Mesh To GIF

This script creates a .gif animation of a mesh following the provided camera trajectories.

Code

import sys
import os
import argparse
from tqdm import tqdm

import cv2
import numpy as np
import imageio

import open3d as o3d
import open3d.visualization.rendering as rendering

from cvt.io import read_mesh, read_cams_sfm
from cvt.geometry import project_renderer

# argument parsing
parse = argparse.ArgumentParser(description="Mesh-Video generator.")
parse.add_argument("-m", "--mesh", default="mesh.ply", type=str,
        help="Input mesh to be captured in video.")
parse.add_argument("-o", "--output_path", default="images/", type=str,
        help="Output directory where all frames of the video will be stored.")
parse.add_argument("-c", "--camera_path", default="cameras/", type=str,
        help="Input path to the directory where the camera information is stored.")
parse.add_argument("-v", "--video_file", default="", type=str,
        help="The name of the output video file (with extension). This will be stored in the output path (ex: mesh_vid.gif)")
parse.add_argument("-w", "--width", default=1600, type=int,
        help="The desired image width.")
parse.add_argument("-t", "--height", default=1200, type=int,
        help="The desired image height.")
parse.add_argument("-f", "--fps", default=8, type=int,
        help="The desired frame rate for the captured video.")
parse.add_argument("-s", "--offset_index", default=0, type=int,
        help="The desired frame index to begin the gif animation.")
parse.add_argument("-n", "--total_frames", default=8, type=int,
        help="The desired number of frames to include in the animation (loops forward and backward through the frames).")
ARGS = parse.parse_args()


def main():
    if not os.path.exists(ARGS.output_path):
        os.mkdir(ARGS.output_path)

    # load in data
    mesh = read_mesh(ARGS.mesh)
    cams = read_cams_sfm(ARGS.camera_path)

    # set up the renderer
    render = o3d.visualization.rendering.OffscreenRenderer(ARGS.width, ARGS.height)
    mat = o3d.visualization.rendering.MaterialRecord()
    mat.shader = 'defaultUnlit'
    render.scene.add_geometry("mesh", mesh, mat)
    render.scene.set_background(np.asarray([0,0,0,1])) #r,g,b,a
    video_file = os.path.join(ARGS.output_path, ARGS.video_file)

    # compute list of indices
    indices = list(range(0,ARGS.total_frames,1)) + list(range(ARGS.total_frames,0,-1))

    # animate scene
    with imageio.get_writer(video_file, mode="I", fps=ARGS.fps) as writer:
        for view_num in tqdm(indices):
            # get camera for current view
            cam = cams[ARGS.offset_index + view_num]

            # project to image
            image = project_renderer(render, cam[1], cam[0], ARGS.width, ARGS.height)
            image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)

            # write image to gif
            writer.append_data(image)

if __name__=="__main__":
    main()