indoor_house/bpy_render_views.py

import argparse
import os
import json
from math import radians
import bpy
import numpy as np

COLOR_SPACES = ["display", "linear"]
DEVICES = ["cpu", "cuda", "optix"]

def listify_matrix(matrix):
    matrix_list = []
    for row in matrix:
        matrix_list.append(list(row))
    return matrix_list

def parent_obj_to_camera(b_camera, origin):
    b_empty = bpy.data.objects.new("Empty", None)
    b_empty.location = origin
    b_camera.parent = b_empty

    scn = bpy.context.scene
    scn.collection.objects.link(b_empty)
    bpy.context.view_layer.objects.active = b_empty

    return b_empty

def main(args):
    bpy.ops.wm.open_mainfile(filepath=args.blend_path)

    scene = bpy.data.scenes["Scene"]
    scene.render.engine = "CYCLES"
    scene.render.use_persistent_data = True
    scene.cycles.samples = 256
    bpy.context.scene.unit_settings.scale_length = 0.01
    if args.device == "cpu":
        bpy.context.preferences.addons["cycles"].preferences.compute_device_type = "NONE"
        bpy.context.scene.cycles.device = "CPU"
    elif args.device == "cuda":
        bpy.context.preferences.addons["cycles"].preferences.compute_device_type = "CUDA"
        bpy.context.scene.cycles.device = "GPU"
    elif args.device == "optix":
        bpy.context.preferences.addons["cycles"].preferences.compute_device_type = "OPTIX"
        bpy.context.scene.cycles.device = "GPU"
    bpy.context.preferences.addons["cycles"].preferences.get_devices()
    
    scene.view_layers[0].use_pass_combined = True
    scene.use_nodes = True
    tree = scene.node_tree

    if args.depth:
        scene.view_layers[0].use_pass_z = True
        combine_color = tree.nodes.new("CompositorNodeCombineColor")
        depth_output = tree.nodes.new("CompositorNodeOutputFile")
    if args.normal:
        scene.view_layers[0].use_pass_normal = True
        normal_output = tree.nodes.new("CompositorNodeOutputFile")
    if args.depth or args.normal:
        render_layers = tree.nodes.new("CompositorNodeRLayers")

    scene.render.filepath = args.renders_path
    scene.render.use_file_extension = True
    scene.render.use_overwrite = True
    scene.render.image_settings.color_mode = "RGBA"

    if args.color_space == "display":
        scene.render.image_settings.file_format = "PNG"
        scene.render.image_settings.color_depth = "8"
        scene.render.image_settings.color_management = "FOLLOW_SCENE"
    elif args.color_space == "linear":
        scene.render.image_settings.file_format = "OPEN_EXR"
        scene.render.image_settings.color_depth = "32"

    if args.depth:
        depth_output.base_path = os.path.join(args.renders_path, "depth")
        depth_output.file_slots[0].use_node_format = True
        scene.frame_set(0)

        depth_output.format.file_format = "OPEN_EXR"
        depth_output.format.color_mode = "RGB"
        depth_output.format.color_depth = "32"
        depth_output.format.exr_codec = "NONE"

        links = tree.links
        combine_color.mode = "RGB"
        links.new(render_layers.outputs["Depth"], combine_color.inputs["Red"])
        combine_color.inputs["Green"].default_value = 0
        combine_color.inputs["Blue"].default_value = 0
        combine_color.inputs["Alpha"].default_value = 1

        links.new(combine_color.outputs["Image"], depth_output.inputs["Image"])

    if args.normal:
        normal_output.base_path = os.path.join(args.renders_path, "normal")
        normal_output.file_slots[0].use_node_format = True
        scene.frame_set(0)

        normal_output.format.file_format = "OPEN_EXR"
        normal_output.format.color_mode = "RGB"
        normal_output.format.color_depth = "32"
        normal_output.format.exr_codec = "NONE"

        links = tree.links
        combine_color.mode = "RGB"
        links.new(render_layers.outputs["Normal"], normal_output.inputs["Image"])

    scene.render.dither_intensity = 0.0
    scene.render.film_transparent = True
    scene.render.resolution_percentage = 100                                                                                                                                                                                            
    scene.render.resolution_x = args.resolution[0]
    scene.render.resolution_y = args.resolution[1]

    cam = bpy.data.objects["Camera"]
    cam.location = (4.0, -214.736, 120.0)
    cam.rotation_mode = "XYZ"
    cam_constraint = cam.constraints.new(type="TRACK_TO")
    cam_constraint.track_axis = "TRACK_NEGATIVE_Z"
    cam_constraint.up_axis = "UP_Y"
    b_empty = parent_obj_to_camera(cam, (0, 0, 100.0))
    cam_constraint.target = b_empty

    args.renders_path = os.path.normpath(args.renders_path)
    folder_name = os.path.basename(args.renders_path)
    renders_parent_path = os.path.dirname(args.renders_path)
    transforms_path = os.path.join(renders_parent_path, f"transforms_{folder_name}.json")

    stepsize = 360.0 / args.num_views
    out_data = {
        "camera_angle_x": cam.data.angle_x,
        "frames": []
    }

    for i in range(args.num_views):
        if args.random_views:
            if args.upper_views:
                # 从上半球随机采样视图
                # 限制 x 轴（pitch）的旋转范围以避免向下拍摄
                pitch = radians(np.random.uniform(-20.0 , 30.0))  # 限制俯仰角在 0 到 90 度之间
                yaw = radians(np.random.uniform(0, 360))   # 随机偏航角
                b_empty.rotation_euler = (pitch, 0, yaw)
            else:
                # 完全随机采样视图
                b_empty.rotation_euler = (
                    radians(np.random.uniform(0, 180)),
                    0,
                    radians(np.random.uniform(0, 360))
                )
        else:
            # 等间隔采样视图
            b_empty.rotation_euler[2] = radians(i * stepsize)

        scene.render.filepath = os.path.join(args.renders_path, f"r_{i}")
        if args.depth:
            depth_output.file_slots[0].path = f"r_{i}"
        if args.normal:
            normal_output.file_slots[0].path = f"r_{i}"
        bpy.ops.render.render(write_still=True)

        if args.depth:
            os.rename(os.path.join(depth_output.base_path, f"r_{i}0000.exr"),
                      os.path.join(depth_output.base_path, f"r_{i}.exr"))
        if args.normal:
            os.rename(os.path.join(normal_output.base_path, f"r_{i}0000.exr"),
                      os.path.join(normal_output.base_path, f"r_{i}.exr"))

        frame_data = {
            "file_path": os.path.join(".", os.path.relpath(scene.render.filepath, start=renders_parent_path)),
            "rotation": radians(i * stepsize),
            "transform_matrix": listify_matrix(cam.matrix_world)
        }
        out_data["frames"].append(frame_data)

    with open(transforms_path, "w") as out_file:
        json.dump(out_data, out_file, indent=4)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Script for rendering novel views of synthetic Blender scenes.")
    parser.add_argument("blend_path", type=str, help="Path to the blend-file of the synthetic Blender scene.")
    parser.add_argument("renders_path", type=str, help="Desired path to the novel view renders.")
    parser.add_argument("num_views", type=int, help="Number of novel view renders.")
    parser.add_argument("resolution", type=int, nargs=2, default=[1080, 720], help="Image resolution of the novel view renders.")
    parser.add_argument("--color_space", type=str, choices=COLOR_SPACES, default="display", help="Color space of the output novel view images.")
    parser.add_argument("--device", type=str, choices=DEVICES, default="cuda", help="Compute device type for rendering.")
    parser.add_argument("--random_views", action="store_true", help="Randomly sample novel views.")
    parser.add_argument("--upper_views", action="store_true", help="Only sample novel views from the upper hemisphere.")
    parser.add_argument("--depth", action="store_true", help="Render depth maps too.")
    parser.add_argument("--normal", action="store_true", help="Render normal maps too.")
    args = parser.parse_args()

    main(args)

# bpy.context.scene.unit_settings.scale_length = 0.01