def triangulate(vertices):
t = Triangulator()
for i, v in enumerate(vertices):
t.add_vertex(v)
t.add_polygon_vertex(i)
t.triangulate()
# Make sure that the result is consistent by starting each triangle with
# the lowest index value. That makes it easier to use predetermined values
# in the test cases.
result = set()
for n in range(t.get_num_triangles()):
# Switch to lowest matching index value in case of duplicates.
v0 = vertices.index(vertices[t.get_triangle_v0(n)])
v1 = vertices.index(vertices[t.get_triangle_v1(n)])
v2 = vertices.index(vertices[t.get_triangle_v2(n)])
if v1 < v0:
v0, v1, v2 = v1, v2, v0
if v1 < v0:
v0, v1, v2 = v1, v2, v0
result.add((v0, v1, v2))
return result
def create_plane_mesh(vertices, vertices_floor, textures, texture_floor, texture_ceiling,
delta_height, ignore_ceiling=False):
# create mesh for 3D floorplan visualization
triangles = []
triangle_uvs = []
# the number of vertical walls
num_walls = len(vertices)
# 1. vertical wall (always rectangle)
num_vertices = 0
for i in range(len(vertices)):
# hardcode triangles for each vertical wall
triangle = np.array([[0, 2, 1], [2, 0, 3]])
triangles.append(triangle + num_vertices)
num_vertices += 4
triangle_uv = np.array(
[
[i / (num_walls + 2), 0],
[i / (num_walls + 2), 1],
[(i+1) / (num_walls + 2), 1],
[(i+1) / (num_walls + 2), 0]
],
dtype=np.float32
)
triangle_uvs.append(triangle_uv)
# 2. floor and ceiling
# Since the floor and ceiling may not be a rectangle, triangulate the polygon first.
tri = Triangulator()
for i in range(len(vertices_floor)):
tri.add_vertex(vertices_floor[i, 0], vertices_floor[i, 1])
for i in range(len(vertices_floor)):
tri.add_polygon_vertex(i)
tri.triangulate()
# polygon triangulation
triangle = []
for i in range(tri.getNumTriangles()):
triangle.append([tri.get_triangle_v0(i), tri.get_triangle_v1(i), tri.get_triangle_v2(i)])
triangle = np.array(triangle)
# add triangles for floor and ceiling
triangles.append(triangle + num_vertices)
num_vertices += len(np.unique(triangle))
if not ignore_ceiling:
triangles.append(triangle + num_vertices)
# texture for floor and ceiling
vertices_floor_min = np.min(vertices_floor[:, :2], axis=0)
vertices_floor_max = np.max(vertices_floor[:, :2], axis=0)
# normalize to [0, 1]
triangle_uv = (vertices_floor[:, :2] - vertices_floor_min) / (vertices_floor_max - vertices_floor_min)
triangle_uv[:, 0] = (triangle_uv[:, 0] + num_walls) / (num_walls + 2)
triangle_uvs.append(triangle_uv)
# normalize to [0, 1]
triangle_uv = (vertices_floor[:, :2] - vertices_floor_min) / (vertices_floor_max - vertices_floor_min)
triangle_uv[:, 0] = (triangle_uv[:, 0] + num_walls + 1) / (num_walls + 2)
triangle_uvs.append(triangle_uv)
# 3. Merge wall, floor, and ceiling
vertices.append(vertices_floor)
vertices.append(vertices_floor + delta_height)
vertices = np.concatenate(vertices, axis=0)
triangles = np.concatenate(triangles, axis=0)
textures.append(texture_floor)
textures.append(texture_ceiling)
textures = np.concatenate(textures, axis=1)
triangle_uvs = np.concatenate(triangle_uvs, axis=0)
mesh = open3d.geometry.TriangleMesh(
vertices=open3d.utility.Vector3dVector(vertices),
triangles=open3d.utility.Vector3iVector(triangles)
)
mesh.compute_vertex_normals()
mesh.texture = open3d.geometry.Image(textures)
mesh.triangle_uvs = np.array(triangle_uvs[triangles.reshape(-1), :], dtype=np.float64)
return mesh
