terrain.py

import noise
import numpy as np
import pybullet as p


class Terrain:
    def __init__(self):
        """
        Make the terrain
        """

        rows, cols = 16, 16
        lateral_scale = 2
        vertical_scale = 8

        self.heightmap = np.zeros((cols, rows), dtype=float)
        for x in range(cols):
            for y in range(rows):
                # Perlin needs inputs between 0 and 1
                # We also need to scale as it outputs between -1 and 1
                self.heightmap[x, y] = vertical_scale * noise.pnoise2(
                    x / cols / lateral_scale, y / rows / lateral_scale,
                    octaves=6, persistence=0.5, lacunarity=2.0, base=0,
                )

        self.terrain_shape = p.createCollisionShape(
            shapeType=p.GEOM_HEIGHTFIELD, heightfieldData=self.heightmap.T.reshape(-1),
            heightfieldTextureScaling=rows - 1,
            numHeightfieldRows=rows, numHeightfieldColumns=cols,
        )
        self.terrain_multi_body = p.createMultiBody(0, self.terrain_shape)

        # Precompute normals
        # self.normals = np.zeros((cols, rows, 3), dtype=float)
        # for x in range(1, cols):
        #     for y in range(1, rows):
        #         # Shoot a ray from the sky directly above this cell and collect the hit normal
        #         # I figured this would be most similar to the snake giving back normal values from contact
        #         x_c = x - cols / 2
        #         y_c = y - rows / 2
        #         hit, = client.rayTest([x_c, y_c, 100], [x_c, y_c, -100])
        #         hit_normal = hit[4]
        #         self.normals[x, y] = hit_normal
        #         point = np.array([x_c, y_c, self.heightmap[x, y]])
        #         client.addUserDebugLine(point, point + hit_normal, [1, 0, 0])