allow BSplineSurfaces to be used as planes

InitGui.py

@@ -26,7 +26,7 @@
 __title__ = 'A2plus assembly Workbench - InitGui file'
 __author__ = 'kbwbe'
 
-A2P_VERSION = 'V0.4.15'
+A2P_VERSION = 'V0.4.16'
 
 
 

a2p_constraints.py

@@ -223,7 +223,7 @@ def calcInitialValues(self):
         c = self.constraintObject
         point = getPos(self.ob1, c.SubElement1)
         plane = getObjectFaceFromName(self.ob2, c.SubElement2)
-        planeNormal = plane.Surface.Axis
+        planeNormal = a2plib.getPlaneNormal(plane.Surface)
         planePos = getPos(self.ob2, c.SubElement2)
         #
         # calculate recent offset...
@@ -463,8 +463,10 @@ def calcInitialValues(self):
         c = self.constraintObject
         plane1 = getObjectFaceFromName(self.ob1, c.SubElement1)
         plane2 = getObjectFaceFromName(self.ob2, c.SubElement2)
-        normal1 = plane1.Surface.Axis
-        normal2 = plane2.Surface.Axis
+
+        normal1 = a2plib.getPlaneNormal(plane1.Surface)
+        normal2 = a2plib.getPlaneNormal(plane2.Surface)
+
         angle = math.degrees(normal1.getAngle(normal2))
         if angle <= 90.0:
             self.direction = "aligned"
@@ -513,8 +515,10 @@ def calcInitialValues(self):
         c = self.constraintObject
         plane1 = getObjectFaceFromName(self.ob1, c.SubElement1)
         plane2 = getObjectFaceFromName(self.ob2, c.SubElement2)
-        normal1 = plane1.Surface.Axis
-        normal2 = plane2.Surface.Axis
+
+        normal1 = a2plib.getPlaneNormal(plane1.Surface)
+        normal2 = a2plib.getPlaneNormal(plane2.Surface)
+
         angle = math.degrees(normal1.getAngle(normal2))
         if angle <= 90.0:
             self.direction = "aligned"
@@ -561,8 +565,8 @@ def __init__(self,selection):
     def calcInitialValues(self):
         plane1 = getObjectFaceFromName(self.ob1, self.sub1)
         plane2 = getObjectFaceFromName(self.ob2, self.sub2)
-        normal1 = plane1.Surface.Axis
-        normal2 = plane2.Surface.Axis
+        normal1 = a2plib.getPlaneNormal(plane1.Surface)
+        normal2 = a2plib.getPlaneNormal(plane2.Surface)
         self.angle = math.degrees(normal2.getAngle(normal1))
 
     @staticmethod
@@ -661,8 +665,8 @@ def calcInitialValues(self):
         #plane2 = getObjectFaceFromName(self.ob2, self.sub2)
         CoM1 = plane1.CenterOfMass
         CoM2 = plane2.CenterOfMass
-        axis1 = plane1.Surface.Axis
-        axis2 = plane2.Surface.Axis
+        axis1 = a2plib.getPlaneNormal(plane1.Surface)
+        axis2 = a2plib.getPlaneNormal(plane2.Surface)
         angle = math.degrees(axis1.getAngle(axis2))
         if angle <= 90.0:
             self.direction = "aligned"

a2p_dependencies.py

@@ -192,7 +192,7 @@ def Create(doc, constraint, solver, rigid1, rigid2):
             plane2 = getObjectFaceFromName(ob2, c.SubElement2)
             dep2.refPoint = plane2.Faces[0].BoundBox.Center
 
-            normal2 = plane2.Surface.Axis
+            normal2 = a2plib.getPlaneNormal(plane2.Surface)
             #shift refPoint of plane by offset
             try:
                 offs = c.offset
@@ -239,8 +239,9 @@ def Create(doc, constraint, solver, rigid1, rigid2):
             dep1.refPoint = plane1.Faces[0].BoundBox.Center
             dep2.refPoint = plane2.Faces[0].BoundBox.Center
 
-            normal1 = plane1.Surface.Axis
-            normal2 = plane2.Surface.Axis
+            normal1 = a2plib.getPlaneNormal(plane1.Surface)
+            normal2 = a2plib.getPlaneNormal(plane2.Surface)
+
             if dep2.direction == "opposed":
                 normal2.multiply(-1.0)
             dep1.refAxisEnd = dep1.refPoint.add(normal1)
@@ -257,8 +258,8 @@ def Create(doc, constraint, solver, rigid1, rigid2):
             dep1.refPoint = plane1.Faces[0].BoundBox.Center
             dep2.refPoint = plane2.Faces[0].BoundBox.Center
 
-            normal1 = plane1.Surface.Axis
-            normal2 = plane2.Surface.Axis
+            normal1 = a2plib.getPlaneNormal(plane1.Surface)
+            normal2 = a2plib.getPlaneNormal(plane2.Surface)
             dep1.refAxisEnd = dep1.refPoint.add(normal1)
             dep2.refAxisEnd = dep2.refPoint.add(normal2)
 
@@ -273,8 +274,8 @@ def Create(doc, constraint, solver, rigid1, rigid2):
             dep1.refPoint = plane1.Faces[0].BoundBox.Center
             dep2.refPoint = plane2.Faces[0].BoundBox.Center
 
-            normal1 = plane1.Surface.Axis
-            normal2 = plane2.Surface.Axis
+            normal1 = a2plib.getPlaneNormal(plane1.Surface)
+            normal2 = a2plib.getPlaneNormal(plane2.Surface)
             if dep2.direction == "opposed":
                 normal2.multiply(-1.0)
             dep1.refAxisEnd = dep1.refPoint.add(normal1)
@@ -336,7 +337,7 @@ def Create(doc, constraint, solver, rigid1, rigid2):
             axis1Normalized.normalize()
             dep1.refAxisEnd = dep1.refPoint.add(axis1Normalized)
 
-            normal2 = plane2.Surface.Axis
+            normal2 = a2plib.getPlaneNormal(plane2.Surface)
             dep2.refAxisEnd = dep2.refPoint.add(normal2)
 
         elif c.Type == "CenterOfMass":
@@ -362,8 +363,12 @@ def Create(doc, constraint, solver, rigid1, rigid2):
             #plane2 = getObjectFaceFromName(ob2, c.SubElement2)
             # dep1.refPoint = plane1.Faces[0].CenterOfMass
             # dep2.refPoint = plane2.Faces[0].CenterOfMass
-            normal1 = plane1.Surface.Axis
-            normal2 = plane2.Surface.Axis
+
+            #normal1 = plane1.Surface.Axis
+            #normal2 = plane2.Surface.Axis
+            normal1 = a2plib.getPlaneNormal(plane1.Surface)
+            normal2 = a2plib.getPlaneNormal(plane2.Surface)
+
             if dep2.direction == "opposed":
                 normal2.multiply(-1.0)
             dep1.refAxisEnd = dep1.refPoint.add(normal1)

a2plib.py

@@ -32,6 +32,8 @@
 import sys
 import copy
 import platform
+import numpy
+
 from a2p_viewProviderProxies import *
 
 PYVERSION =  sys.version_info[0]
@@ -271,6 +273,19 @@ def appVersionStr():
     subVersion = int(float(FreeCAD.Version()[1]))
     return "%03d.%03d" %(version,subVersion)
 #------------------------------------------------------------------------------
+def numpyVecToFC(nv):
+    assert len(nv) == 3
+    return Base.Vector(nv[0],nv[1],nv[2])
+#------------------------------------------------------------------------------
+def fit_plane_to_surface1( surface, n_u=3, n_v=3 ):
+    uv = sum( [ [ (u,v) for u in numpy.linspace(0,1,n_u)] for v in numpy.linspace(0,1,n_v) ], [] )
+    P = [ surface.value(u,v) for u,v in uv ] #positions at u,v points
+    N = [ numpy.cross( *surface.tangent(u,v) ) for u,v in uv ] 
+    plane_norm = sum(N) / len(N) #plane's normal, averaging done to reduce error
+    plane_pos = P[0]
+    error = sum([ abs( numpy.dot(p - plane_pos, plane_norm) ) for p in P ])
+    return numpyVecToFC(plane_norm), numpyVecToFC(plane_pos), error
+#------------------------------------------------------------------------------
 def isLine(param):
     if hasattr(Part,"LineSegment"):
         return isinstance(param,(Part.Line,Part.LineSegment))
@@ -604,6 +619,10 @@ def planeSelected( selection ):
             face = getObjectFaceFromName( selection.Object, subElement)
             if str(face.Surface) == '<Plane object>':
                 return True
+            elif str(face.Surface) == '<BSplineSurface object>':
+                normal,pos,error = fit_plane_to_surface1(face.Surface)
+                if abs(error) < 1e-9:
+                    return True
     return False
 #------------------------------------------------------------------------------
 def vertexSelected( selection ):
@@ -668,6 +687,8 @@ def getPos(obj, subElementName):
             pos = surface.Center
         elif str(surface).startswith('<SurfaceOfRevolution'):
             pos = getObjectFaceFromName(obj, subElementName).Edges[0].Curve.Center
+        elif str(surface).startswith('<BSplineSurface'):
+            axis,pos,error = fit_plane_to_surface1(surface)
     elif subElementName.startswith('Edge'):
         edge = getObjectEdgeFromName(obj, subElementName)
         if isLine(edge.Curve):
@@ -681,6 +702,14 @@ def getPos(obj, subElementName):
         return  getObjectVertexFromName(obj, subElementName).Point
     return pos # maybe none !!
 #------------------------------------------------------------------------------
+def getPlaneNormal(surface):
+    axis = None
+    if hasattr(surface,'Axis'):
+        axis = surface.Axis
+    elif str(surface).startswith('<BSplineSurface'):
+        axis,pos,error = fit_plane_to_surface1(surface)
+    return axis # may be none!
+#------------------------------------------------------------------------------
 def getAxis(obj, subElementName):
     axis = None
     if subElementName.startswith('Face'):
@@ -690,6 +719,9 @@ def getAxis(obj, subElementName):
             axis = surface.Axis
         elif str(surface).startswith('<SurfaceOfRevolution'):
             axis = face.Edges[0].Curve.Axis
+        elif str(surface).startswith('<BSplineSurface'):
+            axis,pos,error = fit_plane_to_surface1(surface)
+
     elif subElementName.startswith('Edge'):
         edge = getObjectEdgeFromName(obj, subElementName)
         if isLine(edge.Curve):