collisionID/shapeID/contactID & NewtonTreeCollisionEnd BUG

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collisionID/shapeID/contactID & NewtonTreeCollisionEnd BUG

Postby JernejL » Fri Oct 12, 2018 2:25 am

I'd like something a bit confused cleared up and document as i had some struggle understanding this, but now i think i understand majority of it.

Most of time, shapeID is defined as a int, and on 32 bit system this will be a 32 bit int.

In NewtonWorldRayFilterCallback it is called shapeHit, and is a 64 bit int (even in 32 bit lib).

From what i understand, this is standard "shapeID", but with different name (i tested this thoroughly): In NewtonTreeCollisionAddFace it is however named faceAttribute, but it's still the same piece of data (and 32 bit).

There is additionally a bug here - newton will optimize faces in NewtonTreeCollisionEndBuild and merge those with different shapeID/faceAttribute together, and destroy the shapeID data of specific part of the mesh when merging its polygons. I suggest that this is changed, so that it only merges faces with identical shapeID/faceAttribute.

The same data is is also named that way (but 64 bit) in NewtonCollisionCollide and NewtonCollisionCollideContinue

In NewtonWorldConvexCastReturnInfo struct it is named m_contactID (and 64 bit) - i think this is once again the ShapeID?

Could we just rename these parameters so they'd be all named same - i suggest we name them "ShapeUserID", and change it to all same type - i suggest it set to a 64 bit int, but not a pointer type, because the shapeid gets serialized and would be invalid after serialization if people put pointers into that field.
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