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fbs7
03-Aug-08, 17:25
Hello there,

In Poser, you can build a model made of separate meshes (head, neck, torso, arms, etc...), which are joined together through seams. The seams make the final model look smooth, so there is no visible transition between the meshes, which remain separate.

Any idea how to do that in Blender? It would very useful, as the examples below:

(a) In blender the skin of a human model is a single mesh, and that is really a bugger for adding softbodies -- the entire skin becomes a softbody but 99% of the vertices have a weight of 0, while say the belly alone has a non-zero weight. Simulation gets very slow, as it calculates a lot of vertices for nothing (weight 0). If I could model the belly as a separate mesh with a seam with to the rest of the body, that would make simulation much faster.

(b) Also, if I could model say the head as a separate mesh, then I could easily swap heads between different models. As it stands I have to delete the head, paste the other one and then manually build the edges between the new head and the rest of the model.

(c) Finally, Blender keys the entire mesh. It doesn't make much sense to me to key 30,000 vertices just to blink the eyes. That seems to consume a lot of memory. If I could model the region around the eyes as a separate mesh, then I could key only those guys.

Any advise is appreciated. I may be off with the question about seams, as perhaps the problems above are resolved in a different way in Poser without having to use mesh seams -- if so, I'd appreciate to learn how to resolve these, Poser-style.

Thanks for reading! :D
fbs7

Craig Jones
03-Aug-08, 20:43
In Blender, you can use what is called a 'vert group' to split a mesh into parts to be recalled later for applying separate materials to, as separate groups allow different applications - several modifiers and particle systems you will notice have spaces fro referencing these vert groups.

I don't know what you mean by modeling the eyes to animate - you can use shape keys or bone rigging to animate the eye lids, etc. You would be keying the position of the sliders for the interpolation of the shape key changes, or the position of the bones/rig for the animation. I haven't had a problem with memory usage on simple actions or movements, but maybe your mesh is much greater in size.

Also, technically you could model the head as a separate object, and parent it to the body or armature so that you could have it stay in the position you want.

I would check out the wiki pages on parenting and vert groups and see if that helps anything.

Orinoco
03-Aug-08, 21:12
In Blender you make the mesh look smooth by connecting it. Blender isn't Poser. Meshes tend to be lighter than Poser meshes, the subsurf modifier allows a few vertices to appear as if there are many more verts than Blender shape keys or softbodies have to keep track of.

But Blender isn't Poser. Trying to get Blender to do things "Poser-style" is setting yourself up for frustration.

If you are concerned about shape keys being too slow, don't use them, use armatures, or a deform cage.

If your heads all connect with the neck at the same verts, adding a new head is a simple matter of putting the head into the scene, making the body and head a single object, selecting all verts and removing doubles.

Seams in Blender are used to determine which faces in a UV layout don't have to be connected. They don't separate the mesh into pieces for separate calculation by subsurf, softbody, smoothing, or other functions.

musk
04-Aug-08, 02:31
TO add to what Orinoco said. The Blender way of constraining certain simulations to parts of a mesh are vertexgroups.

bjornmose
04-Aug-08, 04:11
...
(a) In blender the skin of a human model is a single mesh, and that is really a bugger for adding softbodies -- the entire skin becomes a softbody but 99% of the vertices have a weight of 0, while say the belly alone has a non-zero weight. Simulation gets very slow, as it calculates a lot of vertices for nothing (weight 0). If I could model the belly as a separate mesh with a seam with to the rest of the body, that would make simulation much faster.
...
Thanks for reading! :D
fbs7

No the other way around,




#define SOFTGOALSNAP 0.999f
...

later


if(bp->goal < SOFTGOALSNAP){ /* ommit this bp when it snaps */
...


So simply paint the parts you don't want do be handled by the soft body engine with goal 1.0
BM

fbs7
07-Aug-08, 14:09
Appreciate all the answers up so far, thanks for much for them.
So, I can create a vertex group and simulate only that vertex group, right? That seems to be perfect for my bouncing belly thing.
The idea of having common vertices between the head the the neck, and then removing duplicates to join them, seems to solve the scenario of switching heads (and body parts) around. Good idea :)
Now, can you also a key shape for a vertex group only? Or do you shape the entire mesh?
Thanks again :evilgrin:
fbs

Craig Jones
07-Aug-08, 14:55
You can create a shape key for the entire object, but select only the mesh (vertex group) that you want to make the change to.

Orinoco
07-Aug-08, 15:17
You can't isolate the shape key from the rest of the mesh by using vertex groups. Changes to the mesh will mess up the shape keys. If the change doesn't affect any moving parts, the "Propagate to all shapes" tool can allow mesh changes post shape key making, but it's really best to finalize the mesh topography before starting shape keys.