VrayforC4D+Hair=AA problem

[mala]

Hi Everyone,
Bit scared posting here as it seems to be where the big boys hang out...I've been watching for a while and am in awe of the work posted here:notWorthy:
But hopefully that means there is the experience to be able to help me..

I'm working on a character modeled in C4D+ZBrush and rendered with VrayforC4d...not sure how many people here use this version of Vray..but i can see there are plenty of Vray/Max users.

With VrayforC4D we can use Cinemas Hair plugin(a very nice Hair solution i've found)and when its set to generate polys,the result can be rendered with Vray..the Colour/spec channels can be "plugged" into the diffuse channel of your Vraymtl if you want....but it can be tricky,so i tend to just use the hair "modifiers" of the cinema Hair material to style the hair and do all the rest with a Vraymtl..

Anyway to the point.. the hair is generating 100's of thousands of thin polys,so i have a real problem trying to find a decent AA solution at an acceptable render time...does anyone have any suggestions that may help?
I have a sneaking feeling the answer will be render Hair with C4D-AdvancedRender and comp with the rest rendered in Vray,but its worth asking.

BTW,I have posted this question a few times over at the VrayforC4d forum,but none of the replies so far are helping,i think here there are more people interested in character work..unlike the vrayforc4d forum which is mostly archviz.

Thanks for any advice you can offer.
Cheers,
mala

[gjpetch]

I use vray for max, so I'm not sure if it works differently in c4d, but are you using DMC sampling or adaptive subdivision? DMC should work better for small details like hair.

[mala]

Thanks for the reply Greg,

I don't think there are too many if any differences with AA between Max and C4D versions.

The settings i have at the moment(for the image above) are:
Adaptive DMC 2x8x threshold 0.002 and Area Filter,have also tried 3x9x.

The DMC is set to default but have tried it as low as 0.5

With my original version of this mesh,which was scaled approx. twice realworld sizes i.e model was about 330cm tall,there was much less if any problems with AA on the hair.This was with pretty much the default AA settings.

I rescaled the mesh to make it a realistic size(total height 158cm) mainly because i was getting in a mess with trying to get the SSS2 shader right,when i remade the hair,it was of course thinner,this is when the problems started...wondering if i've passed some kind of limit here.

Cheers,
mala

[gjpetch]

Not sure why that would be happening. One weird quirk with vray AA that could help you, (or not, sometimes this stuff feels more like voodoo than science) turning your glossy samples up to 100, and your DMC AA settings to 2 to 32. Sounds crazy, but those settings can render faster than lower settings.

[mala]

Hi Greg,
I tried your suggestions,unfortunately i ended up with a 7.5 hr render! and not much improvement...i know exactly what you mean about the voodoo some things in vray don't make too much sense to me...but maybe just cos i'm a noob.

My easiest solution to the AA so far, seems to be to render to twice the size and the downsize later,this seems to clean most of it up,but not ideal.

Cheers,
mala

[ianucci]

Hey Mala, maybe try the gaussian filter? Might have to turn it up to 3 or 4 to get rid of all aliasing. It will be quite blurry so you will probably have to do a larger render to get the detail you want, but maybe it will give a better result with regards to render time and quality.