gi disabled

[oren]

something i must to figure out

Corona - interior - gi disabled... sky light in environment - the light still come inside the room even with no gi

Vray - interior - gi disabled... sky light in environment - the light is not able to go into the interior...

how and why its like that? no gi in both the engine... not interior light and no portals!

thanks

[Morne]

This was the reply in your other thread, which is probably the same answer here

My wild guess is that you are not using domelight in V-Ray.

Corona does image based lighting from environment by default where as V-Ray defaults to just naive sampling of environment using random GI rays. In case I am right, then just add Dome Light to your scene and instance environment map into it.

[vlado]

Corona creates an internal dome light for the environment. To match both results you will need to create a V-Ray dome light and put the environment map texture in it.

Best regards,
Vlado

[oren]

ok vlado but with dome light and sky light inside and no gi its like that (progressive)

even for long time... all this ugly holes

can i fix it?

[vlado]

There are several ways to improve it:
a) increase progressive sampler min. subdivs;
b) increase min. shading rate;
c) enable GI.
d) simply let the render to run longer - the black areas will vansih eventually.

There are also other methods, but I'm not really sure you need to go into such details. Why do you need to render without GI anyways?

Best regards,
Vlado

[oren]

hello vlado
i dont really need render without gi, i just want to check how the light effected the room and how fast it can clean the noise...
i found that if i want fast clean method then i need to put Portal light outside the opening in almost all interiors.... unlike other engine that portal can create more noise... is portals in vray is so much different from other engines?

did you recommend to use portals in every interior project? or the portals thing is not modern option and will be vanish from vray in future ?

sorry for my curiosity

[vlado]

Every engine implements portals in different ways; for some engines, portals are not well implemented and don't really have much of an effect, but for V-Ray they do - at least for the moment.

With that said, we are working on ways to improve light sampling that will hopefully reduce the need to use portals in the future.

Best regards,
Vlado

[oren]

i got it!
thanks....
ipr ipr where are you?? just kidding

[LudvikKoutny]

When we are at it I would again like to take a chance to push through my idea to have environment sampled as direct light by default.

Not only is it easier to setup and keeps scene a bit cleaner (and avoids confusions like this one), but it could also resolve that dreadful matte object bug, where secondary rays that hit parts of matte object outside of camera frustum ignore dome light, and tend to hit environment backplate mapped in screen space, resulting in ghosting of backplate through scene meshes and requiring me to further enable global illumination and reflection/refraction environment override, and instance my environment map in those slots as well. As a result, I have now environment map instanced in 4 different places. Aside from that, it also adds lots of noise if the HDRI map features some hotspots in the direction of those rays that pass through that "hole".

[vlado]

Yes, yes, it's on the "to do" list... will get to it.

Best regards,
Vlado