell....

i would like to know what will come there for more.

..... waiting for the standalone



tom

[Syclone1]

It's been my experience that "infinitely long" renders are really bad when doing animations

lmao... smarta$$...

your just upset cause he beat you to the punch Percy

-dave

[percydaman]

as a resident smart a$$, I cant disagree with that statement...

[Syclone1]

as a resident smart a$$, I cant disagree with that statement...

lmao

-dave

[tom schuelke]

Hi over at the Maxwell forum,

Oscar Maxwell has answered to the thougts of Vlado.

Well Maxwell will not use pinhole cams, and also pointsource lights will not be involved, only realworld things,

But !!!

someone has rendered a scene with caustix and reflexions, and also reflected caustix, and they appear absolutely as vlado told.

very very grainy and seem to render very long time.

Still seems to be no perfect way to acheave all.

Tom