PyVista demo of rasterization

pyvista_raster_demo.py

import numpy as np
import pyvista as pv
from matplotlib.colors import ListedColormap


def add_vertex(plotter, point):
    vertex = pv.Sphere(center=point)
    plotter.add_mesh(
        mesh=vertex,
        color='white',
        specular=1.0,
        smooth_shading=True,
        show_scalar_bar=False,
    )


def add_edge(plotter, point_a, point_b, show_vertex=True):
    edge = pv.Line(pointa=point_a, pointb=point_b)
    edge = edge.tube(radius=0.3)
    plotter.add_mesh(
        mesh=edge,
        color='white',
        specular=1.0,
        smooth_shading=True,
        show_scalar_bar=False,
    )
    if show_vertex:
        add_vertex(plotter, point_a)
        add_vertex(plotter, point_b)


def add_triangle(plotter, point_a, point_b, point_c, show_vertex=True):
    add_edge(plotter, point_a, point_b, show_vertex=False)
    add_edge(plotter, point_a, point_c, show_vertex=False)
    add_edge(plotter, point_b, point_c, show_vertex=False)
    vertices = np.array([point_a, point_b, point_c])
    faces = np.hstack([[3, 0, 1, 2]])
    surf = pv.PolyData(vertices, faces)
    plotter.add_mesh(
        mesh=surf,
        color='white',
        specular=1.0,
        smooth_shading=True,
        show_scalar_bar=False,
    )
    if show_vertex:
        add_vertex(plotter, point_a)
        add_vertex(plotter, point_b)
        add_vertex(plotter, point_c)


def new_plotter():
    plotter = pv.Plotter(
        point_smoothing=True,
        polygon_smoothing=True,
    )
    plotter.enable_anti_aliasing()
    plotter.set_background('white')
    plotter.enable_parallel_projection()
    plotter.view_xy()
    plotter.camera_position = [
        (4.152619223710567, 4.788850261289111, 1.0),
        (4.152619223710567, 4.788850261289111, 0.0),
        (0.0, 1.0, 0.0)
    ]
    return plotter


# raw data
plotter = new_plotter()
zpos = -1
vertex = (2.5, 2.5, zpos)

edge = [
    (5, 0, zpos),
    (10, 5, zpos),
]

triangle = [
    (0, 5, zpos),
    (5, 5, zpos),
    (2.5, 10, zpos),
]

add_vertex(plotter, vertex)
add_edge(plotter, edge[0], edge[1])
add_triangle(plotter, triangle[0], triangle[1], triangle[2])
plotter.show()


# rasterized
plotter = new_plotter()
cmap = [
    (0, 0, 0, 0),
    (255, 255, 255, 255),
]
ctable = np.round(cmap).astype(np.uint8)
ctable = ListedColormap(ctable / 255.)
grid = pv.UniformGrid()
grid.dimensions = (11, 11, 1)
grid.origin = (0, 0, 0)
grid.spacing = (1, 1, 1)
ncells = grid.number_of_cells
scalars = np.array([0] * ncells)
# vertex
scalars[22] = 1
# edge
for i in range(5):
    scalars[5 + i*10 + i] = 1
# triangle
for i in range(5):
    scalars[50 + i] = 1
for i in range(5):
    scalars[60 + i] = 1
scalars[71] = 1
scalars[72] = 1
scalars[73] = 1
scalars[81] = 1
scalars[82] = 1
scalars[83] = 1
scalars[92] = 1
grid.cell_arrays["data"] = scalars
plotter.add_mesh(
    mesh=grid,
    scalars="data",
    cmap=ctable,
    show_scalar_bar=False,
)

# grid
edges = grid.extract_all_edges()
plotter.add_mesh(edges, color='black', line_width=4)
plotter.show()