box-box intersection test

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Original post by remdul What is the best (simplest/fastest) way to do object aligned box-box intersection test? Should I do a plane-plane intersection for each 6-sides, and then check whether that line segment lies within the box dimensions, or do a line-plane test for each edge? Any other way to get the intersection points?

Separating Axis Theorem, currently being discussed here and here. Also try geometrictools.com for documentation and sample code.

Thanks, I've already read some of that but I doubt I can understand any of that.

Is it possible get correct results with the methods I mentioned?

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Original post by remdul Thanks, I've already read some of that but I doubt I can understand any of that. Is it possible get correct results with the methods I mentioned?

You could brute force it with point-containment and edge-face tests. I suppose it might be easier conceptually, but it'll be much slower and probably less robust as well. Also, it may be more difficult to extract meaningful contact info (depending on what you need such info for), and it'll be harder to derive a swept version of the test (if you need it).

Personally, I'd just buckle down and implement the SAT. There are plenty of good references available.

Assuming that the position of the box is defined by the center of the box.
if
|x₁ - x₂| <= width₁ / 2 plus width₂ / 2
and
|y₁ - y₂| <= height₁ / 2 plus height₂ / 2
and
|z₁ - z₂| <= depth₁ / 2 plus depth₂ / 2

then the boxes intercect.

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Original post by SuperNerd Assuming that the position of the box is defined by the center of the box. if |x1 - x2| <= width1 / 2 plus width2 / 2 and |y1 - y2| <= height1 / 2 plus height2 / 2 and |z1 - z2| <= depth1 / 2 plus depth2 / 2 then the boxes intercect.

That's an AABB test. Although it wasn't mentioned specifically, I believe the OP is looking for an OBB test.

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Original post by jyk That's an AABB test. Although it wasn't mentioned specifically, I believe the OP is looking for an OBB test.

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Original post by remdul object aligned box-box

Thanks jyk, I'll give SAT another try. All I need is the penetration depth and a least one contact point.