def _create_hole(smoothness):
# calculate vertices of square
square_vertices = np.array([
[0.5, 0.5, 0.],
[-0.5, 0.5, 0.],
[-0.5, -0.5, 0.],
[0.5, -0.5, 0.],
])
# calculate vertices of circular aperture (from +x axis going ccw)
front_circle_vertices = np.zeros((smoothness, 3))
for i in range(smoothness):
angle = 2 * pi * i / smoothness
radial_line = np.array([cos(angle), sin(angle), 0.]) * 0.5
front_circle_vertices[i][:] = radial_line
# The square vertices will be appended to the circular vertices
front_vertices = np.append(front_circle_vertices, square_vertices, 0)
# Create front face of aperture
triangle_indices = []
for i in range(len(front_circle_vertices)):
quadrant = int(4 * float(i) / smoothness)
closest_corner_index = len(front_circle_vertices) + quadrant
triangle_indices.append(
[closest_corner_index, i, (i + 1) % len(front_circle_vertices)])
front_face = GLPolygon(front_vertices, triangle_indices)
# Create back face
back_face = front_face.clone()
back_face.orientation[1] = 180.
back_face.position[2] = 1.
# Create cylinder between faces - starting by creating the circular
# vertices of the back face...
back_circular_vertices = np.array(front_circle_vertices)
back_circular_vertices[:, 2] += 1.
back_circle_start_index = len(front_circle_vertices)
circle_vertices = np.append(front_circle_vertices,
back_circular_vertices,
0)
# ...and now create the cylinder triangles
triangle_indices = []
for front_vertex in range(len(front_circle_vertices)) + [0]:
back_vertex = front_vertex + back_circle_start_index
triangle_indices.extend([front_vertex, back_vertex])
cylinder = GLPolygon.triangle_strip(circle_vertices, triangle_indices)
return CompositePolygon({'front_face': front_face,
'back_face': back_face,
'cylinder': cylinder})
def create_unit_cube():
vertices = np.array([
[0., 0., 0.],
[1., 0., 0.],
[0., 1., 0.],
[1., 1., 0.],
[0., 0., 1.],
[1., 0., 1.],
[0., 1., 1.],
[1., 1., 1.],
])
polygons = {'top': GLPolygon.triangle_strip(vertices, [0, 2, 1, 3]),
'bottom': GLPolygon.triangle_strip(vertices, [4, 5, 6, 7]),
'lower': GLPolygon.triangle_strip(vertices, [0, 1, 4, 5]),
'upper': GLPolygon.triangle_strip(vertices, [2, 6, 3, 7]),
'left': GLPolygon.triangle_strip(vertices, [0, 4, 2, 6]),
'right': GLPolygon.triangle_strip(vertices, [1, 3, 5, 7])}
return CompositePolygon(polygons)
