Fixed some ThreeDCamera bugs

camera/camera.py

@@ -348,7 +348,7 @@ class Camera(object):
     def set_cairo_context_path(self, ctx, vmobject):
         ctx.new_path()
         for vmob in it.chain([vmobject], vmobject.get_subpath_mobjects()):
-            points = vmob.points
+            points = self.transform_points_pre_display(vmob.points)
             ctx.new_sub_path()
             ctx.move_to(*points[0][:2])
             for triplet in zip(points[1::3], points[2::3], points[3::3]):
@@ -543,7 +543,13 @@ class Camera(object):
         points[violator_indices] = rescaled
         return points
 
+    def transform_points_pre_display(self, points):
+        # Subclasses (like ThreeDCamera) may want to
+        # adjust points before they're shown
+        return points
+
     def points_to_pixel_coords(self, points):
+        points = self.transform_points_pre_display(points)
         shifted_points = points - self.get_frame_center()
 
         result = np.zeros((len(points), 2))

camera/three_d_camera.py

@@ -80,7 +80,7 @@ class ThreeDCamera(MovingCamera):
         else:
             target[:, :3] = 0
             alpha = -self.shading_factor * brightness
-            return interpolate(rgb, target, alpha)
+            return interpolate(rgbas, target, alpha)
 
     def get_unit_normal_vect(self, vmobject):
         anchors = vmobject.get_anchors()
@@ -172,9 +172,9 @@ class ThreeDCamera(MovingCamera):
             rotation_about_z(-self.get_theta() - np.pi / 2),
         )
 
-    def points_to_pixel_coords(self, points):
+    def transform_points_pre_display(self, points):
         matrix = self.get_view_transformation_matrix()
-        new_points = np.dot(points, matrix.T)
-        self.frame_center = self.moving_center.points[0]
+        return np.dot(points, matrix.T)
 
-        return MovingCamera.points_to_pixel_coords(self, new_points)
+    def get_frame_center(self):
+        return self.moving_center.points[0]