2021-05-26

from PIL import Image, ImageFont, ImageDraw
from pyquaternion import Quaternion
import open3d as o3d


def text_3d(text, pos, direction=None, degree=0, font=None, font_size=300):
    """
    7 ==>   .......
            .......
               ...
               ...
    Generate a 3D text point cloud used for visualization.
    :param text: content of the text
    :param pos: 3D xyz position of the text upper left corner
    :param direction: 3D normalized direction of where the text faces
    :param degree: in plane rotation of text
    :param font: Name of the font - change it according to your system
    :param font_size: size of the font
    :return: o3d.geoemtry.PointCloud object
    """
    if direction is None:
        direction = (0., 0., 1.)

    font_obj = ImageFont.truetype(font, font_size)
    font_dim = font_obj.getsize(text)

    img = Image.new('RGB', font_dim, color=(255, 255, 255))
    draw = ImageDraw.Draw(img)
    draw.text((0, 0), text, font=font_obj, fill=(0, 0, 0))
    img = np.asarray(img)
    img_mask = img[:, :, 0] < 128
    indices = np.indices([*img.shape[0:2], 1])[:, img_mask, 0].reshape(3, -1).T

    pcd = o3d.geometry.PointCloud()
    pcd.colors = o3d.utility.Vector3dVector(img[img_mask, :].astype(float) / 255.0)
    pcd.points = o3d.utility.Vector3dVector(indices / 100.0)

    raxis = np.cross([0.0, 0.0, 1.0], direction)
    if np.linalg.norm(raxis) < 1e-6:
        raxis = (0.0, 0.0, 1.0)
    trans = (Quaternion(axis=raxis, radians=np.arccos(direction[2])) *
             Quaternion(axis=direction, degrees=degree)).transformation_matrix
    trans[0:3, 3] = np.asarray(pos)
    pcd.transform(trans)
    return pcd


if __name__ == '__main__':
    # 调用方式
    text_point_cloud = text_3d('text', font='./fonts/casy_cz.ttf', pos=[0, 0, 0],
                               direction=[0., 0., 1.0], degree=-90)