improved robustness of penetrations involving triangles and boxes, by adding their 'preferred' penetration directions.

added wireframe/solid mode for meshes
updated solid penetration depth solver (comparison in Extras)

src/BulletCollision/CollisionShapes/btBoxShape.h

@@ -255,6 +255,37 @@ public:
 		return "Box";
 	}
 
+	virtual int		getNumPreferredPenetrationDirections() const
+	{
+		return 6;
+	}
+	
+	virtual void	getPreferredPenetrationDirection(int index, btVector3& penetrationVector) const
+	{
+		switch (index)
+		{
+		case 0:
+			penetrationVector.setValue(1.f,0.f,0.f);
+			break;
+		case 1:
+			penetrationVector.setValue(-1.f,0.f,0.f);
+			break;
+		case 2:
+			penetrationVector.setValue(0.f,1.f,0.f);
+			break;
+		case 3:
+			penetrationVector.setValue(0.f,-1.f,0.f);
+			break;
+		case 4:
+			penetrationVector.setValue(0.f,0.f,1.f);
+			break;
+		case 5:
+			penetrationVector.setValue(0.f,0.f,-1.f);
+			break;
+		default:
+			assert(0);
+		}
+	}
 
 };
 

src/BulletCollision/CollisionShapes/btConvexShape.h

@@ -26,7 +26,7 @@ subject to the following restrictions:
 
 //todo: get rid of this btConvexCastResult thing!
 struct btConvexCastResult;
-
+#define MAX_PREFERRED_PENETRATION_DIRECTIONS 10
 
 /// btConvexShape is an abstract shape interface.
 /// The explicit part provides plane-equations, the implicit part provides GetClosestPoint interface.
@@ -84,6 +84,17 @@ public:
 		return m_collisionMargin;
 	}
 
+	virtual int		getNumPreferredPenetrationDirections() const
+	{
+		return 0;
+	}
+	
+	virtual void	getPreferredPenetrationDirection(int index, btVector3& penetrationVector) const
+	{
+		assert(0);
+	}
+
+
 
 };
 

src/BulletCollision/CollisionShapes/btTriangleShape.h

@@ -157,6 +157,18 @@ public:
 			return "Triangle";
 		}
 
+		virtual int		getNumPreferredPenetrationDirections() const
+		{
+			return 2;
+		}
+		
+		virtual void	getPreferredPenetrationDirection(int index, btVector3& penetrationVector) const
+		{
+			calcNormal(penetrationVector);
+			if (index)
+				penetrationVector *= -1.f;
+		}
+
 
 };