HSph subdivisions per object

[3DMK]

Hi All,

Just a quick email to see if there is a possibility of a small addition/script to Vray in the area of Gi.

For the past 3 1/2 years I have been working as an employee for some of Australia's largest 3D companies using Vray and have recently implimented a full production pipeline change from 2D trees to 3D trees for one of these companies.
During extensive reasearch & testing I discovered one major drawback of using 3D trees over 2D planes which I am sure all Viz artists will encounter as they make this move to 3D trees.

Problem - basically a huge increase in render times if your settings [Irrad map] are using high value HSph divisions.
Also if you have your max value [Irrad map] higher than -2 it will really really slow down render time due to the renderer being forced to sample at the max level due to the complexity of the leaves.

Solution - to enable each object [using Vray object properties?] to have it's own HSph subdivision multiplier as a percentage of the Global Hsph subdivisions.
[I remember Cinema4D's native renderer had a similar type of setup]

Due to their uneven structure Trees don't need a very high HSph [I usually get away with as little as 8-12] as you don't notice any uneveness in the GI & the messy GI solution may actually give some realistic variation to your lighting on evenly coloured trees.
To get a great solution I am often turning the HSph up to 100-150 for complex scenes [with min/max rate usually -4 to -5 min & -1 max which I need to get capture the detail in the architecture. If only I could force the renderer to only sample trees & plants at around 10% the global subdivisions.

IS this possible???? I know nothing of programming & w what is/not possible. I only know you could save hours & hours per render if it is possible to get this idea implimented.


Happy NEW Vray customer

Jamie
Director
3DMK
Australia

[percydaman]

You know I don't have a direct answer to your question, but I can say that I always render trees out as a separate pass, for many reasons, one being what you've spoken of.

[nirsul]

My 2cents: Turn GI generation and reception OFF in Vray Object properties for the trees and other high polycount objects.

NIR

[^Lele^]

An interpolated GI method with such a topologically complex structure is always going to be doing "twice" the work.
Have you tried switching to a DMC GI / Dome setup, to see if those methods are more tolerant of your trees?
You could in theory bake the GI on the trees (provided the lighting doesn't change), and then render them as suggested without GI while the rest gets rendered with IRMap.

All this said, some more per-object control wouldn't be bad at all

[3DMK]

Thanks for the suggestions Lele!!
[I had already tested your DMC method & it is fine for Stills , but unfortunately I am doing more & more animations these days so I need the irrad & LCache solution due to time restrictions per frame.]

I have been told by Vlado that HSph subdivisions per object will be implemented in the next version of Vray. [AWESOME!!!!]

Like you said- more 'Per-object' control would be great in other areas as well. I guess we all have to keep letting the guys know what we need.

Cheers
Jamie

[trick]

...I have been told by Vlado that HSph subdivisions per object will be implemented in the next version of Vray. [AWESOME!!!!]...

Okay: that IS awesome Together with LC interpolation/smoothing per object, this could solve some problems...

[^Lele^]

I'm sorry if i keep punching the same button, but when using DMC GI / Domes, i found out that the rendering goes a wee bit faster if the GI/Dome solution is clean BEFORE AA kicks in.
That may mean raising the subdivs for those effects high enough (say, 24, or more?) from the default of 8.
Rays in Vray have special tasks they are very efficient at,while the camera Rays are generic -hence the very elegant universal setting scenario- and tend to do more work to clean up this or that glossy effect.
This is why i am suggesting a clean GI before AA: done that way it's quick enough that it can be conceivably used for animations (i have rendered a few animations myself, with trees, even though i could get away with some amount of noise, given it was for film and had massive amounts of post).
Ofc, this may still not float your boat, i was merely making sure i said my bit entirely :P

[duke2]

I'm sorry if i keep punching the same button, but when using DMC GI / Domes, i found out that the rendering goes a wee bit faster if the GI/Dome solution is clean BEFORE AA kicks in.
That may mean raising the subdivs for those effects high enough (say, 24, or more?) from the default of 8.
Rays in Vray have special tasks they are very efficient at,while the camera Rays are generic -hence the very elegant universal setting scenario- and tend to do more work to clean up this or that glossy effect.
This is why i am suggesting a clean GI before AA: done that way it's quick enough that it can be conceivably used for animations (i have rendered a few animations myself, with trees, even though i could get away with some amount of noise, given it was for film and had massive amounts of post).
Ofc, this may still not float your boat, i was merely making sure i said my bit entirely :P

Thanks for that tip Lele

[3DMK]

Thanks for more info

Yes,

Thanks again for the explanation Lele! Can't wait to get more time to test it.

Cheers
Jamie

If only there was 25 hours in a day!

[3DMK]

Hey VLADO, How come you're not promoting the new PER OBJECT GI subdivision control in Vray 2.0????? [Under OBJECT PROPERTIES - USER DEFINED]

Finally my dreams came true when I noticed that it HAS been implimented in Vray 2.0 & I can't understand why this is not the latest READ-ME or update log????
This is a huge improvement to vray & I hope everyone out there knows that it is there & can help them heaps with quicker render time

Now all we need is a PER OBJECT Anti-Alias control.......will this ever be implimented

Thanks again VLADO for making our jobs easier with constant implimentation of users ideads

Cheers
Jamie

[Dave_Wortley]

It's in Vray Object Properties as well...