3D Physics Rework, Other Stuff

-=-=-=-=-=-=-=-=-=-=-=-=-=-

3D Physics:
-Fixed "Bounce" parameter in 3D
-Fixed bug affecting Area (sometims it would not detect properly)
-Vehicle Body has seen heavy work
-Added Query API for doing space queries in 3D. Needs some docs though.
-Added JOINTS! Adapted Bullet Joints: and created easy gizmos for setting them up:
   -PinJoint
   -HingeJoint (with motor)
   -SliderJoint
   -ConeTwistJoint
   -Generic6DOFJoint
-Added OBJECT PICKING! based on the new query API. Any physics object now (Area or Body) has the following signals and virtual functions:
    -input_event (mouse or multitouch input over the body)
    -mouse_enter (mouse entered the body area)
    -mouse_exit (mouse exited body area)
   For Area it needs to be activated manually, as it isn't by default (ray goes thru).

Other:

-Begun working on Windows 8 (RT) port. Compiles but does not work yet.
-Added TheoraPlayer library for improved to-texture and portable video support.
-Fixed a few bugs in the renderer, collada importer, collada exporter, etc.

io_scene_dae/export_dae.py

@@ -317,14 +317,14 @@ class DaeExporter:
 
 	def export_mesh(self,node,armature=None):
 
+		if (node.data in self.mesh_cache):
+			return self.mesh_cache[mesh]
+
 		if (len(node.modifiers) and self.config["use_mesh_modifiers"]):
 			mesh=node.to_mesh(self.scene,True,"RENDER") #is this allright?
 		else:
 			mesh=node.data
 
-		if (mesh in self.mesh_cache):
-			return self.mesh_cache[mesh]
-
 		mesh.update(calc_tessface=True)
 		vertices=[]
 		vertex_map={}
@@ -519,7 +519,7 @@ class DaeExporter:
 		meshdata={}
 		meshdata["id"]=meshid
 		meshdata["material_assign"]=mat_assign
-		self.mesh_cache[mesh]=meshdata
+		self.mesh_cache[node.data]=meshdata
 
 
 		# Export armature data (if armature exists)
@@ -1094,7 +1094,14 @@ class DaeExporter:
 						mtx = posebone.matrix.copy()
 						if (bone.parent):
 							parent_posebone=node.pose.bones[bone.parent.name]
-							mtx = parent_posebone.matrix.inverted() * mtx
+							parent_invisible=False
+
+							for i in range(3):
+								if (parent_posebone.scale[i]==0.0):
+								    parent_invisible=True
+
+							if (not parent_invisible):
+								mtx = parent_posebone.matrix.inverted() * mtx
 
 
 						xform_cache[bone_name].append( (key,mtx) )