File size: 5,079 Bytes
cb8518a | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 | from __future__ import annotations
import argparse
import json
import sys
from pathlib import Path
import bpy
import numpy as np
def parse_args() -> argparse.Namespace:
argv_source = getattr(bpy.app, "argv", None)
if argv_source is None:
argv_source = sys.argv
argv: list[str] = []
if "--" in argv_source:
argv = argv_source[argv_source.index("--") + 1 :]
parser = argparse.ArgumentParser(description="Extract camera pose and approximate depth from a scene")
parser.add_argument("--input", required=True, help="Input .blend/.glb/.gltf scene")
parser.add_argument("--output_dir", required=True, help="Output directory for camera.json and depth.npy")
parser.add_argument("--frame", type=int, default=None, help="Frame to evaluate; default scene.frame_start")
parser.add_argument("--max_depth_samples", type=int, default=300000)
parser.add_argument("--seed", type=int, default=42)
return parser.parse_args(argv)
def load_input_scene(input_path: str) -> Path:
path = Path(input_path).resolve()
if not path.exists():
raise FileNotFoundError(f"Input scene does not exist: {path}")
ext = path.suffix.lower()
if ext == ".blend":
bpy.ops.wm.open_mainfile(filepath=str(path))
elif ext in {".glb", ".gltf"}:
bpy.ops.object.select_all(action="SELECT")
bpy.ops.object.delete()
bpy.ops.import_scene.gltf(filepath=str(path))
else:
raise ValueError(f"Unsupported input scene extension: {path.suffix}")
return path
def pick_camera(scene: bpy.types.Scene) -> bpy.types.Object:
if scene.camera is not None:
return scene.camera
cameras = [obj for obj in scene.objects if obj.type == "CAMERA"]
if not cameras:
raise FileNotFoundError("Scene has no camera; cannot auto-extract camera/depth metadata.")
return cameras[0]
def world_vertices(obj_eval: bpy.types.Object, mesh: bpy.types.Mesh) -> np.ndarray:
local = np.empty(len(mesh.vertices) * 3, dtype=np.float32)
mesh.vertices.foreach_get("co", local)
local = local.reshape(-1, 3)
mat = np.array(obj_eval.matrix_world, dtype=np.float32)
rot = mat[:3, :3]
trans = mat[:3, 3]
return (local @ rot.T + trans).astype(np.float32, copy=False)
def collect_depths(scene: bpy.types.Scene, camera: bpy.types.Object, max_samples: int, seed: int) -> np.ndarray:
depsgraph = bpy.context.evaluated_depsgraph_get()
w2c = np.array(camera.matrix_world.inverted(), dtype=np.float64)
depths: list[np.ndarray] = []
for obj in scene.objects:
if obj.type != "MESH" or obj.hide_render:
continue
obj_eval = obj.evaluated_get(depsgraph)
mesh = obj_eval.to_mesh(preserve_all_data_layers=False, depsgraph=depsgraph)
if mesh is None:
continue
try:
if len(mesh.vertices) == 0:
continue
verts = world_vertices(obj_eval, mesh).astype(np.float64)
cam = verts @ w2c[:3, :3].T + w2c[:3, 3]
depth = -cam[:, 2]
depth = depth[np.isfinite(depth) & (depth > 1e-8)]
if depth.size:
depths.append(depth.astype(np.float32, copy=False))
finally:
obj_eval.to_mesh_clear()
if not depths:
return np.zeros((0,), dtype=np.float32)
values = np.concatenate(depths, axis=0)
if max_samples > 0 and values.size > max_samples:
rng = np.random.default_rng(seed)
idx = rng.choice(values.size, size=max_samples, replace=False)
values = values[idx]
return values.astype(np.float32, copy=False)
def main() -> None:
args = parse_args()
scene_path = load_input_scene(args.input)
scene = bpy.context.scene
frame = int(args.frame) if args.frame is not None else int(scene.frame_start)
scene.frame_set(frame)
camera = pick_camera(scene)
camera_to_world = np.array(camera.matrix_world, dtype=np.float64)
world_to_camera = np.array(camera.matrix_world.inverted(), dtype=np.float64)
depths = collect_depths(scene, camera, args.max_depth_samples, args.seed)
output_dir = Path(args.output_dir).resolve()
output_dir.mkdir(parents=True, exist_ok=True)
depth_path = output_dir / "depth.npy"
camera_path = output_dir / "camera.json"
np.save(depth_path, depths)
payload = {
"scene": str(scene_path),
"frame": frame,
"camera_name": camera.name,
"world_to_camera": world_to_camera.tolist(),
"camera_to_world": camera_to_world.tolist(),
"depth_path": str(depth_path),
"depth_count": int(depths.size),
"depth_median": float(np.median(depths)) if depths.size else None,
"depth_definition": "positive mesh vertex depth in Blender camera coordinates, depth=-z_camera",
}
camera_path.write_text(json.dumps(payload, indent=2, ensure_ascii=False) + "\n", encoding="utf-8")
print(json.dumps({"camera": str(camera_path), "depth": str(depth_path), "depth_count": int(depths.size)}))
if __name__ == "__main__":
main()
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