feat: Polyhedral connectivity

[mkundu1]

import pyvista as pv
import ansys.fluent.core as pyfluent
from ansys.fluent.core.services.field_data import CellElementType

def convert_fluent_element_type_to_pv_cell_type(element_type):
    if element_type == CellElementType.POLYHEDRON:
        return pv.CellType.POLYHEDRON
    # Add other element types
    raise ValueError(f"Unknown element type {element_type}")

solver = pyfluent.launch_fluent(processor_count=4)
solver.settings.file.read_case(file_name="d:/work/Static_Mixer_main.cas.h5")
mesh = solver.fields.field_data.get_mesh(zone_id=97)
points = [(node.x, node.y, node.z) for node in mesh.nodes]
cells = []
for element in mesh.elements:
    connectivity = []
    connectivity.append(len(element.facets))
    for facet in element.facets:
        connectivity.append(len(facet.node_indices))
        connectivity.extend(facet.node_indices)
    cells.append(len(connectivity))
    cells.extend(connectivity)
cell_types = [convert_fluent_element_type_to_pv_cell_type(element.element_type) for element in mesh.elements]
grid = pv.UnstructuredGrid(cells, cell_types, points)
pv.plot(grid, show_edges=True)