Real-Time Physics Simulation Forum

I'm reading Bullet source code.The function dBoxBox2() is complicated to me,who can explain it to me!How to get peneration depth,contact point?
The Function dBoxBox2() is in btBoxBoxDetector.cpp

I got vertex face contact.But edge-edge contact is diffult.I 'm think why we don't use quadratic programming(David Eberly use it)to get distance between two rigid box.

I can't undetstand function dLineClosestApproach() in btBoxboxdetector.cpp.There is not explain.Who can help me!

(necro this old thread)

I am curious, so I begin to dig into the source (https://github.com/bulletphysics/bullet ... tector.cpp).

First, it uses separation theorem.

Then, it selects the direction (in separation theorem) that yield the least overlapping distance.

After that, it projects a face of body A, and a face of body B - using the direction as Normal. (and B A vice versa)
There might be 6*6 = 36 cases. I am not sure.
Using the projection result, It calls "intersectRectQuad2()" to check whether an overlapping occur.
That would be enough for vertex case.

For the edge vs edge, I believe the same procedure could be used : just use Normal = edge from A (cross) edge from B.
I didn't check it yet.