import numpy as np from math import cos, sin from collections import namedtuple ColorGrid = namedtuple("ColorGrid", ["positions", "colors"]) def build_color_grid(x_count=10, y_count=10, z_count=10, twist=0): """ Create a cube of points with colors. The total point cloud will have x_count * y_count * z_count points. Parameters ---------- x_count, y_count, z_count: Number of points in each dimension. twist: Angle to twist from bottom to top of the cube """ grid = np.mgrid[ slice(-x_count, x_count, x_count * 1j), slice(-y_count, y_count, y_count * 1j), slice(-z_count, z_count, z_count * 1j), ] angle = np.linspace(-float(twist) / 2, float(twist) / 2, z_count) for z in range(z_count): xv, yv, zv = grid[:, :, :, z] rot_xv = xv * cos(angle[z]) - yv * sin(angle[z]) rot_yv = xv * sin(angle[z]) + yv * cos(angle[z]) grid[:, :, :, z] = [rot_xv, rot_yv, zv] positions = np.vstack([xyz.ravel() for xyz in grid]) colors = np.vstack( [ xyz.ravel() for xyz in np.mgrid[ slice(0, 255, x_count * 1j), slice(0, 255, y_count * 1j), slice(0, 255, z_count * 1j), ] ] ) return ColorGrid(positions.T, colors.T.astype(np.uint8))