3D ray-tracing

[jorgensd]

Implements raytracing for 3D cells.

MWE:

import dolfinx_contact
from mpi4py import MPI
import dolfinx
import numpy as np

mesh = dolfinx.mesh.create_unit_cube(MPI.COMM_WORLD, 15, 15, 15, dolfinx.mesh.CellType.tetrahedron)
facets = dolfinx.mesh.locate_entities_boundary(mesh, mesh.topology.dim - 1, lambda x: np.isclose(x[2], 0))
integral_pairs = dolfinx_contact.cpp.compute_active_entities(mesh, facets, dolfinx.fem.IntegralType.exterior_facet)

status, cell_idx, points = dolfinx_contact.cpp.compute_3D_ray(
    mesh, [0.5, 0.3, -1], [[1, 0, 0], [0, 1, 0]], integral_pairs, 10, 1e-6)
print(
    f"Converged: {status} Entity: {integral_pairs[cell_idx]} Coordinate {points[0]} Reference Coordinate: {points[1]}")

If no cell is found that the ray goes through, a negative status is returned