> Actually, it's not what I needed. I'll explain what I'm doing:
>
> I'm making a space shooter, but I want to model motion properly
> according to the laws of physics, or at least that much which makes it
> computationally feasible. Thus, the ****ps and smaller craft need to
> have certain physical qualities and quantities defined for them:
> volume, density, center of mass, center of percussion, moments of
> inertia, etc.
>
> Because the ****ps will be complex and concave, simply summing the
> volume of the pyramids defined by the triangles won't work. I'll need
> to sample discreet "points." I've spent a significant amount of time
> contemplating the "ifs" so I can do this right. I tried to conceive
> of a possibility of where the sampling box would be fooled into
> thinking it's inside the object, when it really wasn't, or outside
> when it was not. The object will have a AABB the defines the min and
> max extents of testing, so infinity is not an issue.
>
> Thanks for the point toward BSP trees, though. Eventually, I'll sit
> down and study them hard. I understand the concept of trees, but
> could never grasp the implementation.
Oh, ok. Then your method seems to be a good choice. But I still do not
see the point in tracing in two directions. Beginning from the point you
want to test, just trace a single ray into an arbitrary direction. Then
the inclusion of the point in the object is determined by the first
thing you hit:
1) You hit the bound box first: The test point is outside the object
2) You hit a triangle facing towards your test point: You are outside
3) You hit a triangle facing away from your test point: You are inside
A binary space partitioning tree could speed up the line tracing
significantly, but since calculation of volume sounds like something
being done once, calculation time seems rather unim****tant.
It might come in handy when you have to calculate collisions in real
time though.
Also notice that a BSP-tree will allow you to decompose your object into
convex pieces, which in turn might allow you to decompose them into
pyramids and sum their volume.
But tracing lines will by far be the most simple approach.
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