Re: Pointer for Cage Deformer Logic/Implementation

2013-12-13 Thread Alok Gandhi
That's great Ahmidou, looking forward to it. Sent from my iPhone On Dec 13, 2013, at 2:27 AM, Ahmidou Lyazidi ahmidou@gmail.com wrote: The problem with mean value coordinates is that they're negative with concave cages, and harmonic coordinates more complex and slower to generate. I

Re: Pointer for Cage Deformer Logic/Implementation

2013-12-12 Thread Alok Gandhi
Thanks Ben. That is some good info. I was thinking more along implementing the Harmonic Coordinates approach. I think Pixar had some papers on it. Sent from my iPhone On Dec 11, 2013, at 10:50 PM, Ben Houston b...@exocortex.com wrote: My knowledge is out of date, but off the top of my

Re: Pointer for Cage Deformer Logic/Implementation

2013-12-12 Thread Ben Houston
I guess you are referring to this... http://graphics.pixar.com/library/HarmonicCoordinates/paper.pdf The scan conversion bit with the laplacian solver seems like a lot of work. There is the idea of mean value coordinate systems which may allow for a smooth interpolant across the arbitrary

Re: Pointer for Cage Deformer Logic/Implementation

2013-12-12 Thread Ben Houston
Turns out mean value coordinates on closed polygon meshes to do deformation was already done: http://www.cs.rice.edu/~jwarren/papers/meanvalue.pdf -ben On Thu, Dec 12, 2013 at 9:45 AM, Ben Houston b...@exocortex.com wrote: I guess you are referring to this...

Re: Pointer for Cage Deformer Logic/Implementation

2013-12-12 Thread Ahmidou Lyazidi
The problem with mean value coordinates is that they're negative with concave cages, and harmonic coordinates more complex and slower to generate. I already implemented this paper in ICE: http://www.wisdom.weizmann.ac.il/~ylipman/pmvc/pmvc.htm The result is pretty closed to harmonic coordinates,

Pointer for Cage Deformer Logic/Implementation

2013-12-11 Thread Alok Gandhi
Hi All, Very soon, I am starting on my own generic custom cage deformer. A mix of C++/Cython/Python. I am thinking of implementing fast calculations on barycentric coordinates with affine transformations. I have some good papers (in my treasure trove but haven't checked it yet). Anyone suggest

Re: Pointer for Cage Deformer Logic/Implementation

2013-12-11 Thread Ben Houston
My knowledge is out of date, but off the top of my head Cage deformers are often written using a cubic interpolant rather than affine ones. If you use a grid cage you can use Bezier Volumes, which are just a generalization of https://en.wikipedia.org/wiki/B%C3%A9zier_surface. If you are