Pulling out (my) Hair [venting post]

Setting up cloth simulation is a piece of cake.

Really.

You should try to setup a workable, reliable and usable hair simulation and you will agree with me.


[warning, rant ahead]

Static hair setup in itself is a tricky endeavor, but can be handled with patience, some know how and the will to make compromises. One of the many compromises e.g. was to stay away from curly hair, although this was high on my wish list. Well I could just comb the hair to get curls, but I really want to have the movie finished in my lifetime.

My last post showed the preliminary results of my static hair experiments, with the almost prophetic statement, that this may not stay this way once animation starts. With animation I mean hair with softbody simulation to give a nice fluid movement and good interaction with wind.

Quite frankly, hair with softbodies ( in blender 2.49) is a nice demo feature for carefully tweaked shots, but just forget it for serious work, especially with long hair. This system is so sensitive to what you do and in what order.

Every so often I got just totally messed up hair after a few runs of softbody simulation. Sometimes it was just enough to move the actual frame on the timeline. Tweak some hair parameters while the softbody simulation is still on and you get a 50:50 chance for a total mess up. I had 4 times where my basic hair setup was totally messed and I had to start from scratch again.

This all is accompanied by the fact that hair softbody simulation with collision detection (not self collision) is almost a magnitude slower than cloth simulation and stretches your patience even thinner.

After a long time tweaking I somehow got a very shaky and tedious workflow going and went on to the next step: adding wind.

HA!

What a heap of ….. !

Wind alone is immediately visible on the hair without the need of any softbody simulation. So its nice to adjust the strength. But what happened in my case was that the force direction of the wind changed by 180° and increased in strength once the softbody simulation was activated, but only for the hair of course.

I still have no real idea what exactly is causing all these problems, but it got me immensely frustrated. So much in fact, that I consider skipping the long hair for Ara. If 2.5 is not better with this I really do not envy the durian team with their task. Bick Bug Bunny had it better as they didn’t use the softbody simulation.

And in an incredible masochistic move I tried to use the hair system for the brows and lashes. For full control over the shape of the brows and the individual lashes you must not use children here. But with children disabled you have no longer the child simplification which is necessary to counter to hair scaling problem. This results in extremely bushy brows the farther away you are from Ara.

Conclusion: brows and lashes will be painted.

[/rant]

If anyone has some good advise I am all ears.

In the meanwhile I will try to keep the long hair and trick, hack, bite, weep, shout and smash the hair for each shot in place.

( … and I may book a nice room with soft walls in our local psychiatry … )

7 thoughts on “Pulling out (my) Hair [venting post]”

  1. The only thing that immediately springs to mind is perhaps to have a secondary particle system to add in curly bits.
    I’ve no idea if this would actually help!

    Also you could have different eyebrows depending on the specific shot, ie uses painted eyebrows when the particles don’t work out, but particles when they are predictable.

    Good luck, your blog is inspirational! 🙂
    Stuart

  2. Hi Stuart

    Thanks for your thoughts.

    Adding a secondary particle system for the hair might work ( but I doubt it ) but would double if not quadruple the problems encountered with hair and softbodies so far. For now I have accepted the look of her hair.

    As for different setups for the eyebrows, this would work if you have clearly separated shots. Unfortunately there are some shots where the camera moves from an extreme closeup to a wide shot (or vice versa) without a cut, so this is clearly a case against this technique. Besides having two setups for the same thing requires a lot of tuning so you do not to run into any continuity problems.

  3. *sigh… never a quick fix in blender… i have the same problem… have you considered using alpha mapper planes? check out the Kata project on blenderartists

    1. I never seriously thought to use alpha mapped planes. It’s also not an option now as I have now a working setup. But thanks for the hint about the Kata project. I will have a look at it.

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