util/vis.py

import os
import cv2
import numpy as np
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import matplotlib as mpl
import os
os.environ['PYOPENGL_PLATFORM'] = 'egl'
import pyrender
import trimesh
from config.config import cfg


def vis_keypoints_with_skeleton(img, kps, kps_lines, kp_thresh=0.4, alpha=1):
    # Convert from plt 0-1 RGBA colors to 0-255 BGR colors for opencv.
    cmap = plt.get_cmap('rainbow')
    colors = [cmap(i) for i in np.linspace(0, 1, len(kps_lines) + 2)]
    colors = [(c[2] * 255, c[1] * 255, c[0] * 255) for c in colors]

    # Perform the drawing on a copy of the image, to allow for blending.
    kp_mask = np.copy(img)

    # Draw the keypoints.
    for l in range(len(kps_lines)):
        i1 = kps_lines[l][0]
        i2 = kps_lines[l][1]
        p1 = kps[0, i1].astype(np.int32), kps[1, i1].astype(np.int32)
        p2 = kps[0, i2].astype(np.int32), kps[1, i2].astype(np.int32)
        if kps[2, i1] > kp_thresh and kps[2, i2] > kp_thresh:
            cv2.line(kp_mask,
                     p1,
                     p2,
                     color=colors[l],
                     thickness=2,
                     lineType=cv2.LINE_AA)
        if kps[2, i1] > kp_thresh:
            cv2.circle(kp_mask,
                       p1,
                       radius=3,
                       color=colors[l],
                       thickness=-1,
                       lineType=cv2.LINE_AA)
        if kps[2, i2] > kp_thresh:
            cv2.circle(kp_mask,
                       p2,
                       radius=3,
                       color=colors[l],
                       thickness=-1,
                       lineType=cv2.LINE_AA)

    # Blend the keypoints.
    return cv2.addWeighted(img, 1.0 - alpha, kp_mask, alpha, 0)


def vis_keypoints(img, kps, alpha=1, radius=3, color=None):
    # Convert from plt 0-1 RGBA colors to 0-255 BGR colors for opencv.
    cmap = plt.get_cmap('rainbow')
    if color is None:
        colors = [cmap(i) for i in np.linspace(0, 1, len(kps) + 2)]
        colors = [(c[2] * 255, c[1] * 255, c[0] * 255) for c in colors]

    # Perform the drawing on a copy of the image, to allow for blending.
    kp_mask = np.copy(img)

    # Draw the keypoints.
    for i in range(len(kps)):
        p = kps[i][0].astype(np.int32), kps[i][1].astype(np.int32)
        if color is None:
            cv2.circle(kp_mask,
                       p,
                       radius=radius,
                       color=colors[i],
                       thickness=-1,
                       lineType=cv2.LINE_AA)
        else:
            cv2.circle(kp_mask,
                       p,
                       radius=radius,
                       color=color,
                       thickness=-1,
                       lineType=cv2.LINE_AA)

    # Blend the keypoints.
    return cv2.addWeighted(img, 1.0 - alpha, kp_mask, alpha, 0)


def vis_mesh(img, mesh_vertex, alpha=0.5):
    # Convert from plt 0-1 RGBA colors to 0-255 BGR colors for opencv.
    cmap = plt.get_cmap('rainbow')
    colors = [cmap(i) for i in np.linspace(0, 1, len(mesh_vertex))]
    colors = [(c[2] * 255, c[1] * 255, c[0] * 255) for c in colors]

    # Perform the drawing on a copy of the image, to allow for blending.
    mask = np.copy(img)

    # Draw the mesh
    for i in range(len(mesh_vertex)):
        p = mesh_vertex[i][0].astype(np.int32), mesh_vertex[i][1].astype(
            np.int32)
        cv2.circle(mask,
                   p,
                   radius=1,
                   color=colors[i],
                   thickness=-1,
                   lineType=cv2.LINE_AA)

    # Blend the keypoints.
    return cv2.addWeighted(img, 1.0 - alpha, mask, alpha, 0)


def vis_3d_skeleton(kpt_3d, kpt_3d_vis, kps_lines, filename=None):

    fig = plt.figure()
    ax = fig.add_subplot(111, projection='3d')

    # Convert from plt 0-1 RGBA colors to 0-255 BGR colors for opencv.
    cmap = plt.get_cmap('rainbow')
    colors = [cmap(i) for i in np.linspace(0, 1, len(kps_lines) + 2)]
    colors = [np.array((c[2], c[1], c[0])) for c in colors]

    for l in range(len(kps_lines)):
        i1 = kps_lines[l][0]
        i2 = kps_lines[l][1]
        x = np.array([kpt_3d[i1, 0], kpt_3d[i2, 0]])
        y = np.array([kpt_3d[i1, 1], kpt_3d[i2, 1]])
        z = np.array([kpt_3d[i1, 2], kpt_3d[i2, 2]])

        if kpt_3d_vis[i1, 0] > 0 and kpt_3d_vis[i2, 0] > 0:
            ax.plot(x, z, -y, c=colors[l], linewidth=2)
        if kpt_3d_vis[i1, 0] > 0:
            ax.scatter(kpt_3d[i1, 0],
                       kpt_3d[i1, 2],
                       -kpt_3d[i1, 1],
                       c=colors[l],
                       marker='o')
        if kpt_3d_vis[i2, 0] > 0:
            ax.scatter(kpt_3d[i2, 0],
                       kpt_3d[i2, 2],
                       -kpt_3d[i2, 1],
                       c=colors[l],
                       marker='o')

    x_r = np.array([0, cfg.input_shape[1]], dtype=np.float32)
    y_r = np.array([0, cfg.input_shape[0]], dtype=np.float32)
    z_r = np.array([0, 1], dtype=np.float32)

    if filename is None:
        ax.set_title('3D vis')
    else:
        ax.set_title(filename)

    ax.set_xlabel('X Label')
    ax.set_ylabel('Z Label')
    ax.set_zlabel('Y Label')
    ax.legend()

    plt.show()
    cv2.waitKey(0)


def save_obj(v, f, file_name='output.obj'):
    obj_file = open(file_name, 'w')
    for i in range(len(v)):
        obj_file.write('v ' + str(v[i][0]) + ' ' + str(v[i][1]) + ' ' +
                       str(v[i][2]) + '\n')
    for i in range(len(f)):
        obj_file.write('f ' + str(f[i][0] + 1) + '/' + str(f[i][0] + 1) + ' ' +
                       str(f[i][1] + 1) + '/' + str(f[i][1] + 1) + ' ' +
                       str(f[i][2] + 1) + '/' + str(f[i][2] + 1) + '\n')
    obj_file.close()


def perspective_projection(vertices, cam_param):
    # vertices: [N, 3]
    # cam_param: [3]
    fx, fy = cam_param['focal']
    cx, cy = cam_param['princpt']
    vertices[:, 0] = vertices[:, 0] * fx / vertices[:, 2] + cx
    vertices[:, 1] = vertices[:, 1] * fy / vertices[:, 2] + cy
    return vertices


def render_mesh(img, mesh, face, cam_param, mesh_as_vertices=False):
    if mesh_as_vertices:
        # to run on cluster where headless pyrender is not supported for A100/V100
        vertices_2d = perspective_projection(mesh, cam_param)
        img = vis_keypoints(img,
                            vertices_2d,
                            alpha=0.8,
                            radius=2,
                            color=(0, 0, 255))
    else:
        # mesh
        mesh = trimesh.Trimesh(mesh, face)
        rot = trimesh.transformations.rotation_matrix(np.radians(180),
                                                      [1, 0, 0])
        mesh.apply_transform(rot)
        material = pyrender.MetallicRoughnessMaterial(
            metallicFactor=0.0,
            alphaMode='OPAQUE',
            baseColorFactor=(1.0, 1.0, 0.9, 1.0))
        mesh = pyrender.Mesh.from_trimesh(mesh,
                                          material=material,
                                          smooth=False)
        scene = pyrender.Scene(ambient_light=(0.3, 0.3, 0.3))
        scene.add(mesh, 'mesh')

        focal, princpt = cam_param['focal'], cam_param['princpt']
        camera = pyrender.IntrinsicsCamera(fx=focal[0],
                                           fy=focal[1],
                                           cx=princpt[0],
                                           cy=princpt[1])
        scene.add(camera)

        # renderer
        renderer = pyrender.OffscreenRenderer(viewport_width=img.shape[1],
                                              viewport_height=img.shape[0],
                                              point_size=1.0)

        # light
        light = pyrender.DirectionalLight(color=[1.0, 1.0, 1.0], intensity=0.8)
        light_pose = np.eye(4)
        light_pose[:3, 3] = np.array([0, -1, 1])
        scene.add(light, pose=light_pose)
        light_pose[:3, 3] = np.array([0, 1, 1])
        scene.add(light, pose=light_pose)
        light_pose[:3, 3] = np.array([1, 1, 2])
        scene.add(light, pose=light_pose)

        # render
        rgb, depth = renderer.render(scene, flags=pyrender.RenderFlags.RGBA)
        rgb = rgb[:, :, :3].astype(np.float32)
        valid_mask = (depth > 0)[:, :, None]

        # save to image
        img = rgb * valid_mask + img * (1 - valid_mask)

    return img