hair, a simple observation

WendyLuvsCatz

I had a eureka! moment yesterday playing with dynamic hair

forget all the fancy settings and stuff

one simple thing

DO NOT DRAPE IT!!!

ever

styling it and adding lots of segements seems to do the trick and upping shape, itterations etc as expected

I found simulations FIGHT the drape, OK my hair sims leave a lot to be desired but this one thing seems to be the difference between wild hair and reasonable hair/fur in animations

I made the mistake we all do of thinking one must drape hair first so was doomed from the onset.

and most premade styles include a drape in their creation.

I hope to have something to show eventually, just experimenting at the moment,

but in the meantime maybe the more skilled can also try styled simulations without a drape and see where it leads.

Headwax

thanks for that tip Wendy

Jonstark

Interesting, and I actually kind of agree with this, at least for long hair styles, I like to start it 'in the air' sticking up and combed down into the general area, and tack on an extra second or 2 of the animation before there's any movement of the character, to let the gravity pull the hair down into place and have it 'settle' naturally.  I usually don't get the 'hair jumping around like its having a seizure' unless I've accidentally pulled some of the guide hairs into a position where they are crossing inside the mesh of an object they are able to collide with, but the easiest way to avoid that is to have the hair 'up' and let it settle down naturally before the actual animation movement of the character begins when doing the physics sim.

WendyLuvsCatz

that linked vid btw is the same hair no drape and with drape, in the latter it actually flies up as you can see

I must study your thread too JS but was amazed at the simple differrence not draping it made.

PhilW

I'm not sure about not draping the hair, but I think I get where you are coming from.  If you drape the hair, create a nice style etc, and fix the hair like that, then when you run a simulation, it will try to drape the hair again which can pull it out of position.  A trick I discovered recently for more styled hair, is to reduce the level of gravity when doing the simulation.  Setting the Style control in the hair dynamics panel pulls the hair back towards it's defined style, but it seems very strong, so a low setting (only a few percent) gives better results, but then it is not strong enough to counteract the effects of gravity (which are effectively already modelled into the hair through the styling or an earlier drape).  So reducing the gravity to around 10% of normal - if only for the duration of the simulation - helps keep the style.  That is how the vid below was done.

https://www.youtube.com/watch?v=uPRbHseZMt0

But it will depend on the type of style you are doing.  A long free-flowing style may be best doing like you say, and leaving the drape to be a part of the simulation.

BC Rice

Nice test Phil. I'm interested to see how dynamic hair stuff would mesh with my workflow. I don't use individual hairs with my characters, I prefer to use the base model with no fine transparencies and all that. I'm curious to see how physics would work with those.