Simulating shave fur dynamics in Houdini

[norse]

Hi. Im really new to Houdini and have, probably, a really simple question.

Im currently working on trying to improve our dynamics pipeline for hair and fur and decided that I wanted to learn Houdini for this purpose(Not really a fan of shave and haircuts built in dynamics). What I want to do is basicly export curves from maya, and then import the same curves in Houdini. I want to constrain them to an animated mesh and have them move with the mesh in Houdini.

There is a similar help scene that comes with Houdini, however that solution did not work for me, probably due to my curves not have the pivot at origo?

I have a continuation on this thread later as well once Ive managed to solve this, either by myself or with the help of some kind person here =D Which will probably start to get a bit complicated hehe.

For this test I've used a sphere with 14 curves attached to it. The sphere itself is animated. I merged the curves so that I only need to have one simulation network(something I will try to write a script for, would appreciate some help on that point to ;D don't even know where to write scripts in Houdini at the moment).

Im using a wireglueconstraint to drive the curves and then a merge node to add the sphere. The center of the guideconstrain does infact move with the spheres animation, however the constrains of the roots of the curves are still frozen in space. Sorry for the bad explanation. Just check the scene and youll se what I mean

Thanks in advance / Henrik

constrainingHairCurves.hip

[brianburke]

Haven't done it personally, but this thread might help:

[norse]

Thank you for the fast answer. The scenes helped me a lot. Although I still have a few questions. So here goes.

What is the best way to import the curves? I notice in the scenes that they seems to be taken in as cached geometry? I imported my curves by using the FBX export from Maya then importing them to Houdini. But that takes forever and doesn't feel like a good solution, say that I have 10.000 curves it takes about 30min or more to import them, at least the 3-4 times I've tried. 10.000 curves is a bit over the top but its not very uncommon that I end up with 4-5.000 curves due to the need of some areas needing a lot of density and also because the use of several hair systems.

*Edit* I noticed the node was just locked so I guess it is an FBX anyway. Still have problems with it being super slow though. Is there some way to work around this or is it just not possible if the curve count gets to high?(I could possibly mention that I can view 10 times the amount in Maya without a problem)

/ Henrik

Edited October 14, 2009 by norse

[dl83]

Take a look at Wire Glue Constraint in your AutoDopNet. By default/By the shelf tools it's going to be constraining based on a point attribute "roots". As your curves coming from Maya have no such attribute, they are not properly constrained. There are a couple ways to add this attribute, but I'd recommend the method in the thread posted earlier for a way to go from Maya (as .iges, since you're doing your animation in Houdini anyway,) to Houdini.

[norse]

Hey. Yeah Ive gotten some help from OWL with the import export, among other things =D

Ive Been looking through some tutorials and have looked through papers and actually tried the fur system in Houdini myself now as well, only a little though. I still havent decided if I like Shave or houdini best though for generating the actual fur. Any thoughts on whats the "best" solution, especially for making long hair.

Thanks for all the help so far =D