Posted by: Jeff | 2013/03/09

Hair Farm and Ornatrix on Dynamcis and Simulation

ornatrix_hairfarm_sims

First off, I would like to mention and thank this great Ornatrix 2 Review by Joe Gun. It inspired me to write down this post. It is not meant to be a concise review, but rather, more of just my thoughts – after trying out demos of both Hair Farm 2 and Ornatirx 2 for a short time (2 days to be exact).

Apart from testing out the basic hair generating features, most of my focus leaned more towards the dynamics and simulation side of the products, as this was supposed to be a quick R&D for an upcoming project.

* updated 2013-03-12
* updated 2013-03-16: Added Hair Farm studies (click this link to view animations/tests).

Here’s a short list of things I liked on both products.

  • Both are modifier based.
  • Both have Vray support.
  • Both have awesome shaders. (Able to quickly render out realistic hair)
  • Both have good dynamics. (but as stated in Joe’s  review, hair systems still somewhat lack in this department)

Hair Farm

Ornatrix

And here are some comparison notes that highlight advantages/disadvantages that I’ve encountered:

Hair Farm

  • I found it much easier to create hair using their HairMesh tech. This is especially advantageous for users who are so used to modeling using polygons.
  • (without the exact numbers) It does render hair a lot much faster compared to Ornatrix.
  • You have a bit more options in doing out of the ordinary hair setups. Like using the Link feature, I can somewhat do a rig where the hair would be sort of ‘skinned’ to it, allowing manual animation. Hair Farm also allows instancing and Wisps where you can use it to create feathers, forests, grass etc.
  • It doesn’t rely on the number of vertices/points in order to get smooth hi-res hair.
  • The dynamics seems to be lacking in realism though, as the system relies on your underlying HairMesh topology (imagine sort of simulating a low resolution cloth object).
    I would need to add HairMesh Smooth in order to increase the resolution for better collisions (which is actually quite nice from a workflow standpoint).

    update 2013-03-12: Did a bit more tests on the effect of a simple HairMesh versus a complex one.

    HairMesh Complexity

    HairMesh Complexity

    A: Simple HairMesh Extrusion (3 levels) on a 1×1 segment plane.
    B: Same as A, but with HairMesh Smooth applied to add more subdivisions.
    C: HairMesh Extrusion on a 3×3 segment plane, applied Vertex Separation, creating thick strand-like extrudes.
    D: Same a C, but with HairMesh Smooth applied.

    * Sample A simulates the fastest.
    * It appears that even if you add more details to the HairMesh extrusion (via Vertex Separation and HairMesh Smoothing), you would typically get more or less similar results for the sim.
    * Notice also that the more details you add to the HairMesh, the more that it would create some folding (noticeable during collision with the pink block).

  • It is also safe to say that sims are a lot more robust compared to Ornatrix, I get to retain more of the overall shape of the hair easily by just selecting portions of the HairMesh that I want to be affected by the HairMesh Sim (dynamics) — also largely due to the feature Gravity Compensation.
  • What it probably lacks is the simulation of smaller strands. But it’s probably just because of the way I created my hair extrusions — thick ones.
  • The Help documentation is a lot more organized and easy to navigate.

Ornatrix

  • Compared to Hair Farm, I much prefer the look of the dynamics Ornatrix gave. It was a lot more fluid.
    But I had problems figuring out how to retain my combing once the dynamics kicked in.
  • I was also looking into the Wisp generation feature (wisps in Ornatrix is different from the wisps in Hair Farm) to control how the dynamics behaved – the visual display in the viewports is helpful to gauge its size (although it might be a lot more useful if the display is similar to the ones shown in their online help – where you may see intersecting wisps).
  • Another concern is that during simulation, you don’t get to have the viewports updating. You would have to wait until the simulation is done in order to view the result. (I’m not sure if it was because of my hardware setup.)
    update 2013-03-12:  max2013 viewport updates works fine.
  • The Dynamics Presets can also be a useful starting point for playing with the settings. Like with most dynamics systems, I initially had trouble setting up the parameters. I realized that most values needed to be set quite high in order to see the effect. I have yet to find the proper scaling of my scene.
  • Although Hair Farm also has minor manual combing features, Ornatrix so far is the best I’ve used for combing. I love the response I get from editing the guide hairs. Braiding is also a breeze to create. Surface Comb is one of the best features it has for initial hair combing.I suppose the advantage Hair Farm has is its ease of use, you basically just need to have a basic background in polygon manipulation in order to start modelling hair. In Ornatrix, the advantage would be is to get used to how the comb responds to your strokes, once you’ve caught the drift, I believe it can result to outstanding hair sculpts.

Conclusion:
I was looking for a good solution in doing realistic hair that I can animate manually. The hair also needs to do some out of the ordinary stuff like stretching-out and grabbing on to things.. basically it needs to be ALIVE.

Considering that these are just quick tests for each product, nothing too extreme. The company I was working for went and bought Hair Farm, the main driving factor was we needed more control on ‘animating’ the hair versus ‘designing’ hair. Fast realistic renders was also a selling point.

Other Notes:
Also note that even though I actually prefer the simulation result of Ornatrix, it lacked the manual control that we needed. But I’ll be sure to check back on Ornatrix from time to time. I believe Blur studios wouldn’t have used it if it was not that amazing.

ipdate 2013-03-12: It appears I missed a very cool feature in Ornatrix (thanks to Micheal McCarthy for the tip), the manual control that I noticed it lacked came in the way of Ox Hair Shells.

Ox Hair Shells

Ox Hair Shells

As you can see, the feature allows hair generation via ‘Shells’ made out of plane objects. These shells can both be used to model AND animate hair. Though it doesn’t seem to affect world space translations, your control will rely on animating the shells via modifiers, where eventually this will become the backbone of your hair dynamics.

References on the Web:
Hair Skin-wrapped on Cloth
Here’s an interesting method by Juan Gea from Bone-Studio on controlling hair dynamics —
Hair Setup – http://bonestudiotech.blogspot.com/2009/11/hair-tufts-and-hair-clumps-easy-road.html
Hair Cloth – http://bonestudiotech.blogspot.com/2010/06/hair-tufts-and-hair-clumps-easy-road.html

Other Ornatrix Usage Examples
CG Porcupine by Yoni Cohen on Youtube (Hair Shells)
Creating a CG Rooster by Yoni Cohen on Youtube


* Lastly, this is coming from a guy (me) with little to no experience on working with hair. ^_^ I hope these notes would help other users curious about user (very short) experience regarding both products.

* Thanks to Micheal McCarthy for the additional tips and info regarding Ornatrix.

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Responses

  1. Great comparison. Thank you!

  2. Great work Jeff. It’s nice to have these comparisons to look at.

  3. Thanks guys, I have updated the post, as I’ve learned a few other features that I was not able to tackle during my quick testing period..
    Namely the Ornatrix Hair Shells ^_^


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