implemented half lap joint

CHANGELOG.md

@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+* Added new joint type: Half-lap joint.
+
 ### Changed
 
 * Beam transformed geometry with features is available using property `geometry`.

src/compas_timber/connections/__init__.py

@@ -20,6 +20,7 @@
     TButtJoint
     LButtJoint
     LMiterJoint
+    XHalfLapJoint
     JointTopology
     ConnectionSolver
 
@@ -47,6 +48,7 @@
 from .t_butt import TButtJoint
 from .l_butt import LButtJoint
 from .l_miter import LMiterJoint
+from .x_halflap import XHalfLapJoint
 from .solver import JointTopology
 from .solver import ConnectionSolver
 from .solver import find_neighboring_beams
@@ -59,6 +61,7 @@
     "TButtJoint",
     "LButtJoint",
     "LMiterJoint",
+    "XHalfLapJoint",
     "JointTopology",
     "ConnectionSolver",
     "find_neighboring_beams",

src/compas_timber/connections/x_halflap.py

@@ -0,0 +1,178 @@
+from compas.geometry import Brep
+from compas.geometry import Frame
+from compas.geometry import Line
+from compas.geometry import Plane
+from compas.geometry import Point
+from compas.geometry import Polyhedron
+from compas.geometry import Vector
+from compas.geometry import angle_vectors
+from compas.geometry import intersection_line_plane
+from compas.geometry import intersection_plane_plane
+from compas.geometry import length_vector
+from compas.geometry import midpoint_point_point
+
+from compas_timber.parts import BeamBooleanSubtraction
+from compas_timber.utils import intersection_line_line_3D
+
+from .joint import Joint
+from .solver import JointTopology
+
+
+class XHalfLapJoint(Joint):
+    SUPPORTED_TOPOLOGY = JointTopology.TOPO_X
+
+    def __init__(self, beam_a=None, beam_b=None, cut_plane_choice=None, frame=None, key=None):
+        super(XHalfLapJoint, self).__init__(frame, key)
+        self.beam_a = beam_a
+        self.beam_b = beam_b
+        self.beam_a_key = beam_a.key if beam_a else None
+        self.beam_b_key = beam_b.key if beam_b else None
+        self.cut_plane_choice = cut_plane_choice  # Decide if Direction of beam_a or beam_b
+        self.features = []
+
+    @property
+    def data(self):
+        data_dict = {
+            "beam_a": self.beam_a_key,
+            "beam_b": self.beam_b_key,
+        }
+        data_dict.update(Joint.data.fget(self))
+        return data_dict
+
+    @classmethod
+    def from_data(cls, value):
+        instance = cls(frame=Frame.from_data(value["frame"]), key=value["key"], cutoff=value["cut_plane_choice"])
+        instance.beam_a_key = value["beam_a"]
+        instance.beam_b_key = value["beam_b"]
+        instance.cut_plane_choice = value["cut_plane_choice"]
+        return instance
+
+    @property
+    def joint_type(self):
+        return "X-HalfLap"
+
+    @property
+    def beams(self):
+        return [self.beam_a, self.beam_b]
+
+    def _cutplane(self):
+        # Find the Point for the Cut Plane
+        centerline_a = self.beam_a.centerline
+        centerline_b = self.beam_b.centerline
+        max_distance = float("inf")
+        int_a, int_b = intersection_line_line_3D(centerline_a, centerline_b, max_distance)
+        int_a, _ = int_a
+        int_b, _ = int_b
+        point_cut = Point(*midpoint_point_point(int_a, int_b))
+
+        # Vector Cross Product
+        beam_a_start = self.beam_a.centerline_start
+        beam_b_start = self.beam_b.centerline_start
+        beam_a_end = self.beam_a.centerline_end
+        beam_b_end = self.beam_b.centerline_end
+        centerline_vec_a = Vector.from_start_end(beam_a_start, beam_a_end)
+        centerline_vec_b = Vector.from_start_end(beam_b_start, beam_b_end)
+        plane_cut = Plane.from_point_and_two_vectors(point_cut, centerline_vec_a, centerline_vec_b)
+
+        # Flip Cut Plane if its Normal Z-Coordinate is positive
+        if plane_cut[1][2] > 0:
+            plane_cut[1] = plane_cut[1] * -1
+
+        # Cutplane Normal Vector pointing from a and b to Cutplane Origin
+        cutplane_vector_a = Vector.from_start_end(int_a, point_cut)
+        cutplane_vector_b = Vector.from_start_end(int_b, point_cut)
+
+        # If Centerlines crossing, take the Cutplane Normal
+        if length_vector(cutplane_vector_a) < 1e-6:
+            cutplane_vector_a = plane_cut.normal
+        if length_vector(cutplane_vector_b) < 1e-6:
+            cutplane_vector_b = plane_cut.normal * -1
+
+        return plane_cut, cutplane_vector_a, cutplane_vector_b
+
+    @staticmethod
+    def _sort_beam_planes(beam, cutplane_vector):
+        # Sorts the Beam Face Planes according to the Cut Plane
+
+        frames = beam.faces[:4]
+        planes = []
+        planes_angles = []
+        for i in frames:
+            planes.append(Plane.from_frame(i))
+            planes_angles.append(angle_vectors(cutplane_vector, i.normal))
+        planes_angles, planes = zip(*sorted(zip(planes_angles, planes)))
+        return planes
+
+    @staticmethod
+    def _create_polyhedron(plane_a, plane_b, lines):  # Hexahedron from 2 Planes and 4 Lines
+        # Step 1: Get 8 Intersection Points from 2 Planes and 4 Lines
+        int_points = []
+        for i in lines:
+            point_top = intersection_line_plane(i, plane_a)
+            point_bottom = intersection_line_plane(i, plane_b)
+            point_top = Point(*point_top)
+            point_bottom = Point(*point_bottom)
+            int_points.append(point_top)
+            int_points.append(point_bottom)
+
+        # Step 2: Check if int_points Order results in an inward facing Polyhedron
+        test_face_vector1 = Vector.from_start_end(int_points[0], int_points[2])
+        test_face_vector2 = Vector.from_start_end(int_points[0], int_points[6])
+        test_face_normal = Vector.cross(test_face_vector1, test_face_vector2)
+        check_vector = Vector.from_start_end(int_points[0], int_points[1])
+        # Flip int_points Order if needed
+        if angle_vectors(test_face_normal, check_vector) < 1:
+            a, b, c, d, e, f, g, h = int_points
+            int_points = b, a, d, c, f, e, h, g
+
+        # Step 3: Create a Hexahedron with 6 Faces from the 8 Points
+        return Polyhedron(
+            int_points,
+            [
+                [1, 7, 5, 3],  # top
+                [0, 2, 4, 6],  # bottom
+                [1, 3, 2, 0],  # left
+                [3, 5, 4, 2],  # back
+                [5, 7, 6, 4],  # right
+                [7, 1, 0, 6],  # front
+            ],
+        )
+
+    def _create_negative_volumes(self):
+        # Get Cut Plane
+        plane_cut, plane_cut_vector_a, plane_cut_vector_b = self._cutplane()
+
+        # Get Beam Faces (Planes) in right order
+        planes_a = self._sort_beam_planes(self.beam_a, plane_cut_vector_a)
+        plane_a0, plane_a1, plane_a2, plane_a3 = planes_a
+
+        planes_b = self._sort_beam_planes(self.beam_b, plane_cut_vector_b)
+        plane_b0, plane_b1, plane_b2, plane_b3 = planes_b
+
+        # Lines as Frame Intersections
+        lines = []
+        x = intersection_plane_plane(plane_a1, plane_b1)
+        lines.append(Line(x[0], x[1]))
+        x = intersection_plane_plane(plane_a1, plane_b2)
+        lines.append(Line(x[0], x[1]))
+        x = intersection_plane_plane(plane_a2, plane_b2)
+        lines.append(Line(x[0], x[1]))
+        x = intersection_plane_plane(plane_a2, plane_b1)
+        lines.append(Line(x[0], x[1]))
+
+        # Create Polyhedrons
+        negative_polyhedron_beam_a = self._create_polyhedron(plane_a0, plane_cut, lines)
+        negative_polyhedron_beam_b = self._create_polyhedron(plane_b0, plane_cut, lines)
+
+        # Create BREP
+        return Brep.from_mesh(negative_polyhedron_beam_a), Brep.from_mesh(negative_polyhedron_beam_b)
+
+    def restore_beams_from_keys(self, assemly):
+        """After de-serialization, resotres references to the main and cross beams saved in the assembly."""
+        self.beam_a = assemly.find_by_key(self.beam_a_key)
+        self.beam_b = assemly.find_by_key(self.beam_b_key)
+
+    def add_features(self):
+        negative_brep_beam_a, negative_brep_beam_b = self._create_negative_volumes()
+        self.beam_a.add_feature(BeamBooleanSubtraction(negative_brep_beam_a))
+        self.beam_b.add_feature(BeamBooleanSubtraction(negative_brep_beam_b))

src/compas_timber/ghpython/components/CT_JointDef_Rule/code.py

@@ -3,12 +3,13 @@
 from compas_timber.connections import LButtJoint
 from compas_timber.connections import LMiterJoint
 from compas_timber.connections import TButtJoint
+from compas_timber.connections import XHalfLapJoint
 from compas_timber.ghpython import CategoryRule
 
 
 class JointCategoryRule(component):
     # TODO: auto fill with subclasses of Joint
-    MAP = {"T-Butt": TButtJoint, "L-Miter": LMiterJoint, "L-Butt": LButtJoint}
+    MAP = {"T-Butt": TButtJoint, "L-Miter": LMiterJoint, "L-Butt": LButtJoint, "X-HalfLap": XHalfLapJoint}
 
     def RunScript(self, JointType, CatA, CatB):
         if JointType and CatA and CatB:

src/compas_timber/ghpython/components/CT_JointDef_XHalfLap/code.py

@@ -0,0 +1,39 @@
+from ghpythonlib.componentbase import executingcomponent as component
+from Grasshopper.Kernel.GH_RuntimeMessageLevel import Error
+from Grasshopper.Kernel.GH_RuntimeMessageLevel import Warning
+
+from compas_timber.connections import ConnectionSolver
+from compas_timber.connections import XHalfLapJoint
+from compas_timber.connections import JointTopology
+from compas_timber.ghpython import JointDefinition
+
+
+class XHalfLapDefinition(component):
+    def RunScript(self, MainBeam, CrossBeam):
+        if not MainBeam:
+            self.AddRuntimeMessage(Warning, "Input parameter MainBeams failed to collect data.")
+        if not CrossBeam:
+            self.AddRuntimeMessage(Warning, "Input parameter CrossBeams failed to collect data.")
+        if not (MainBeam and CrossBeam):
+            return
+        if not isinstance(MainBeam, list):
+            MainBeam = [MainBeam]
+        if not isinstance(CrossBeam, list):
+            CrossBeam = [CrossBeam]
+        if len(MainBeam) != len(CrossBeam):
+            self.AddRuntimeMessage(Error, "Number of items in MainBeams and CrossBeams must match!")
+            return
+        Joint = []
+        for main, cross in zip(MainBeam, CrossBeam):
+            max_distance_from_beams = max([main.width, main.height, cross.width, cross.height])
+            topology, _, _ = ConnectionSolver().find_topology(main, cross, max_distance=max_distance_from_beams)
+            if topology != XHalfLapJoint.SUPPORTED_TOPOLOGY:
+                self.AddRuntimeMessage(
+                    Warning,
+                    "Beams meet with topology: {} which does not agree with joint of type: {}".format(
+                        JointTopology.get_name(topology), XHalfLapJoint.__name__
+                    ),
+                )
+                continue
+            Joint.append(JointDefinition(XHalfLapJoint, [main, cross]))
+        return Joint

src/compas_timber/ghpython/components/CT_JointDef_XHalfLap/metadata.json

@@ -0,0 +1,32 @@
+{
+    "name": "JointDef: XHalfLap",
+    "nickname": "JointDef: XHalfLap",
+    "category": "COMPAS Timber",
+    "subcategory": "Joints",
+    "description": "Defines an X-HalfLap Joint for the given two Beams.",
+    "exposure": 4,
+    "ghpython": {
+        "isAdvancedMode": true,
+        "iconDisplay": 0,
+        "inputParameters": [
+            {
+                "name": "BeamA",
+                "description": "First Beam.",
+                "typeHintID": "none",
+                "scriptParamAccess": 1
+            },
+            {
+                "name": "BeamB",
+                "description": "Second Beam.",
+                "typeHintID": "none",
+                "scriptParamAccess": 1
+            }
+        ],
+        "outputParameters": [
+            {
+                "name": "Joint",
+                "description": "XHalfLap JointDefinition."
+            }
+        ]
+    }
+}