www.ssontech.com

[eldon]

Hi,

I tried to track points on a hand. This works well in SynthEyes.
Then I tried to import it in C4D. I adjusted the focal lenght and the field of view. I matched the scale. But it doesn't fit.

Here a simple example shot with an .lws export.

Perhaps somebody of you has an idea.

https://www.dropbox.com/s/uqjfzc75zct0dzm/Hand%20Tracking%20%282%29.rar

Thank you

eldon

[borgus]

hi eldon and welcome!

ok, just had a look at it. this won't perfectly work as an object track
since the points on the hand are not static. All markers on the hand
are moving to each other. You can try it, but there's no guarantee.
What you want in this case is to mocap all markers individually using
at least three calibrated cameras.

Cheers,

Seb.

[eldon]

Hey, thank you for your reply.

Can you explain me why this doesn't work?

I thought this would be simple. The points in synth eyes should only be at the same position in C4D.

I took this Tutorial as a basis: https://www.youtube.com/watch?v=tagyQuOZiA4&list=UU4zVeMH0For7MD4P3B9dfxQ&index=10&feature=plcp

Isn't it the same idea?

[borgus]

it's basically the same, but have a look at his face. There's almost no
expression, so that the points are regid. In the case of your hand you
can see that the points are moving to each other because the muscles of
your hand are moving (and the skin is stretching etc.). Because all
points are moving in a (slightly) different direction, syntheyes can't triangulate the correct postion is space. to get an accurate object track
you need at least 6-7 rigid points on differnet planes in depth. pls. also check out the manual for that.

-Seb.

[eldon]

Ok, you say if I will not move my fingers and keep my hand like a stone then it should work?

Compared to this: https://www.youtube.com/watch?v=iOmsnQy6X8I&feature=related

Or this: https://www.youtube.com/watch?v=C4XrnLrlu14&feature=relmfu

where they are only moving their hand but not stretching or bending it.

[borgus]

correct... the first one is probably using seed points...

[eldon]

Ok, thank you. Can you tell me something about the use of seed points. I read the parts in the manual, but I didn't get the real sense of it.

To bring it to the top. What do I have to do, to track the hand including finger movements? Every finger, or even better, every part of the finger a single object?

Or do I really have to use at least three cameras?
I mean, there are surely movies where a spider is walking over a hand. Will they use three cameras for this?

[borgus]

in the case of a spider walking over a hand you will need additional
cameras to capture the points from differnt agels. You would probably also
need some matchamation to animate a the geometry for the hand (depending on the shot and demands).

seed points or survay datas are useful when dealing with shots with little perspective (because of too less camera movement, nodal pans, long lenses etc. ) or when you need to fit your solve into a certain environment.

-Seb