[Bf-committers] Help with Matrix problem

[Casey Corn]

--- Alexander Ewering <blender at instinctive.de> wrote:

> 
> To better understand what the current problem is, take a look here:
> 
> http://pub.intrr.org/grouprot.png
> 
> On the left you can see two object Groups, grouped into a third
> Group (Group.003).
> 
> On the right, this group has been instanced and rotated by 45 deg.
> around the view axis.
> 
> The boundboxes shown there are *correct*, but highly 'unintuitive'.
> 
> I guess it would be a task for a real 3d math genius to find a way
> to construct a boundbox that is correct and at the same time
> reflects the rotation of the group object. :)

No genius required, you just need to know the proper terms. ;)

The bounding boxes shown in your picture are called "axis-aligned bounding
boxes."  Even though this link:

http://www.gamespp.com/algorithms/AdvancedCollisionDetectionTechniques2.html

is more for collision detection, it gives a nice overview of the different
bounding box types (scroll down a little).  I believe you are looking for
"oriented bounding boxes."

Hope this helps,
Casey


		
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