fix triangle normal initialization

git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@78 bbaffbd6-741e-11dd-a85d-61de82d9cad9

pycam/Geometry/Triangle.py

@@ -14,7 +14,7 @@ except:
 class Triangle:
     id = 0
     # points are expected to be in ClockWise order
-    def __init__(self, p1=None, p2=None, p3=None, e1=None, e2=None, e3=None):
+    def __init__(self, p1=None, p2=None, p3=None, e1=None, e2=None, e3=None, n=None):
         self.id = Triangle.id
         Triangle.id += 1
         self.p1 = p1
@@ -32,6 +32,7 @@ class Triangle:
             self.e3 = Line(p3,p1)
         else:
             self.e3 = e3
+        self._normal = n
         self._minx = None
         self._miny = None
         self._minz = None
@@ -42,7 +43,6 @@ class Triangle:
         self._middle = None
         self._radius = None
         self._radiussq = None
-        self._normal = None
         self._plane = None
 
     def __repr__(self):

pycam/Importers/STLImporter.py

@@ -185,9 +185,9 @@ def ImportModel(filename, use_kdtree=True):
                 # make sure the points are in ClockWise order
                 dotcross = n.dot(p3.sub(p1).cross(p2.sub(p1)))
                 if dotcross > 0:
-                    t = Triangle(p1, p2, p3, UniqueEdge(p1,p2), UniqueEdge(p2,p3), UniqueEdge(p3,p1))
+                    t = Triangle(p1, p2, p3, UniqueEdge(p1,p2), UniqueEdge(p2,p3), UniqueEdge(p3,p1), n)
                 elif dotcross < 0:
-                    t = Triangle(p1, p3, p2, UniqueEdge(p1,p3), UniqueEdge(p3,p2), UniqueEdge(p2,p1))
+                    t = Triangle(p1, p3, p2, UniqueEdge(p1,p3), UniqueEdge(p3,p2), UniqueEdge(p2,p1), n)
                 else:
                     # the three points are in a line - or two points are identical
                     # usually this is caused by points, that are too close together
@@ -195,10 +195,7 @@ def ImportModel(filename, use_kdtree=True):
                     print "ERROR: skipping invalid triangle: %s / %s / %s" % (p1, p2, p3)
                     n=p1=p2=p3=None
                     continue
-                t._normal = n
                 n=p1=p2=p3=None
-                if t.normal().z < 0:
-                    continue
                 model.append(t)
                 continue
             m = endsolid.match(line)