Fuzzy Hair render

VoidOVoidO Posts: 42
edited December 1969 in Carrara Discussion

I have a problem with the lighting interaction with layers of hair (fur).

Here is the panda rendered on green screen, and see the black/white flickering in the render, where I believe it's the hair layers that just don't get the light good, or I did something wrong with the render. Beware the 17MB: http://www.voidorchestra.com/wip/Fluffy_pre_comp.wmv

What's causing this? Is it lighting? is it that the hair just move way too much? Is there a way to make hair stop moving, more than setting the shape dynamic to 500%? Should the lighting still be more gentle with the hair? Should there not be an anti-aliasing thing I can use? I just need a pro's opinion.

Here is where the final is used: http://www.youtube.com/watch?v=BRTozdmPejk


  • evilproducerevilproducer Posts: 9,031
    edited December 1969

    I'm not sure about the unwanted movement, unless the styling tools create keyframes?

    For the hair layers, what many people do is use one layer, and let an underlying texture map help sell the under-coat.

    Some of the flickering could be the anti aliasing settings. What are they set to? I would at least have the shadow accuracy and object accuracy set to the same setting. With hair, you may want a .5 pixel by .5 pixel accuracy at the good setting.

    Another thing to think about is to just render with an alpha channel. No need to knock out the background later. That also may help with the flickering on the edges of the ears and such.

    I don't really animate much with the hair as I have an old computer, so some of what I'm suggesting are just educated guesses. Some of it is what I've gleaned from reading others that animate using the dynamic hair.

    PhilW is a great source for information about animating dynamic hair here in the Carrara discussion forum. If he doesn't see this thread, you may want to try PMing him to pick his brains a bit.

  • evilproducerevilproducer Posts: 9,031
    edited December 1969

    Great animation on the Panda by the way!

  • VoidOVoidO Posts: 42
    edited December 1969

    Ok... call me uneducated, but the option "Render Alpha" is grayed out in my render pane. Why's that? Just can't find it.

  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    telecino said:
    Ok... call me uneducated, but the option "Render Alpha" is grayed out in my render pane. Why's that? Just can't find it.
    To get alpha you will need to use a render format that supports it, like PNG Sequence or QT Animation.

    Cute panda! I think your highlights are too strong though.

  • PhilWPhilW Posts: 5,114
    edited December 1969

    You mentioned having fur layers, and if you have multiple layers in the same place, that may be the issue, as Carrara has some rendering bugs when you have two or more hair layers in the same place. You can use the object map to color the hair, so you can use this to give the correct black and white pattern from a single layer of hair.

    As others have suggested, I would use 0.5 for object accuracy, as hairs are fine and higher settings can miss parts of the hair on some frames. Shadow accuracy is less of an issue I think. As long as you have some level of anti-aliasing, that should be OK too.

    I hope that helps - let us know if the advice so far solves your issues or if you are still getting problems.

  • evilproducerevilproducer Posts: 9,031
    edited December 1969

    I just found that if the shadow accuracy and the object accuracy are the same there was less of the sparkle effect on terrains which can have a lot of details in the color and bump channels of the shader. I figured hair may be the same way since the detail is so fine.

  • VoidOVoidO Posts: 42

    Resolved flickering hair in Carrara:

    The problem was that hairs are bobbing intensely between each other, and are too affected by the dynamic/physics engine, which causes their position to change dramatically on each frame. Added to that the anti-aliasing too corse, the flickering effect happened.

    The keyword is: Stiffness.
    I adjusted full (100%) stiffness at the root, hair, every slider on the right (one of them shows 500% instead of 100%).
    I removed air effect (set to 0%)
    I added more segments to each hair group (6 instead of 3)
    I have 2 hair layers instead of 5. Less realistic hair, but no flickering.
    I set the rendering options Object accuracy to 0.5, and Shadow accuracy to 0.5, quality to good.

    I'll post a render one the final video is done.


  • PhilWPhilW Posts: 5,114

    If you are using fur on an animal, don't even do a dynamic hair simulation, the fur will just move with the character but it doesn't need to respond to other forces.  I have got around the flickering issue on human hair by using low-poly proxies. The issue is caused by colliding with objects that have tens of thousands of polys (ie. your character!) and it is just too complex to calculate accurately. I therefore use lower poly proxies attached to body parts (mainly the head, but you might also need shoulders depending on how long the hair is), which not only speed up the calculations but avoids the flickering effect.

  • VoidOVoidO Posts: 42

    Thanks. Never tought of using proxy objects for simpler colisoin calculations. Very good trick.

  • PhilWPhilW Posts: 5,114

    You can see some of my tests here:


    and my latest Carrara Adrea Hair product uses proxies and is set up to be "animation ready"


  • VoidOVoidO Posts: 42
    edited December 2015

    Here is the final render of Fluffy the Panda. Watch in HD to see the individual hair.

    Every 3D piece in this video was done with carrara. After Effects for the EQ and animated lighting FX.

    The music is an Electro House version of the classical Funeral March of a Marionette, composed by Charles Gounod in 1872.

    Post edited by VoidO on
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