Refraction environment override

[fAEkE]

I have always thought that the point of refr override was to split Refr environment from Refl environment. But after som testing at work I saw that it works in another way..

It seems to take over refractions from everything in the scene for some reason. Take a look at the image. The sphere is fully refractive and should refract the plane that is behind it, but it doesnät, it refracts the Red color that I have set in the Refraction environment override. Even more strange, the reflective plane behind it reflects the sphere as red, even tho it's fully refractive and has a diffuse color of green. It's like the only thing "Refraction environment override" does is to colorize everything that is refractive in the scene.... why does it work this way?

[fAEkE]

Anyone?...

[windowlicker]

I see nothing wrong in my tests. Made a scene with a white Vray plane, a black box, a perfectly reflective material and a perfectly refractive material (without reflection). In the first image an HDRI is used for lighting and environment. In the second, another HDRI is used as a refractive override.
you can clearly see how the refracted environment is changed in the refractive sphere (centre) which is also reflected in the reflective sphere. Lighting and direct reflections are unchanged.

Correct, no?

[fAEkE]

Hmm, ye thats correct.. we have my problem on all our pcs with vray2.0.. strange

[vlado]

Once a ray goes through refractions, it will always use the refraction environment override (as opposed to just looking at the type of the last ray). This explains your results.

Best regards,
Vlado

[fAEkE]

I don't understand. Why don't "my" ball refract the plane behind it?

[vlado]

I don't understand. Why don't "my" ball refract the plane behind it?

It does. However the plane is reflective - so any rays that go through the ball, reflect off the plane and hit the environment, get shaded by the refraction environment color - which is red in your case.

Best regards,
Vlado

[fAEkE]

I see. Why was it made that way? It should refract the plane as the plane is viewed, shouldn't it?

[windowlicker]

It overrides any directly refracted environment. If the object refracts a reflection, then the override won't work, since what is refracted is the actual reflection... which is not overridden.

If you want it differently (I think I see where you wanna go with this), I'd render two different scenes with different env maps, then mask/merge them correctly in post.

[fAEkE]

I think you all have missunderstood me, what you said first windowlicker is exactly what I want to happen, but it doesn't work. Look at my render. If I put IOR on the sphere to 1.01 it should only refract the plane, but instead it refracts the environment behind the plane....

[windowlicker]

Heh yeah, I might have. But I can't recreate the situation you have there, no matter how hard I try. Can you post the scene? It looks just as if you've set the fog color to red.

[dlparisi]

I think you all have missunderstood me, what you said first windowlicker is exactly what I want to happen, but it doesn't work. Look at my render. If I put IOR on the sphere to 1.01 it should only refract the plane, but instead it refracts the environment behind the plane....

You can put a map in the plane material's "Environment" slot to override the reflected rays seen in the sphere.

[fAEkE]

www.cgpro.se/Tillfallig/Test.rar

Just put one of your own HDRIs in the environment refl slot and you will see what I mean.

[dlparisi]

Do you mean the "Refraction Environment Override"?

[fAEkE]

The refr override is set to red. Put a random hdri in the refl override and you will see that the sphere refracts the red environment, behind the plane.