GITBOOK materialization bottom mesh

Author: petrasvestartas

gitbook/.gitbook/assets/materialization.zip

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+#! python3
+# venv: brg-csd
+# r: compas_rv
+
+import pathlib
+import compas
+from compas.scene import Scene
+
+# =============================================================================
+# Load data
+# =============================================================================
+IFILE = pathlib.Path(__file__).parent / "rhinovault_session.json"
+rv_session = compas.json_load(IFILE)
+rv_scene: Scene = rv_session["scene"]
+pattern = rv_scene.find_by_name("Pattern").mesh
+
+# =============================================================================
+# Visualisation
+# =============================================================================
+scene = Scene()
+scene.clear_context()
+scene.add(rv_scene.find_by_name("Pattern").mesh)
+scene.draw()

gitbook/.gitbook/assets/materialization_000_rhinovault_session.py

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+#! python3
+# venv: brg-csd
+# r: compas_rv
+
+import pathlib
+
+import compas
+from compas.datastructures import Mesh
+from compas.scene import Scene
+from compas_tna.diagrams import FormDiagram
+from compas import json_dump
+from compas.itertools import pairwise
+
+
+def break_boundary(mesh: Mesh, breakpoints: list[int]) -> tuple[list[list[int]], list[int]]:
+
+    # Get the list of vertices on the boundary (first boundary from the mesh)
+    # If the first and last vertices in the boundary are the same, remove the last vertex (close loop)
+    boundary: list[int] = mesh.vertices_on_boundaries()[0]
+    
+    if boundary[0] == boundary[-1]:
+        del boundary[-1]
+
+    # Sort the breakpoints based on their index in the boundary
+    # Find the starting point in the boundary for the first breakpoint
+    # Rearrange the boundary to start from the first breakpoint
+    breakpoints = sorted(breakpoints, key=lambda s: boundary.index(s))
+    start = boundary.index(breakpoints[0])
+    boundary = boundary[start:] + boundary[:start]
+
+    # Iterate over pairs of breakpoints and create sub-boundaries from the main boundary
+    borders = []
+    
+    for a, b in pairwise(breakpoints):
+        start = boundary.index(a)  # Find index of the first breakpoint in the boundary
+        end = boundary.index(b)    # Find index of the second breakpoint in the boundary
+        borders.append(boundary[start : end + 1])  # Add the sub-boundary from start to end
+
+    # Add the last segment from the last breakpoint to the first one to close the loop
+    borders.append(boundary[end:] + boundary[:1])
+
+    # Return the sub-boundaries and the breakpoints
+    return borders, breakpoints
+
+
+# =============================================================================
+# Load data
+# =============================================================================
+
+IFILE = pathlib.Path(__file__).parent / "rhinovault_session.json"
+
+rv_session = compas.json_load(IFILE)
+rv_scene: Scene = rv_session["scene"]
+
+thrustobject = rv_scene.find_by_name("ThrustDiagram")
+thrustdiagram: FormDiagram = thrustobject.mesh
+
+# =============================================================================
+# Mesh
+#
+# - make a copy of the thrustdiagram
+# - remove the "TNA" faces cooresponding to boundary openings
+# - compute the average edge length for remeshing
+# =============================================================================
+
+mesh: Mesh = thrustdiagram.copy(cls=Mesh)
+
+for face in list(mesh.faces_where(_is_loaded=False)):
+    mesh.delete_face(face)
+
+# =============================================================================
+# Mesh: Borders
+# =============================================================================
+
+supports = list(mesh.vertices_where(is_support=True))
+borders, supports = break_boundary(mesh, supports)
+print(borders)
+print(supports)
+
+mesh.attributes["supports"] = supports
+mesh.attributes["borders"] = borders
+
+# =============================================================================
+# Serialize
+# =============================================================================
+
+json_dump(mesh, pathlib.Path(__file__).parent / "001_mesh.json")
+
+# =============================================================================
+# Visualisation
+# =============================================================================
+
+scene = Scene()
+# scene.clear_context()
+scene.add(mesh)
+scene.draw()

gitbook/.gitbook/assets/materialization_001_mesh_from_thrust_diagram.py

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+#! python3
+# venv: brg-csd
+# r: compas_rv
+
+import pathlib
+
+import compas
+from compas.datastructures import Mesh
+from compas.scene import Scene
+from compas import json_dump
+from compas.datastructures.mesh.remesh import trimesh_remesh
+from compas.geometry import Line
+from compas.geometry import normal_triangle
+from compas.geometry import KDTree
+from compas_model.geometry import intersection_ray_triangle
+
+# =============================================================================
+# Load data
+# =============================================================================
+
+IFILE = pathlib.Path(__file__).parent / "001_mesh.json"
+mesh = compas.json_load(IFILE)
+
+# =============================================================================
+# Trimesh
+#
+# - convert a copy of the mesh to a trimesh using "quads to triangles"
+# - note that this doesn't work for other patterns
+# =============================================================================
+
+trimesh: Mesh = mesh.copy()
+trimesh.quads_to_triangles()
+
+# =============================================================================
+# Trimesh: Remeshing
+#
+# - remesh using CGAL
+# - use a percentage of the average edge length of the original mesh as target length
+# =============================================================================
+
+
+length = sum(mesh.edge_length(edge) for edge in mesh.edges()) / mesh.number_of_edges()
+
+def project(mesh: Mesh, k, args):
+    for vertex in mesh.vertices():
+        if mesh.is_vertex_on_boundary(vertex):
+            continue
+        point = mesh.vertex_point(vertex)
+        _, nbr, _ = tree.nearest_neighbor(point)
+        triangles = vertex_triangles[nbr]
+        for triangle in triangles:
+            normal = normal_triangle(triangle)
+            ray = Line.from_point_direction_length(point, normal, 10)
+            result = intersection_ray_triangle(ray, triangle)
+            if result:
+                mesh.vertex_attributes(vertex, "xyz", result)
+                break
+
+vertex_index = {vertex: index for index, vertex in enumerate(trimesh.vertices())}
+vertex_triangles = {vertex_index[vertex]: [trimesh.face_points(face) for face in trimesh.vertex_faces(vertex)] for vertex in trimesh.vertices()}
+vertices = trimesh.vertices_attributes("xyz")
+tree = KDTree(vertices)
+
+fixed = list(trimesh.vertices_on_boundary())
+free = set(list(trimesh.vertices())) - set(fixed)
+
+trimesh_remesh(trimesh, length, kmax=300, tol=0.1, allow_boundary_split=False, callback=project)
+
+
+# =============================================================================
+# Serialize
+# =============================================================================
+
+json_dump(trimesh, pathlib.Path(__file__).parent / "002_mesh.json")
+
+# =============================================================================
+# Visualisation
+# =============================================================================
+
+scene = Scene()
+scene.clear_context()
+scene.add(trimesh)
+scene.draw()

gitbook/.gitbook/assets/materialization_002_remesh.py

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+#! python3
+# venv: brg-csd
+# r: compas_rv
+
+import pathlib
+
+import compas
+from compas.datastructures import Mesh
+from compas.scene import Scene
+from compas import json_dump
+
+# =============================================================================
+# Load data
+# =============================================================================
+
+IFILE = pathlib.Path(__file__).parent / "002_mesh.json"
+trimesh = compas.json_load(IFILE)
+
+# =============================================================================
+# Dual
+#
+# - construct a dual
+# - update default attributes
+# - flip the cycles because a dual has opposite cycles compared to the original
+# =============================================================================
+
+dual: Mesh = trimesh.dual(include_boundary=True)
+
+dual.update_default_edge_attributes(is_support=False)
+dual.update_default_face_attributes(number=None, batch=None)
+dual.update_default_vertex_attributes(thickness=0, is_corner=False, is_support=False)
+
+dual.flip_cycles()
+
+
+# =============================================================================
+# Serialize
+# =============================================================================
+
+json_dump(dual, pathlib.Path(__file__).parent / "003_mesh.json")
+
+# =============================================================================
+# Visualisation
+# =============================================================================
+
+scene = Scene()
+scene.clear_context()
+scene.add(dual, show_vertices=True)
+scene.draw()

gitbook/.gitbook/assets/materialization_003_dual.py

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+#! python3
+# venv: brg-csd
+# r: compas_rv
+
+import pathlib
+
+import compas
+from compas.scene import Scene
+from compas import json_dump
+from compas.geometry import KDTree
+from compas.geometry import Sphere
+
+# =============================================================================
+# Load data
+# =============================================================================
+
+IFILE = pathlib.Path(__file__).parent / "003_mesh.json"
+dual = compas.json_load(IFILE)
+
+IFILE = pathlib.Path(__file__).parent / "001_mesh.json"
+mesh = compas.json_load(IFILE)
+
+# =============================================================================
+# Dual: Reconnect corners
+#
+# - construct a KD tree for nearest neighbour search
+# - find the nearest neighbours in the dual to the supports of the original
+# - snap the dual vertices to the location of the supports
+# - mark the corresponding vertices as "corners"
+# =============================================================================
+
+vertices = dual.vertices_attributes("xyz")
+vertex_index = {vertex: index for index, vertex in enumerate(dual.vertices())}
+index_vertex = {index: vertex for index, vertex in enumerate(dual.vertices())}
+tree = KDTree(vertices)
+
+spheres = []
+for vertex in mesh.vertices_where(is_support=True):
+    point = mesh.vertex_point(vertex)
+    closest, nnbr, distance = tree.nearest_neighbor(point)
+    dual_vertex = index_vertex[nnbr]
+    if distance > 5:
+        dual.vertex_attributes(dual_vertex, names="xyz", values=point)
+    dual.vertex_attribute(dual_vertex, name="is_corner", value=True)
+    spheres.append(Sphere(10, point=point))
+
+
+# =============================================================================
+# Serialize
+# =============================================================================
+
+json_dump(dual, pathlib.Path(__file__).parent / "004_mesh.json")
+
+# =============================================================================
+# Visualisation
+# =============================================================================
+
+scene = Scene()
+scene.clear_context()
+scene.add(dual, show_vertices=True)
+for sphere in spheres:
+    scene.add(sphere)
+scene.draw()

gitbook/.gitbook/assets/materialization_004_dual_corners.py

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+
+#! python3
+# venv: brg-csd
+# r: compas_rv
+
+import pathlib
+
+import compas
+from compas.scene import Scene
+from compas import json_dump
+
+# =============================================================================
+# Load data
+# =============================================================================
+
+IFILE = pathlib.Path(__file__).parent / "004_mesh.json"
+dual = compas.json_load(IFILE)
+
+# =============================================================================
+# Dual: Collapse 2-valent boundary edges
+# =============================================================================
+
+tofix = []
+
+for vertex in dual.vertices_on_boundary():
+    if dual.vertex_degree(vertex) > 2:
+        continue
+    tofix.append(vertex)
+
+for vertex in tofix:
+    nbrs = dual.vertex_neighbors(vertex)
+    v0 = dual.edge_vector((vertex, nbrs[0]))
+    v1 = dual.edge_vector((vertex, nbrs[1]))
+    angle = v0.angle(v1, degrees=True)
+
+    if abs(angle - 180) > 30:
+        continue
+
+    if dual.has_edge((vertex, nbrs[0])):
+        is_corner = dual.vertex_attribute(nbrs[0], name="is_corner")
+        dual.collapse_edge((vertex, nbrs[0]), t=1, allow_boundary=True)
+    else:
+        is_corner = dual.vertex_attribute(nbrs[1], name="is_corner")
+        dual.collapse_edge((vertex, nbrs[1]), t=1, allow_boundary=True)
+
+    if is_corner:
+        dual.vertex_attribute(vertex, name="is_corner", value=True)
+
+# =============================================================================
+# Serialize
+# =============================================================================
+
+json_dump(dual, pathlib.Path(__file__).parent / "005_mesh.json")
+
+# =============================================================================
+# Visualisation
+# =============================================================================
+
+scene = Scene()
+scene.clear_context()
+scene.add(dual, show_vertices=True)
+scene.draw()