[Bf-committers] Motion tracking project

[Sergey Sharybin]

HI,

Not actually sure what your proposal is, it depends actually.

We've got some basis in libmv already (AFAIR, we've got n-view intersection
code already, but could remember something wrong by hand). So you'll likely
need to just write n-view bundle adjuster, which is not so difficult i
think.

But here's one "BUT" -- this will work for rigid objects only i think. Not
sure how much difficult it'll be to reconstruct non-rigid objects.

So, if you want to write a command-line tool which will do n-view rigid
reconstruction it's much easier to do from libmv side. I'm keeping own
branch of libmv in github which i'm keeping up-to-date with changes made in
blender, and also doing some WIP tests there. So you'll probably want to
check on https://github.com/Nazg-Gul/libmv

If you're thinking about integrating such functionality into blender, it
depends. There're some things personally i consider useful (someone could
disagree tho:) -- like scene reconstruction using main and witness camera
(not so much complicated/expensive to use), will also move us a bit further
to motion capture. Also, if you'll want blender to capture something
realtime it'll be the most difficult thing to match our pipeline, so
probably it'll be some combination of changes in libmv and python script
for blender?


On Wed, Apr 17, 2013 at 1:02 AM, Akhil Verghese <akhilcherian at gmail.com>wrote:

> Hi Sergey,
>
> I have a reasonable amount of experience with motion tracking. From my
> robotics projects and, more recently, with my project on gait analysis. I
> was a little overwhelmed with the project description though. Were the
> individual projects mentioned intended as one large project or as
> suggestions for separate projects? I have a little experience relating to
> the lens estimation and variable focal length projects and a considerable
> amount of experience with multi-camera reconstructions, but implementing
> all eight projects listed seems like a lot in a summer.
>
> My own suggestions for this project are based on the needs I've felt while
> working on my current assignment. The lab I'm volunteering at uses 8
> cameras spaced around a room to determine the x, y and z coordinates of 15
> LEDs attached to different points of a subjects legs. The data is stored as
> the subject moves and my program recreates the motion on my screen. It also
> calculates the internal forces involved and re-simulates the motion, given
> certain additional criteria. I'm presenting my software on Monday to the
> department, and I can send a youtube link with my application.
>
> The method of reconstructing the motion was pretty basic. The cameras
> generated the coordinates in the form:
> <frame number> <LED/reference point number> <x> <y> <z> which seemed like a
> pretty obvious format to me. I was surprised to find that I couldn't find a
> software that directly took data of this form or any similar form and
> reconstructed the motion. If one could design a 3d object (even a humanoid)
> and specifically assign the reference points (say a marker on your right
> wrist) to distinct points on the objects (the right wrist of the humanoid)
> in an open source application, I think it would save on a lot of tedious
> coding and have numerous applications (maybe even for virtual games). I'm
> not sure if I've described this clearly. Please let me know if it needs
> further explanation or if you think it could be incorporated into the
> motion tracking project.
>
> Thanks.
>
>
> On Tue, Apr 16, 2013 at 11:37 PM, Sergey Sharybin <sergey.vfx at gmail.com
> >wrote:
>
> > Hi,
> >
> > Currently this is mainly me who're working on motion tracker in blender.
> > There's also Keir Mierle who wrote libmv library we're using for motion
> > tracking, and who also improving tracker while not busy with his real
> job.
> >
> > Feel free to contact us, or we could simply discuss your ideas here
> (think
> > Keir is also subscribed to this list).
> >
> >
> > On Tue, Apr 16, 2013 at 11:45 PM, Akhil Verghese <akhilcherian at gmail.com
> > >wrote:
> >
> > > Hi,
> > >
> > > I'm currently doing a project with a bioengineering lab in India,
> > tracking
> > > and recreating human gait, using inverse kinematics to calculate the
> > > internal forces and writing the simulation program to display the gait
> > > under varying conditions. I have a bunch of ideas for the motion
> tracking
> > > project, and I was wondering who I should get in touch with. During my
> > > current project, I wrote the entire code from scratch with java, but I
> > did
> > > look around for a good software that combined motion tracking along
> with
> > > physics generators and didn't find one that fit my needs. I'd love to
> > help
> > > with the motion tracking, since I've spent the last 4 months doing
> > > precisely that. I have a video that demonstrates my software.
> > >
> > > Looking forward to hearing from you and discussing my ideas.
> > >
> > > Thanks
> > >
> > > --
> > > Akhil Cherian Verghese
> > > Under Graduate Student
> > > Physics and Civil Engineering
> > > BITS Pilani
> > > +91-95294-45757
> > > +91-99307-88323
> > > _______________________________________________
> > > Bf-committers mailing list
> > > Bf-committers at blender.org
> > > http://lists.blender.org/mailman/listinfo/bf-committers
> > >
> >
> >
> >
> > --
> > With best regards, Sergey Sharybin
> > _______________________________________________
> > Bf-committers mailing list
> > Bf-committers at blender.org
> > http://lists.blender.org/mailman/listinfo/bf-committers
> >
>
>
>
> --
> Akhil Cherian Verghese
> Under Graduate Student
> Physics and Civil Engineering
> BITS Pilani
> +91-95294-45757
> +91-99307-88323
> _______________________________________________
> Bf-committers mailing list
> Bf-committers at blender.org
> http://lists.blender.org/mailman/listinfo/bf-committers
>



-- 
With best regards, Sergey Sharybin