[Bf-committers] GSoC 201 - Automatic Skeleton Extraction

[Alexander Pinzon Fernandez]

Hello, Thank you all for your comments.

First of all I want to make some clarifications::


   - This method does not use any template or skeleton model.
   - This method ensures that the skeleton generated depends only on the
   features of the mesh (size, shape, segments, curvature, etc).
   - This is not a method for a pose detection..
   - Blenrig is only for bipeds, the proposed method is for any model.
   - Skeleton extraction based on mesh contraction has better results that
   method based on reeb graphs, see page 8
   http://visgraph.cse.ust.hk/projects/skeleton/skeleton_sig08.pdf.


I wish to highlight some advantages of the implementation of this method

   - The method will allow novice users to animate any polygon mesh as
   people, animals or inorganic objects.
   - The method can be a starting point for an experienced designer.
   Because this method automatically segments the mesh. Generating the vertex
   groups for each segment found.
   - The method allows to obtain the skeleton of all mesh well defined.
   People, animals, (inorganic elements such as tables, chairs, etc.).


I should also mention that create the skeleton of an octopus, or other such
complex element can be simple but it is a tedious task because you must
first create the skeleton, adjusting each bone in the body, and the mesh
should be segmented into parts, and linking every part of the skeleton with
a bone with this project is to perform all these steps automatically.

The proposed method has been widely accepted in the community of computer
graphics, for its robustness against noise, its simplicity in
implementation and because it is resistant to isometric changes.

You can see a video showing the method, and some images of skeletons
obtained with this method.

http://www.youtube.com/watch?v=-H7n59YQCRM
http://graphics.csie.ncku.edu.tw/Skeleton/index.files/image004.gif
http://visgraph.cse.ust.hk/projects/skeleton/index.files/image012.jpg

Att.
Alexander Pinzon Fernandez
[image: Imágenes integradas 3]

[image: Imágenes integradas 2]


2013/4/26 Patrick Shirkey <pshirkey at boosthardware.com>

>
> On Fri, April 26, 2013 5:54 am, Juan Pablo Bouza wrote:
> > If I'm not wrong, there where some guys in the Blender Conference that
> had
> > developed a system where the program automatically detected the human
> > shape, and was able to target a bvh rig to it. The name is Christophe
> > POIREL, maybe you could get in contact with him and see if you can use
> any
> > of his work or ideas.
> >
> > The way I see it (I'm the creator of BlenRig auto-rigging, now my site is
> > down :p ) is that it would be cool no to just be able to generate a
> simple
> > armature, but to develop a system that would also be able to retarget
> > custom rigs. But well, a tool like that might be too specific, and maybe
> > it wouldn't be worth the effort.
> >
> > Anyway, Zanqdo never used BlenRig, that's why he says that auto-rigging
> > systems are not good enough for him... :p
> >
>
> I have used BlenRig and MakeHuman. They have two different methods for
> applying a rig. I'm not sure of the specific method used in MH but they
> have figured out how to apply various rigs to meshes more accurately than
> my results with BlenRig.
>
> You might also want to look there for some ideas.
>
> What is currently missing is a way to transfer anims from one model with a
> different scale to another model. I have made various tests with the
> xonotic rig from MH and found that the official xonotic rigs are approx
> 2.5 times larger than the MH version and that causes stretching along the
> z-axis.
>
> http://iguanapro.com/cube/mh4-2.png
> http://iguanapro.com/cube/mh4-3.png
> http://iguanapro.com/cube/mh4-4.png
> http://iguanapro.com/cube/mh4-5.png
>
> A simple method for merging the anims from different models with the same
> rig without stretching the mesh would be very useful. Then we could rig
> the model with an arbitrary rig using the MH method and apply the anims
> from other existing models with the same rig easily and quickly. My tests
> so far have required me to export the rigs and anims from Blender in iqe
> format and merge them manually to get the anims from one model to another
> but that results in stretching.
>
> MH already have a MakeRig plugin for blender that allows exporting a rig
> bvh for use with their internal format and my plan is to ad an iqe/iqm
> exporter to MH too which is one way to avoid stretching/scaling issues.
>
>
>
> --
> Patrick Shirkey
> Boost Hardware Ltd
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