Assembly: Joint creation presolve: move part2 rather than part1 when both are unconnected.

Author: PaddleStroke

src/Mod/Assembly/JointObject.py

@@ -706,43 +706,43 @@ def preSolve(self, joint, savePlc=True):
             part2Connected = assembly.isPartConnected(part2)
             joint.Activated = True
         else:
-            part1Connected = False
-            part2Connected = True
+            part1Connected = True
+            part2Connected = False
 
-        if not part2Connected:
+        if not part1Connected:
             if savePlc:
-                self.partMovedByPresolved = part2
-                self.presolveBackupPlc = part2.Placement
+                self.partMovedByPresolved = part1
+                self.presolveBackupPlc = part1.Placement
 
-            globalJcsPlc1 = UtilsAssembly.getJcsGlobalPlc(joint.Placement1, joint.Reference1)
-            jcsPlc2 = UtilsAssembly.getJcsPlcRelativeToPart(
-                assembly, joint.Placement2, joint.Reference2
+            globalJcsPlc2 = UtilsAssembly.getJcsGlobalPlc(joint.Placement2, joint.Reference2)
+            jcsPlc1 = UtilsAssembly.getJcsPlcRelativeToPart(
+                assembly, joint.Placement1, joint.Reference1
             )
             if not sameDir:
-                jcsPlc2 = UtilsAssembly.flipPlacement(jcsPlc2)
+                jcsPlc1 = UtilsAssembly.flipPlacement(jcsPlc1)
 
             # For link groups and sub-assemblies we have to take into account
             # the parent placement (ie the linkgroup plc) as the linkgroup is not the moving part
             # But instead of doing as follow, we rather enforce identity placement for linkgroups.
             # parentPlc = UtilsAssembly.getParentPlacementIfNeeded(part2)
             # part2.Placement = globalJcsPlc1 * jcsPlc2.inverse() * parentPlc.inverse()
 
-            part2.Placement = globalJcsPlc1 * jcsPlc2.inverse()
+            part1.Placement = globalJcsPlc2 * jcsPlc1.inverse()
             return True
 
-        elif not part1Connected:
+        elif not part2Connected:
             if savePlc:
-                self.partMovedByPresolved = part1
-                self.presolveBackupPlc = part1.Placement
+                self.partMovedByPresolved = part2
+                self.presolveBackupPlc = part2.Placement
 
-            globalJcsPlc2 = UtilsAssembly.getJcsGlobalPlc(joint.Placement2, joint.Reference2)
-            jcsPlc1 = UtilsAssembly.getJcsPlcRelativeToPart(
-                assembly, joint.Placement1, joint.Reference1
+            globalJcsPlc1 = UtilsAssembly.getJcsGlobalPlc(joint.Placement1, joint.Reference1)
+            jcsPlc2 = UtilsAssembly.getJcsPlcRelativeToPart(
+                assembly, joint.Placement2, joint.Reference2
             )
             if not sameDir:
-                jcsPlc1 = UtilsAssembly.flipPlacement(jcsPlc1)
+                jcsPlc2 = UtilsAssembly.flipPlacement(jcsPlc2)
 
-            part1.Placement = globalJcsPlc2 * jcsPlc1.inverse()
+            part2.Placement = globalJcsPlc1 * jcsPlc2.inverse()
             return True
         return False