Dual-space Expansion for Estimating Penetration depth

So I have been implementing Dual-space Expansion for Estimating Penetration depth (DEEP) for a while now. In the past few days I put it to work and it sucked. The amount of frustration from doing Contact Manifold & Signed Distance Map and getting Trouble With The Projection kept piling up to this point, and this DEEP blow just pushed the frustration to an astronomical level. This morning I finally had a revelation that I might just need to go back to make box-box collision work instead of finding new algorithms that add more unmanageable complexity without any realistic benefit.

But here is the twist of the story. After all, the time I have invested in this effort will not be wasted. An innocent bug was accidentally found and DEEP w/ contact manifold code finally works!! It turns out the problem is when only four Contact are used for every contact that is happenning. Somehow I still cannot duplicate the performance of test_crash, but with careful tunning of the contact parameters, the collision of the boxes will show some physically believable behaviors. To me it has been a major progress considering how many frustrating hours I have spent on coding this. For example, erp=0.8 never works and neither without using maxvel to restraint the correcting contact velocity.

Now a new problem emerges: DEEPGeom will break HashSpace ...