hey everyone. i'm a little new to cinema 4d, but i'm having some MAJOR problems with the hair module.
i did a test render of a model i'm working on, moving it from left to right, and then rotating a little. the hair is penetrating the head mesh, acting really bizarre and jutting out in random directions, and it appears like some of the hair is actually moving AGAINST the dynamics, meaning: the hair is moving backwards, except the eyebrows and sideburns are moving forwards.
i've added a hair collider tag to the head mesh. is this wrong? once i've add the tag, do i have to specify anything else? i know i'm missing something. i just have no idea what.
Re: bad HAIR day by Brian Jones on Jun 9, 2008 at 3:47:48 am
Hard to know without the scene but - are all the polys aligned? What kind of forces are there (bounce, friction etc), and it looks like hair is intersecting the mesh at the end, so again the question about the mesh - are the normals aligned and pointing outwards?
Normals detection depends on the view options you have selected. By default normals tinting is turned on, so if you have all polygons selected and they're all tinted the same color, you should be okay. You can also (in view properties) turn on normal lines, which are small lines that project from the center of polygon in the direction the normal is facing.
i did an "align normals" function an re-rendered. i'm still getting similar random extreme jutting like in the first render. it appears like the hair isn't passing through the mesh AS MUCH...but it's still there.
thank you all so much for your help, i'm just totally confused as to why this is happening. i did a test render with a sphere and a hair object, doing the exact same motion, putting the hair collider tag on the sphere, and it worked like a charm...of course this was all at the defaults. is there something in the hair material that i've messed up in trying to make the hair look like it should? could it be something in the hair OBJECT itself that i've tinkered with? i'm so lost. it doesn't make any sense.
Re: bad HAIR day by Brian Jones on Jun 11, 2008 at 10:38:10 pm
if it works well in a test then it should work as long as Surface to Hair is checked in the Hair Objects Forces tab... how was the head built? I wonder if you've got polys doubled on top of each other or something.
ok. this is probably the absolute WRONG way to go, but...
1. i started with this stupid program called "facegen" and used 3 pictures of my face to start building.
2. not being too pleased with these results, i took the model into zbrush and finished modeling there.
3. i pulled that into UVLayout and made the UV maps.
4. i took it back into zbrush for texturing my face onto it.
5. added hair in c4d.
the only other bit of info i can add is that A: the thing has a lot of polys. B: the hair is a few layers. is this dumb? (ie: sideburns are one hair object. eyebrows are another. then each part on top of the head is a hair object)
i'm pulling my hair out (no pun intended) trying to figure this out. short of scrapping the whole thing and starting over, which would kill my soul, i'm not sure what to do.
Re: bad HAIR day by Brian Jones on Jun 12, 2008 at 4:22:53 am
Sounds like it might be a needlessly complex model, maybe with redundant polys right on top of each other, possibly with some strange Normal stuff going on. We'd have to see the model to tell. You might want to look at one of the head tutorials out there (sorry don't have a good link at this point - anyone know a good one?) If you build simpler heads but this was just unusual, ignore me :-)
If you had a cleaner simpler mesh the chances it working would greatly increase.
Hair layers should be no problem - eyebrows, sideburns particularly - but how many Hair objects are you using for the main hair? By the look of it one should do (maybe a couple but it's not a bizarre hairdo)
Some more thoughts, what are the bounce and friction settings of the hair objects? And do you have any Hair to Hair turned on in the Hair objects Forces tabs?
Re: bad HAIR day by Brian Jones on Jun 13, 2008 at 11:56:10 pm
I would think Hair to Hair is not needed by the look of it, you might try it without.
Sure I could check it out. Do you have a place to post? or you could send it to my firstname.lastname@example.org email (that one already gets a load of spam so I have no fear of bots).