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View Full Version : How does this whole Hip thing work?!



rtl114
03-05-2009, 05:28 AM
Hey All,

About every so often I try to get a character rigged. I have very little call for 3d in my professional work, so do not get to do much character animation. I always seem to get so far, I get the knees and the ankles rigged just fine, BUT thenÖ. I come to the hips. OH THE HIPS!! And for some reason, I cannot for the life of me get them rigged, so they bend half way decent. You guys that make the videos and tutorials all make it look so easy, but mine come out looking like crap. The mesh at the hip collapses in on itself. Iíve tried everything (well, everything I know of) different weights, holding bones EVERYWHERE, morphs, changing the geometry, but to no avail. Iíd love some tips or advice on what I might be doing wrong. Iíve included some images of the mesh, weight mad, and bone set up (Iím using 9.6ís joints). Iíve also included what happens to the mesh when the joint is bent. I donít have the model and scene with me, but I can upload them to if it will help. Iím almost at a point where Iím willing to pay someone to rig the character for me (but, not sure the wife will approve that expense :-) ). Thanks for any advice you may have.

Ross

adamredwoods
03-05-2009, 11:07 AM
You may need another bone-- a hold bone. Offhand, I would try putting the base attached to the hip bone tip.

Or you can do a joint morph.

Tranimatronic
03-05-2009, 01:40 PM
Id start fading your weight map for the upper leg about 4 polys lower.
I often thought the more bones in areas like this, the more scope there is for stuff to go wrong, so Id also simplify your rig also - one backbone splitting into two for the legs. Remember you dont HAVE to have a map for every bone.

Mr Rid
03-05-2009, 03:45 PM
I think this could be a good thread for CA. I never actually see realistic hip or shoulder deformations in LW rigs. Most characters get by with cartoony proportion or are obscured by clothing.

Usually I only need loose human rigs. Recently I needed something more detailed and was stumped particularly on getting hips, crotch & buttocks, as well as shoulders to deform naturally through out a range of typical human motion. Something is always stiff, pinched or stretched oddly and attempted fixes only became overly complicated. I really despise using weights maps and keep wishing I just could click & drag to draw an influence falloff along each axis of a bone, or be able to use texture maps instead of weights which are much more versatile and intuitively editable.

zapper1998
03-05-2009, 03:59 PM
I agree with Mr.Rid on the thread for CA..

Castius
03-05-2009, 04:14 PM
That's because weighting is not really enough to get good hips. As you said you get some pretty good results but then you hit a point that doesn't work. You can add hold bones but i prefer those bones to animated for have some basic rig setup to act as a muscle or tendon. Or corrective moprhs.

Joints make basic muscles easy to setup. You could makea joint parented to the hip. Then point constraint the end of the joint useing "same as Item". The the thigh. This would act as a basic look at deformer. As long as you dont' go past 90 degrees this could behave likes a simple muscle. If you wanted to go further you could use scaling IK.

Castius
03-05-2009, 04:45 PM
Here is a quick test.

geothefaust
03-05-2009, 04:46 PM
I'm dealing with the very same problem at this very moment. Go figure.

I'm finding that a good combination of weight maps and hold bones can get a pretty close look. Granted, maybe not as good as I would like, but it's close.

Hey Scott, thanks again, I never thought of doing that for muscles. Good idea.

adamredwoods
03-06-2009, 11:10 AM
If you're really interested in developing a great hip rig, someone may have to post a model to rig.

bazsa73
03-08-2009, 01:57 PM
Hi folks,
For those who need a free human model, I think it's more than enough for a start:
http://www.newtek.com/forums/showthread.php?t=96002

Mr Rid
03-09-2009, 01:39 AM
If you're really interested in developing a great hip rig, someone may have to post a model to rig.

C'mon folks, DAZ already.

Michael 4 and Victoria 4.2 are FREE.

http://www.daz3d.com/i/3d-models/main-figures/victoria-4-2?item=4783&cat=837&_m=d

I just discovered that when I export an OBJ out of the latest Daz along with the textures, the maps load right up on the object when I load it in Modeler. Used to have to apply them manually.

IMI
03-09-2009, 02:54 AM
I just discovered that when I export an OBJ out of the latest Daz along with the textures, the maps load right up on the object when I load it in Modeler. Used to have to apply them manually.

That's because LW now loads a .mtl file (if one is present in the same folder) along with the .OBJ file, and if the .mtl file has absolute paths to the texture locations, the textures will load along with the model. But .mtl files with only relative paths will cause a prompt for the texture location, since it knows the texture name but not the location. I'm sure you know all about how that works already, but not about what changed in LW's OBJ import.

You get that OBJ/MTL import by having the "OBJ ZBrush Mode" option UN-checked in the options panels.
Unfortunately, if you UN-check the new "OBJ ZBrush Mode" in the options for Layout or Modeler, while you'll load an OBJ file based on the .mtl information, you will lose all the point and poly group information. As you probably know, the DAZ figures already have all those vertex maps in the OBJ file, the point and poly groups for the body parts.

But if you select the "OBJ ZBrush Mode" for the OBJ import, you will get an OBJ file with all the vertex map data intact, but it won't read the .mtl file and thus, no textures will load.

Oddly enough, while NOT in "OBJ ZBrush Mode", if there's a .mtl file in the same folder, you will get all the surface assignments in an OBJ file, but if there's NO .mtl file available, an OBJ file will load completely missing all assigned surface data and the whole OBJ file will have only one surface called "obj_default_surface" (or something like that) and the luminosity and spec will be cranked way up. Strange, because the "standard" OBJ format is supposed to at least contain the surfaces, with or without a .mtl file. At least it doesn't "lose" the UV map.

Very strange. Just can't win, can't have it both ways.

BTW, the "new" OBJ ZBrush Mode is, as far as I can tell, essentially the same old OBJ import with a new name.

littlewaves
03-09-2009, 12:01 PM
C'mon folks, DAZ already.

Michael 4 and Victoria 4.2 are FREE.


They're pretty good figures but personally I find their vast polycount a little unwieldy.

Daz used to have low poly versions available but even they were fairly heavy.

But they are indeed free so worth a look