Hiar Dynamics, Collisions, Force Fields... How?

I’m feeling baffled by particle hair, which I’ve just returned my attention to. For simplicity, consider a pony tail. I want it dynamic, responding to gravity, and to not intersect the character’s body. I can’t make it work.

From searching the internets, it seems that hair collision doesn’t work(?) so I try a force field from another object (simply, a cube for testing). But if I have Hair Dynamics enabled, the hair doesn’t respond to the Force Field. Am I doing something wrong? I just want a pony tail to fall under gravity, and react to motion, and not disappear into her back. How?

Hair collisions (and clothes,etc…) are very “buggy” in Blender…
I’ve just tried the hair collisions: on the hair dynamics tab you can try setting at 1 the collider friction.
Then select the colliding object and set that as collision object on the physics tab. This last will need a very dense number of vertices, otherwise hairs will slide inside the mesh much more easily.

Don’t bother fighting trying to get hair collisions in Blender right now. Hair has been broken forever, and is currently in the process of being rebuilt from the ground up. If you need it right this second, you can try building the Gooseberry or experimental hair branches. But struggling with the existing hair system right now is just an exercise in futility.

So I’ve noticed… One thing I noticed about hair dynamics early on was the fact that hair particles do not respect collision boundaries as can be seen in the following image:


Okay, I’ll leave it for now then.

Is there any kind of indication of when a fixed hair system might be ready for use. It would be really useful. And, other than keeping hair short and out of the way, how are people dealing with the lack of collisions at the moment?

Personally I use a mixture of force fields, child hair radius and camera angle. Not much else you can do at the moment.

They are reworking the entire hair system as a part of the gooseberry project, so probably sometime later this year.

Actually, it was Tuesday. :wink:

http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.74/Hair

Nice.

Well, it will still be sometime later this year when the stable official release comes out, so I’m still right. :RocknRoll:

I’m a bit confused. This is for 2.74 which isn’t out yet, but not in 2.73, right? I haven’t yet updated from 2.72b.

Right. You can download a nightly build from the buildbot if you want to play around. Just be warned there may be bugs. Maybe not so much with the hair stuff itself (since that’s been battle-tested on Gooseberry already) but there’s some other stuff in there that hasn’t gotten a lot of production testing yet.

Well since I’m a noob and never know whether something is a bug or my own idiocy, I’ll wait for the official release. I’ve lots else to do in the meantime. The changes in the documentation certainly look good though and not just collisions; the spring model will be a great improvement. So, I hope it isn’t too long before 2.74 is official :slight_smile:

I am definitely testing this out…right now (as soon as I download the build).

BiggR, please report back your findings :slight_smile:

After checking out the latest builds, I still cannot get the collisions to work. I have been playing with the settings (which are now really nice) I cannot get the hair to be affected by a mesh (other than the old force workaround). Not sure if I am doing something wrong. Any help would be appreciated…

Are they affected by their parent mesh?

No. I cannot get them to collide with their parent or any external mesh.

Is the Gooseberry hair branch actually in the current builds?

I checked both the gooseberry and the main branch. There are some subtle differences (hair dynamics pinning, for one), but on the whole they are now the same.