Vray hair material

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  02 February 2012
Vray hair material

With the newest update to Vray there is now two vray hair materials. I'm trying to find any documentation or examples for the Vray hair material 2, but without luck.
Does anyone know if this is documented somewhere?

So far I haven't been able to create realistic looking fur/hair with the new materials, compared to renderman.

Edit: I am using Yeti 1.0.6, unfortunately I cannot show any screenshots due to copyrights.

Last edited by Kyron : 02 February 2012 at 02:25 PM.
 
  02 February 2012
Same here! I haven't been able to find anything other than the video on Max and really need some info in regards to render settings etc to make this work.

Cheers!
__________________
"Knowing is not enough, we must apply. Willing is not enough, we must do."-Bruce Lee


 
  02 February 2012
There should be no need to use VRayHair2 material; the VRayHair3 should work much better. Note that you really need GI for realistic hair. The recommended settings are light cache for secondary GI with "retrace threshold" enabled, and brute force GI for the primary GI bounces. Adding tip-fade transparency might help for a better appearance of the material.

Some examples are available here:
http://spot3d.com/vray/images/stuff/hair_tests/
http://www.spot3d.com/vray/help/200...vrayhairmtl.htm

The recently released FarCry3 trailer has some examples from an actual production

Best regards,
Vlado
 
  02 February 2012
How do you add that in Vray for Maya? So far I have tried mapping a vray fur sampler to a ramp
(distance along strand > rampVcord) but the hair still looks a lot like it has just been cut off with no taper or falloff.
 
  02 February 2012
Thanks a lot for those links to the docs and examples, Vlado!

How high do you have to crank up the quality settings to get noise free renders and how long do they take on average with ie Maya Hair? I've been briefly trying in Maya and though without any real instructions other than the Max/Ornatrix video was able to get something decent looking in roughly 2min plus, but its still far from what I would call production quality in regards to noise on hairs with thickness of 0.10 or 0.015 and 100% opacity/zero translucency for testing on a real-world scale model and HD720 render-output.

Kyron: I'm not sure what you want to add, but in case you want to know how to add the VRayHair mat, go to, I think it was the paintFX tab in the AE > Top Menu >Attributes > Vray > HairMaterial. I could be wrong, but I think it was something like that. Then you'll have a VRay Extra Attributes section at the bottom with the parameters etc. I think the tip-fade transparency attribute can be found there as well.

Cheers!
__________________
"Knowing is not enough, we must apply. Willing is not enough, we must do."-Bruce Lee



Last edited by TheRazorsEdge : 02 February 2012 at 10:21 AM.
 
  02 February 2012
I second TheRazorsEdge`s question and would like to add that animated examples would be great.
__________________
Digital Characters R&D - Suntoucher Labs
 
  02 February 2012
Hey Vlado and Felix.
Thanks for the replies.

Felix: I am not using PaintFX but Yeti. I assume you mean if you have a Maya hair system you can add an extra vray attribute and plug a vray hair shader into it?

Vlado: I am working on a scene with a mouse and I am trying to create a look a bit like this, except I need the fur to be a bit more "fluffy" or soft (if you have a fluffy cat, turn it over and look at the fur on its stomach, it feels like an angels hair). Also with some nice rim lights on it.
I will ask tomorrow if I can upload an image or maybe PM you if you don't mind.
 
  02 February 2012
I played with it again a bit yesterday, but for the heck of it could not produce a relatively noise-free render in say 5min's of rendering. I still need to read through the docs, but I think more info is badly needed here. Also, some hair-quality rendering presets, like there are for Mental Ray would be nice to have.

Originally Posted by Kyron: Felix: I am not using PaintFX but Yeti. I assume you mean if you have a Maya hair system you can add an extra vray attribute and plug a vray hair shader into it?


Christian: Aha, Yeti! How does that compare to ie Shave?

Yep, that's what I meant. Only that I got the instructions a tad wrong, since I only did it once and on pure instinct. lol Here's the correct way for Maya PaintFX hair:
hairSystem > AE > hairShape-tab > "Top Menu" > Attributes > Vray > HairShader.
This adds an extra attribute to the bottom of the tab, where you can add the VRayHair3 material. When you edit the options, use a preset to get started. However, maybe I'm blind, but I don't think I saw the tip-fade transparency attribute there.

Cheers!
__________________
"Knowing is not enough, we must apply. Willing is not enough, we must do."-Bruce Lee



Last edited by TheRazorsEdge : 02 February 2012 at 10:31 AM.
 
  02 February 2012
We used to use Shave but the idea is to switch to Yeti. I can't say how it compares since that is not my department, but I do know that our rigger seems to enjoy it .

The way I get a tip fade is as I described earlier plug either a vray hair or fur sampler into a ramp, and the ramp into the opacity. Top of ramp should be black and bottom dark as a starter (so it will fade) and play with the ramp settings to get the taper you are after.
 
  02 February 2012
Originally Posted by TheRazorsEdge: I played with it again a bit yesterday, but for the heck of it could not produce a relatively noise-free render in say 5min's of rendering. I still need to read through the docs, but I think more info is badly needed here. Also, some hair-quality rendering presets, like there are for Mental Ray would be nice to have.


Must say, I've had pretty amazing success with the shader so far apart from a few nits (texture mapping is still a somewhat strange and flakey workflow).

It's almost as fast as comparable hair shaders in Houdini/Mantra (that don't require raytracing). In fact, I've been pleasantly surprised at how quick and relatively noise-free it is by default.

There's a possibility that it's feeling slow to you because your lights are too noisy and the image sampler is working too hard.

Try using adaptive DMC, 1-24 subdivs with a threshold of .007 under both antialiasing and dmc settings. For subpixel thin stuff, I generally lean toward Cook Variable AA at a radius of 2.5.

Start with no GI at all and straight up VRay rect lights (crappy HDRs add a LOT of noise to anything). Once you tune the light subdivs up to the point your rawlighting is clean, add brute/brute GI at 24ish subdivs/3 bounces.

--T
 
  02 February 2012
Thank you very much for those tips and settings, Trey. I'll try them out later today.

Cheers!
__________________
"Knowing is not enough, we must apply. Willing is not enough, we must do."-Bruce Lee


 
  02 February 2012
What exactly is your workflow for the hair Trey?

I plug my color texture to the overall color slot and then create a black and white ramp from bottom to top. Then assign the distance along strand of the fur/hair sampler to the V coordinate of the ramp. The ramp then goes to the transparency to create a falloff.

Anything to add?

Regarding Yeti, it is still fairly new and we seem to get an update every morning I come to work, so I think its safe to say it is not flawless. But as I mentioned in an earlier post, our rigger really loves it compared to Shave .
 
  02 February 2012
Originally Posted by Kyron: What exactly is your workflow for the hair Trey?

I plug my color texture to the overall color slot and then create a black and white ramp from bottom to top. Then assign the distance along strand of the fur/hair sampler to the V coordinate of the ramp. The ramp then goes to the transparency to create a falloff.

Anything to add?

Regarding Yeti, it is still fairly new and we seem to get an update every morning I come to work, so I think its safe to say it is not flawless. But as I mentioned in an earlier post, our rigger really loves it compared to Shave .


Without getting too detailed... I plug the hair sampler's hairColor attr to hair3's diffuse, and I've been using the ramps on the hairSystem's shading rollout to control root to tip fade, hsv jitter etc, and mapping the hairSystem directly (streaks/highlights go via blend overrides on individual follicles if you want those). One weird glitch is that there's a Maya bug which will break your UV linking if you try and gamma correct anything going into the hairSystem... so you'll need to correct the outputs of the hairSampler instead. It even breaks the viewport preview, so it's not a VRay bug there.

Looking forward to playing with Yeti soon.

--T
 
  02 February 2012
Thumbs up

Anyone can post some images test ? (with render time)
And animation test ?

Thanks.
 
  02 February 2012
Ok, I tried out Trey's settings and while they appear to yield nice, albeit rather smoothed out results, I canceled the render about less than 1/3rd through, after about 7mins on a Core2Quad 2.6Ghz machine for a HD720 render of production-type hair-density (Maya Hair) on a basic sphere, but without anything else in the scene other than a ground plane for shadows and 1x key/1x fill light.
I find these render-times anything but "unprecedented", since I get comparable, if not better results with 3Delight in 1.20mins for the very same scene, but of course with Maya lights, 3delight shader and Deep Shadows. RFM results are similar to 3Delight's and even Mental Ray with Unified Sampling and the p_hair shader appears to do better than VRay.

Anyways, many thanks to Trey nonetheless for these settings.

I have to say though that I feel kinda played for a fool by ChaosGrp. The only video with kind of usable information is the one on Max, but even there the Ornatrix hair appears to me as unusably thick and actual information on production-type settings is more than "limited" (too bad I don't work with Ornatrix and dont plan to either).

To my knowledge there is no video yet for Maya and the one for Softimage shows us some sweet little shading tricks for funky colors, but nothing about anything that really matters, like render-quality settings etc. Jimmy without fail tells us "it's very fast to render", and I am wondering on how many cores/machines he is doing that for the video, 'cause I can't reproduce anything even remotely like that in Maya on a single machine with admittedly puny 4 cores.

The docs are rather sparse and have so far not done much to get me successfully rendering hair in VRay/Maya.

Well, unless they're going to publish some useful info that actually helps me along the way soon, I'm going to have to throw the whole "hair-rendering with Vray/unprecedented-blablabla" thing into the can and make some mental notes about ChaosGrp marketing strategies. My "VRay For Softimage" purchase considerations are "gone with the wind" indefinitely for sure now, especially if there's not going to be some kind of a package deal for AD Entertainment Suite clients. And as crazy as it may sound Maxwell Render now sounds like a good thing to test for hair-rendering next. lol

Cheers!
__________________
"Knowing is not enough, we must apply. Willing is not enough, we must do."-Bruce Lee



Last edited by TheRazorsEdge : 02 February 2012 at 01:39 PM.
 
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