[Bf-python] Bundled scripts that use python extensions?

[joeedh]

Jonathan Merritt wrote:

> Hi Everyone,
>
> I am currently working on a script that might be a good candidate for 
> a bundled script: camera calibration.  This is sometimes called 
> "camera matching" in a VFX context.  The idea is that by matching up 
> points in an image taken by a real camera to locations of virtual 
> points in 3D space, the camera position and orientation and its 
> internal parameters ("Lens", in the case of Blender), can be 
> determined.  The virtual camera can be placed at the same relative 
> spot in the virtual scene as the real camera occupied when the image 
> was taken.  This is extremely useful for accurate Blendering on 
> photos, image-based-modeling, etc.
>
> The particular algorithm I'm using for camera calibration was 
> developed by a guy called Roger Tsai and is quite complicated.  It 
> first involves using a linear process to approximate the set of camera 
> parameters, followed by a non-linear optimization by minimizing the 
> sum of squared errors of the calibration points in image space.  Put 
> simply, it would be *hell* to code in raw Python, and not exactly 
> straightforward even with the current Python numerical libraries that 
> are available.
>
> Fortunately, a C implementation is already available here:
>    http://www-2.cs.cmu.edu/afs/cs.cmu.edu/user/rgw/www/TsaiCode.html
> I have substantially modified the code from that website to create a 
> Python extension module (which wasn't so straightforward... try doing 
> a "grep -R exit *" and feel my pain... :-)  I am currently tidying up 
> this module prior to release, and adding in some decent test functions.
>
> I'm just wondering what the policy will be for bundled scripts that 
> require Python extension modules?  How will this work in a general case?

In this case, due to the coolness of what you are doing I suspect that 
within a month of you posting your script you may find it hardcoded into 
Blender, :).  Hm.  Ooh!  An idea!  Since bundled scripts are "bundled" 
their associated C modules could be built at blender-compile-time!  So, 
Willian, what do you think?

>
> Thanks,
>
> Jonathan Merritt.
>
> PS - Is there a bundled scripts discussion group yet?  I did go 
> looking (I promise) in the Wiki, but couldn't find one listed there.

http://projects.blender.org/mailman/listinfo/bf-scripts-dev

Getting to the general list list requires url editing, it's at 
http://projects.blender.org/mailman/listinfo/

joeedh