Art Vandelay

Interesting drag and drop issue

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I took the drag and drop demo and added collisions to it. Basically that means that in onPointerMove:

  1. I move the mesh
  2. I do mesh.computeWorldMatrix
  3. I check for an intersection of the mesh with every other mesh and if I discover one I move the mesh back

Everything works fine and the meshes generally don't "go through" each other. However, if I drag a mesh fast enough it will slightly intersect with another mesh before actually being stopped by it. I can't understand why this is happening.

Any ideas?

Thanks! :)

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Hi.  I'll help with the PG.

Notice lines 102-104.  During drag, if green box intersects blue box, quit onPointerMoving.

Now... drag blue box... at high velocity... into side of green box.  They overlap.  And they are stuck in intersect-state, so, no more onPointerMove happens ever again (without the help of a crowbar)  :)

Hope this helps.  Hey, what if we invented mesh.deIntersect()... called from the collide observer.  It does a careful analysis of bounding boxes, and determines WHICH DIRECTION to start moving the .source... to make it eventually de-intersect (and clear the intersect state).  There could also be a "speed" setting.  Wow!  Essentially, animateFromIntersect(). 

But yeah, high-horsepower dragging is not for children.  Penetration can happen.  :o

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