render_by_interp.py

#
# Copyright (C) 2023, Inria
# GRAPHDECO research group, https://team.inria.fr/graphdeco
# All rights reserved.
#
# This software is free for non-commercial, research and evaluation use
# under the terms of the LICENSE.md file.
#
# For inquiries contact  george.drettakis@inria.fr
#

import torch
from scene import Scene
import os
from tqdm import tqdm
from os import makedirs
from gaussian_renderer import render
import torchvision
from utils.general_utils import safe_state
from argparse import ArgumentParser
from arguments import ModelParams, PipelineParams, get_combined_args
from gaussian_renderer import GaussianModel
from utils.pose_utils import get_tensor_from_camera
from utils.camera_utils import generate_interpolated_path
from utils.camera_utils import visualizer
import cv2
import numpy as np
import imageio


def save_interpolate_pose(model_path, iter, n_views):

    org_pose = np.load(model_path + f"pose/pose_{iter}.npy")
    visualizer(org_pose, ["green" for _ in org_pose], model_path + "pose/poses_optimized.png")
    n_interp = int(10 * 30 / n_views)  # 10second, fps=30
    all_inter_pose = []
    for i in range(n_views-1):
        tmp_inter_pose = generate_interpolated_path(poses=org_pose[i:i+2], n_interp=n_interp)
        all_inter_pose.append(tmp_inter_pose)
    all_inter_pose = np.array(all_inter_pose).reshape(-1, 3, 4)

    inter_pose_list = []
    for p in all_inter_pose:
        tmp_view = np.eye(4)
        tmp_view[:3, :3] = p[:3, :3]
        tmp_view[:3, 3] = p[:3, 3]
        inter_pose_list.append(tmp_view)
    inter_pose = np.stack(inter_pose_list, 0)
    visualizer(inter_pose, ["blue" for _ in inter_pose], model_path + "pose/poses_interpolated.png")
    np.save(model_path + "pose/pose_interpolated.npy", inter_pose)


def images_to_video(image_folder, output_video_path, fps=30):
    """
    Convert images in a folder to a video.

    Args:
    - image_folder (str): The path to the folder containing the images.
    - output_video_path (str): The path where the output video will be saved.
    - fps (int): Frames per second for the output video.
    """
    images = []

    for filename in sorted(os.listdir(image_folder)):
        if filename.endswith(('.png', '.jpg', '.jpeg', '.JPG', '.PNG')):
            image_path = os.path.join(image_folder, filename)
            image = imageio.imread(image_path)
            images.append(image)

    imageio.mimwrite(output_video_path, images, fps=fps)


def render_set(model_path, name, iteration, views, gaussians, pipeline, background):
    render_path = os.path.join(model_path, name, "ours_{}".format(iteration), "renders")
    makedirs(render_path, exist_ok=True)

    for idx, view in enumerate(tqdm(views, desc="Rendering progress")):
        camera_pose = get_tensor_from_camera(view.world_view_transform.transpose(0, 1))
        rendering = render(
            view, gaussians, pipeline, background, camera_pose=camera_pose
        )["render"]
        gt = view.original_image[0:3, :, :]
        torchvision.utils.save_image(
            rendering, os.path.join(render_path, "{0:05d}".format(idx) + ".png")
        )


def render_sets(
    dataset: ModelParams,
    iteration: int,
    pipeline: PipelineParams,
    skip_train: bool,
    skip_test: bool,
    args,
):

    # Applying interpolation
    save_interpolate_pose(dataset.model_path, iteration, args.n_views)

    with torch.no_grad():
        gaussians = GaussianModel(dataset.sh_degree)
        scene = Scene(dataset, gaussians, load_iteration=iteration, opt=args, shuffle=False)

        bg_color = [1, 1, 1] if dataset.white_background else [0, 0, 0]
        background = torch.tensor(bg_color, dtype=torch.float32, device="cuda")

    # render interpolated views
    render_set(
        dataset.model_path,
        "interp",
        scene.loaded_iter,
        scene.getTrainCameras(),
        gaussians,
        pipeline,
        background,
    )

    if args.get_video:
        image_folder = os.path.join(dataset.model_path, f'interp/ours_{args.iteration}/renders')
        output_video_file = os.path.join(dataset.model_path, f'{args.scene}_{args.n_views}_view.mp4')
        images_to_video(image_folder, output_video_file, fps=30)


if __name__ == "__main__":
    # Set up command line argument parser
    parser = ArgumentParser(description="Testing script parameters")
    model = ModelParams(parser, sentinel=True)
    pipeline = PipelineParams(parser)
    parser.add_argument("--iteration", default=-1, type=int)
    parser.add_argument("--skip_train", action="store_true")
    parser.add_argument("--skip_test", action="store_true")
    parser.add_argument("--quiet", action="store_true")

    parser.add_argument("--get_video", action="store_true")
    parser.add_argument("--n_views", default=None, type=int)
    parser.add_argument("--scene", default=None, type=str)
    args = get_combined_args(parser)
    print("Rendering " + args.model_path)

    # Initialize system state (RNG)
    # safe_state(args.quiet)

    render_sets(
        model.extract(args),
        args.iteration,
        pipeline.extract(args),
        args.skip_train,
        args.skip_test,
        args,
    )