Tuesday, February 28, 2012

One year late

Ok I'm a bit late posting this one...
But if you've one day wondered about the macros _SECURE_SCL and _HAS_ITERATOR_DEBUGGING of MS STL then you're in for a treat!!

Bonus you get to learn a new undocumented CL switch! Thanks Microsoft!

#pragma detect_mismatch  :
This should never have had to be created. Don't conditionaly compile in or out members of your classes. Please, just don't.

Have a good one!

Saturday, June 18, 2011

Debugging python scripts for motion builder

Debugging in python can be very difficult. Well, in fact debugging in most interpreted languages can be difficult. And to be exact, the real problem comes from the lack of good debugging tools.
Most script programmers try to run the interpreter very often and to iterate a lot on their code. This is sufficient for most cases when scripts are quite straightforward. When things get complicated the need for a debugger arise.
Luckily, python provides a debugger : pdb. Knowing how to use it can be life saver !

Thursday, May 05, 2011

Linear wavelet

Last time I showed how I implemented the lifting scheme using haar prediction. This was the first example of our serie, and clearly the most simple one. The thing is that it's not very performant for what we want : approximating animation curves. The problem is that it's not continuous, I cannot encode smooth variaitions in the signal.
While linear interpolation doesn't really preserve smooth variations, it's still better than haar ! And it will be a good step before implementing other interpolation scheme to use in our implementation of the lifting scheme.

Tuesday, May 03, 2011

Haar wavelets

Last time I quickly posted the code I used to develop and test the different lifting scheme I showed you in an earlier post.
This time we'll talk about haar wavelets...

Saturday, April 30, 2011

wavelet tests

After reading a bit about wavelets and how to use the transform in order to compress animation data I decided to implement them (hence the screenshots I've uploaded in the first post).

I wanted to focus on the actual algorithm and not start writing hundreds of lines of code related to loading the animation file, displaying the curves, playback and GUI ... so I decided to write everything in python and have it running in motion builder. Ah... motion builder :)

This post will describe a bit of the building blocks I used to implement the 4 different wavelet algorithm I tried...

Thursday, April 28, 2011

wavelets ... some interesting reading

OK, I teased you, I've presented the big picture ... now is time to go deeper !

Monday, April 25, 2011

Wavelets ... what is that ?

Last post I talked about wavelets but didn't explain what it is nor what it's used for.
I'll make up for this in this post.