hemi-sampled glossy speculars/soft reflections

[Ruairi]

Hey, I used to test Arnold, and one of the most amazing things about it was how soft reflections were calculated, which used the same technique as it used for skylights, which was some kind of hemi-sampling thingy. I don't remotely pretend to understand it, but it worked really well, and was incredibly fast, (literally, it made little difference to the render times depending somewhat on the scene setup...)

I've noticed the same is most definitely not the case at present in Vray. Just wondering if this is something that is likely to be addressed...?

[vlado]

This is because Arnold uses brute-force methods for both GI and glossy reflections, and they run at very similar speeds.

VRay can do this also, if you are using QMC GI together with glossy reflections. In that case, the overhead of adding glossy reflections can be quite small. There is some difference though, which may be a thing to optimize...

Best regards,
Vlado

[cpnichols]

In addition to this... Since Vray gets a lot of its speed/quality from its irradiance mapping method, Vlado added a method of doing interpolated glossiness which runs at the same time that the irradiance mapping does. It is a simple checkbox in the material editor. This is in fact really cleaver... Glossy reflection, blurry refraction, and soft shadows all can be optimatized during the irradiance map calc.

Basically this means that you can also get the option of doing fast glossiness effects by doing them with the irradiance map calc.

Personally I don't think the results are always as good as the brute force method when it comes to glossy reflections. And I am pretty sure that Arnold is much faster (if not the fastest) at brute force hemispheric raytracing.