projet-probleme-inverse-3D/src/draw.py

import matplotlib.pyplot as plt
import numpy as np


def f(x, y):
    return np.exp(-((x**2) + y**2) / 3)


x_vals = np.linspace(-5, 5, 100)
y_vals = np.linspace(-5, 5, 100)


X, Y = np.meshgrid(x_vals, y_vals)

Z = f(X - 2, Y) + f(X + 2, Y)
Z = (Z > 0.4).astype(np.float32)
Z *= np.random.rand(*Z.shape)


for i, x in enumerate(x_vals):
    for j, y in enumerate(y_vals):
        color = f"{hex(int(Z[j, i] * 255))[2:]}"
        if color == "0":
            color = "#f00"
        else:
            color = "#" + 3 * color
        plt.fill([x, x + 0.1, x + 0.1, x], [y, y, y + 0.1, y + 0.1], color=color)


nb_cams = 32
cam_poses = np.array(
    [[6 * np.cos(theta), 6 * np.sin(theta)] for theta in np.linspace(0, 2 * np.pi, nb_cams, endpoint=False)]
)
cam_rots = np.linspace(np.pi, 3 * np.pi, nb_cams, endpoint=False)
cam2world_projs = np.array(
    [
        [[np.cos(theta), -np.sin(theta), cam_pose[0]], [np.sin(theta), np.cos(theta), cam_pose[1]], [0, 0, 1]]
        for theta, cam_pose in zip(cam_rots, cam_poses)
    ]
)

for i in range(nb_cams):
    plt.plot(cam_poses[i][0], cam_poses[i][1], "ro")
    plt.text(cam_poses[i][0], cam_poses[i][1], str(i))
    x = np.array([[0, 0, 1], [0.5, -0.2, 1], [0.5, 0.2, 1], [0, 0, 1]]).T
    x = cam2world_projs[i] @ x
    x /= x[2, :]
    plt.plot(x[0, :], x[1, :], "r-")


plt.xlim(-7, 7)
plt.ylim(-7, 7)
plt.axis("equal")


# draw 1d image of the scene for each camera
for i in range(2):
    plt.figure()
    # sort pixels by distance to camera
    cam_pose = cam_poses[i]
    pixels_dist = np.linalg.norm(np.array([X.flatten(), Y.flatten()]).T - cam_pose, axis=1)
    pixels_sort = np.argsort(pixels_dist)[::-1]

    px = np.array([[-5, -5, 1], [5, -5, 1], [5, 5, 1], [-5, 5, 1]]).T
    px = np.linalg.inv(cam2world_projs[i]) @ px
    px /= px[1, :]

    x0 = px[1, :].min()
    x1 = px[1, :].max()

    plt.fill([x0, x1, x1, x0], [0, 0, 1, 1], color="r")

    for j in pixels_sort:
        x, y = X.flatten()[j], Y.flatten()[j]
        color = f"{hex(int(Z.flatten()[j] * 255))[2:]}"
        if color == "0":
            continue
        color = "#" + 3 * color

        px = np.array([[x, y, 1], [x + 0.1, y, 1], [x + 0.1, y + 0.1, 1], [x, y + 0.1, 1]]).T
        px = np.linalg.inv(cam2world_projs[i]) @ px
        px /= px[1, :]

        x0 = px[1, :].min()
        x1 = px[1, :].max()

        plt.fill([x0, x1, x1, x0], [0, 0, 1, 1], color=color)
    plt.axis("equal")

plt.show()