Mesh Dual Remeshing

This example demonstrates how to remesh a triangle mesh using COMPAS CGAL.

Key Features:

• Constrained Remeshing with Fixed Vertices
• Dual Remeshing with Target Edge Length
• Dual vertices are fixed by angle or/and vertex index.

from pathlib import Path

from compas.datastructures import Mesh
from compas.geometry import Line
from compas_viewer import Viewer

from compas_cgal.meshing import trimesh_dual

# =============================================================================
# Input mesh
# =============================================================================

input_file = Path(__file__).parent.parent.parent / "data" / "rhinovault_mesh_0.ply"
mesh = Mesh.from_ply(input_file)
mesh.quads_to_triangles()

fixed_vertices = []
for v in mesh.vertices():
    if mesh.vertex_point(v).z < 0.01:
        fixed_vertices.append(v)

VF = mesh.to_vertices_and_faces()

# =============================================================================
# Remesh
# =============================================================================

V2, F2, V3, F3 = trimesh_dual(
    VF,
    length_factor=1.0,
    number_of_iterations=100,
    angle_radians=0.9,
    fixed_vertices=fixed_vertices,
)

remeshed = Mesh.from_vertices_and_faces(V2, F2)
dual = Mesh.from_vertices_and_faces(V3, F3)

# ==============================================================================
# Visualize
# ==============================================================================

remeshed.translate([0, 0, 3])

viewer = Viewer(width=1600, height=900)

viewer.scene.add(mesh, show_points=False, opacity=0.25)
viewer.scene.add(remeshed, show_points=True)
viewer.scene.add(dual, show_points=True)

for v in dual.vertices():
    viewer.scene.add(
        Line(
            dual.vertex_point(v),
            dual.vertex_point(v) + dual.vertex_normal(v) * 0.25,
        ),
        color=(255, 0, 0),
    )

viewer.show()