Moblur killing render times - Arrgg (VRay 2.4)

[Morne]

Hi all

I have a scene with some fountains that is killing my render times at 4K

I tried camera subdivs from 6 (default), all the way up to 2048!

I need the buckets to eat through there like it is nothing. I'm using 6 other nodes for DR so can't make use of the shade map. Although now that I think about it, maybe if I use just my pc and the shade map, it will be quicker than DR with 7 machines

Arrrg
Any other tips to speed this up? Maybe exclude the fountains from GI?

I'm using adaptive DMC at 2,50
an Hdri at 256 subs

Here's a screenshot of the sample rate showing my poor buckets sweating to try and get through the fountains:

[Morne]

Seems it is the refraction that is to blame, not the moblur. Investigating further...
(Weird because refraction is white and glossy is on 1 with 8 subs)

If I switch of "trace refraction" it east through it very quick. But looks bad

[vlado]

What if you set the trace refraction depth to 1 or 2 in the material? Also, have you considered 2D motion blur?

Best regards,
Vlado

[Morne]

depth of 1 doesnt seem to help much. (I've got moblur switched off now and the fountain part still takes forever)

[Morne]

ended up just switching off refraction. Will cheat something in post...

[joconnell]

Is it a still? Maybe do the water as a separate pass?

[Morne]

Hi John

Yes its a still. I ended up just switching off the refraction. A multimatte mask of the fountain on the RAWreflection in "screen" mode over the beauty looks great

Would be nice however to sort it, in case in future I may need a similar thing for animation...

[vlado]

Would be nice however to sort it, in case in future I may need a similar thing for animation...

Then it would be good to send us the scene for investigation.

Best regards,
Vlado

[Morbid Angel]

question would be how you generated the fountain, is it particles or what? Could be an issue with how those particles/mesh communicate with vray.

[Morne]

It's a superspray and the particles is spherical mesh with water shader. Well in this case my water shader si pretty close to glass. In the final just by looking at it, it isnt obvious what the difference with and without refraction is. For sure will revisit this at some point...

[Bruce Hart]

You haven't got blobmesh turned on have you? That's a real render time killer

[Morne]

You haven't got blobmesh turned on have you? That's a real render time killer

No I don't

But Chaos Support guys replied in an email that my max subs for AA of 50 is too high for the small particles. I have to either decrease that max value, or increase noise threshold. I'm happy however how it came out without refraction so will leave it like that for now...