Merge pull request #1415 from compas-dev/frame-inversion

Frame inversion

CHANGELOG.md

@@ -10,10 +10,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * Added implementation of `RhinoBrep.fillet()` and `RhinoBrep.filleted()` to `compas_rhino`.
+* Added `Frame.invert` and `Frame.inverted`.
+* Added `Frame.flip` and `Frame.flipped` as alias for invert and inverted.
+* Added `Vector.flip` and `Vector.flipped` as alias for invert and inverted.
 
 ### Changed
 
 * Fixed `native_edge` property of `RhinoBrepEdge`.
+* Expose the parameters `radius` and `nmax` from `compas.topology._face_adjacency` to `compas.topology.face_adjacency` and further propagate them to `unify_cycles` and `Mesh.unify_cycles`.
+* Modify `face_adjacency` to avoid using `compas.topology._face_adjacency` by default when there are more than 100 faces, unless one of the parameters `radius`, `nmax` is passed.
+* Changed `unify_cycles` to use the first face in the list as root if no root is provided.
 
 ### Removed
 
@@ -32,8 +38,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 * Fixed `PluginNotInstalledError` when using `Brep.from_boolean_*` in Rhino.
-* Expose the parameters `radius` and `nmax` from `compas.topology._face_adjacency` to `compas.topology.face_adjacency` and further propagate them to `unify_cycles` and `Mesh.unify_cycles`.
-* Modify `face_adjacency` to avoid using `compas.topology._face_adjacency` by default when there are more than 100 faces, unless one of the parameters `radius`, `nmax` is passed
 * Added support for `Polyline` as input for `compas_rhino.Brep.from_extrusion`.
 
 ### Removed

src/compas/geometry/frame.py

@@ -604,6 +604,21 @@ def to_transformation(self):
     # Methods
     # ==========================================================================
 
+    def invert(self):
+        """Invert the frame while keeping the X axis fixed."""
+        self._yaxis = self.yaxis * -1
+        self._zaxis = None
+
+    flip = invert
+
+    def inverted(self):
+        """Return an inverted copy of the frame."""
+        frame = self.copy()  # type: Frame
+        frame.invert()
+        return frame
+
+    flipped = inverted
+
     def interpolate_frame(self, other, t):
         """Interpolates between two frames at a given parameter t in the range [0, 1]
 

src/compas/geometry/vector.py

@@ -679,6 +679,8 @@ def invert(self):
         """
         self.scale(-1.0)
 
+    flip = invert
+
     def inverted(self):
         """Returns a inverted copy of this vector
 
@@ -697,6 +699,8 @@ def inverted(self):
         """
         return self.scaled(-1.0)
 
+    flipped = inverted
+
     def scale(self, n):
         """Scale this vector by a factor n.
 

src/compas/topology/orientation.py

@@ -2,8 +2,6 @@
 from __future__ import division
 from __future__ import print_function
 
-import random
-
 from compas.geometry import centroid_points
 from compas.itertools import pairwise
 from compas.topology import breadth_first_traverse
@@ -193,6 +191,11 @@ def unify_cycles(vertices, faces, root=None, nmax=None, max_distance=None):
     Exception
         If no all faces are included in the unnification process.
 
+    Notes
+    -----
+    The cycles of the faces will be aligned with the cycle direction of the root face.
+    If no root face is specified, the first face in the list will be used.
+
     """
 
     def unify(node, nbr):
@@ -210,7 +213,8 @@ def unify(node, nbr):
                     return
 
     if root is None:
-        root = random.choice(list(range(len(faces))))
+        # root = random.choice(list(range(len(faces))))
+        root = 0
 
     adj = face_adjacency(vertices, faces, nmax=nmax, max_distance=max_distance)  # this is the only place where the vertex coordinates are used
 

tests/compas/geometry/test_frame.py

@@ -92,3 +92,35 @@ def test_interpolate_frame_start_end():
 
     three_quarter_frame = frame1.interpolate_frame(frame2, 0.75)
     assert TOL.is_allclose([math.degrees(three_quarter_frame.axis_angle_vector.y)], [-67.5], atol=TOL.angular)
+
+
+def test_frame_invert():
+    frame = Frame([0, 0, 0])
+
+    assert TOL.is_close(frame.xaxis.dot([1, 0, 0]), 1.0)
+    assert TOL.is_close(frame.yaxis.dot([0, 1, 0]), 1.0)
+    assert TOL.is_close(frame.zaxis.dot([0, 0, 1]), 1.0)
+
+    frame.invert()
+
+    assert TOL.is_close(frame.xaxis.dot([1, 0, 0]), 1.0)
+    assert TOL.is_close(frame.yaxis.dot([0, -1, 0]), 1.0)
+    assert TOL.is_close(frame.zaxis.dot([0, 0, -1]), 1.0)
+
+
+def test_frame_inverted():
+    frame = Frame([0, 0, 0])
+
+    assert TOL.is_close(frame.xaxis.dot([1, 0, 0]), 1.0)
+    assert TOL.is_close(frame.yaxis.dot([0, 1, 0]), 1.0)
+    assert TOL.is_close(frame.zaxis.dot([0, 0, 1]), 1.0)
+
+    other = frame.inverted()
+
+    assert TOL.is_close(frame.xaxis.dot([1, 0, 0]), 1.0)
+    assert TOL.is_close(frame.yaxis.dot([0, 1, 0]), 1.0)
+    assert TOL.is_close(frame.zaxis.dot([0, 0, 1]), 1.0)
+
+    assert TOL.is_close(other.xaxis.dot([1, 0, 0]), 1.0)
+    assert TOL.is_close(other.yaxis.dot([0, -1, 0]), 1.0)
+    assert TOL.is_close(other.zaxis.dot([0, 0, -1]), 1.0)

tests/compas/topology/test_unify_cycles.py

@@ -14,6 +14,7 @@
 def test_unify_cycles():
     if compas.IPY:
         return
+
     test_data = compas.json_load(os.path.join(HERE, "..", "fixtures", "topology", "vertices_faces.json"))
     vertices = test_data["vertices"]
     faces = test_data["faces"]
@@ -25,12 +26,15 @@ def test_unify_cycles():
     # no parameters
     unify_cycles(vertices, faces)
     assert TOL.is_close(volume, volume_polyhedron((vertices, faces)))
+
     # only max_nbrs
     unify_cycles(vertices, faces, nmax=max_nbrs)
     assert TOL.is_close(volume, volume_polyhedron((vertices, faces)))
+
     # only max_distance
     unify_cycles(vertices, faces, max_distance=max_edge_length)
     assert TOL.is_close(volume, volume_polyhedron((vertices, faces)))
+
     # both parameters
     unify_cycles(vertices, faces, nmax=max_nbrs, max_distance=max_edge_length)
     assert TOL.is_close(volume, volume_polyhedron((vertices, faces)))