RENDERED ARTIFACTS?

[restoeboemi]

[prey1979]

restoeboemi thanks my bad... thanks !

[GoncaloP]

Vrey high multipliers gives you very high render times...

Gonçalo

[restoeboemi]

so, the render time? 2 hours?

[prey1979]

the irradiance map took 12 hours 39 minutes the render itsself took 10mins at 2048x1556

[DP]

turn your h shpr subdivs down....try starting at 20 then increase by 10 each time if you dont like the look of the GI

h sphr subds is the tightness/accuracy of the GI, the interp samples is how smooth that GI is...i think they multiply so if you have yours set to 100 and 50 thats effectively 5000 samples, but you could lower the h sphr subds to say 50 and keep interp samples at 50 an that would only be 2500 samples, which would dramtically drop your render time...if im right...

[egz]

You can't multiply HSphere subdivs and Interp. samples to determine the total number of rays in each sample.

Intepolation samples are only used while rendering, not while calculating the irradiance map. There is a separate interpolation setting in the advanced settings rollout that lets you set the value used while rendering. The interpolation samples value determines how many GI samples will be used to calculate the final illumination at each pixel in the rendered image.

Basically HSphere subdivs works like this:
When VRay decides it wants a GI sample at a particular location it imagines a virtual hemisphere aligned to the surface normal around that location. It then shoots out a number of rays in quasi random (based on QMC algorithms) directions inside this hemisphere. These rays are then averaged to get the average illumination of that particular location. The location is added to the irradiance map, and VRay moves on to the next sample location.

To get the numbers of rays for each sample you can square the HSphere subdivs value. So for 1 subdiv, VRay only shoots a single ray at that point, in a random direction. This gets you really blotchy results since there is no averaging going on at all. I usually start at 20 or so and increase it to get a smooth solution. The list below shows how many rays will be in a GI sample with different HSphere subdivs. It might also help in estimating rendertimes. For instance going from 25 to 50 will make VRay trace 4 times as many rays per GI sample, and will probably make your GI calculation take 4 times as long. Going to 100 in the same case would give you 16x the calculation time.

HSphere subdivs: 1 = 1 ray
HSphere subdivs: 2 = 4 rays
HSphere subdivs: 3 = 9 rays
HSphere subdivs: 4 = 16 rays
HSphere subdivs: 5 = 25 rays
HSphere subdivs: 6 = 36 rays
HSphere subdivs: 7 = 49 rays
HSphere subdivs: 8 = 64 rays
HSphere subdivs: 9 = 81 rays
HSphere subdivs: 10 = 100 rays
HSphere subdivs: 15 = 225 rays
HSphere subdivs: 20 = 400 rays
HSphere subdivs: 25 = 625 rays
HSphere subdivs: 50 = 2500 rays
HSphere subdivs: 100 = 10000 rays

[egz]

I'd appreciate it if you could scale down the image or crop it to show the relevant parts. The width of 2048 is making the board hard to read (slalom scrolling).

[prey1979]

sorry egz my bad i apologise.
thanks for all your help

[egz]

hehe, no need to apologize. I was just getting a bit dizzy reading over my post

[DP]

thanks egz for that...i thought one had something to do with the other, but i didnt realise that it was quite like that ( i was just guessing )