Datasets:

BackRabb1t
/

LUMEN

---
license: other  # TODO: replace with the actual license, e.g. cc-by-nc-4.0
pretty_name: LUMEN
task_categories:
  - image-to-image
  - depth-estimation
tags:
  - lighting-estimation
  - inverse-rendering
  - hdr
  - environment-map
  - light-probe
  - indoor-scenes
  - synthetic
  - blender
  - siggraph-asia
size_categories:
  - n<1K
---
# LUMEN Dataset

This is the official dataset release of **LUMEN** (SIGGRAPH Asia).

<!-- TODO: fill in -->
[[Paper]](TODO) [[Project Page]](TODO) [[Code]](TODO)

LUMEN is a synthetic indoor-scene dataset for **spatially-varying HDR lighting estimation**. For every procedurally generated indoor scene we provide:

- the original **Blender scene file** (`.blend`);
- multi-view **LDR RGB renderings** with camera intrinsics / extrinsics;
- per-view **depth maps** (EXR);
- **HDR equirectangular environment maps** captured at many **light-probe positions** inside the room, together with the probe positions and rotations.

All coordinates follow the **Blender convention** (right-handed, world **Z-up**; camera looks along its local **-Z**, local **+Y** is up and **+X** is right).

---

## Repository Layout

The repository has **two branches**:

| Branch | Content | Scenes |
| --- | --- | --- |
| [`main`](https://huggingface.co/datasets/BackRabb1t/LUMEN/tree/main) | Blender scene files (`blends/*.blend`) | 392 |
| [`rendered`](https://huggingface.co/datasets/BackRabb1t/LUMEN/tree/rendered) | Rendered RGB, depth and light-probe environment maps | 538 (509 `box_*` + 29 `polygon_*`) |

Scene names are shared across branches, e.g. `blends/box_1012146.blend` on `main` corresponds to `box_1012146/` on `rendered`. Every `.blend` on `main` has a rendered counterpart; some rendered scenes are released without a `.blend` file.

- `box_*`: rooms with a rectangular (box-shaped) floor plan.
- `polygon_*`: rooms with a general polygonal floor plan.

### `main` branch

```
blends/
├── box_1012146.blend
├── box_1016191.blend
└── ...
```

### `rendered` branch

```
<scene_name>/                     # e.g. box_1012146
├── rgb/
│   ├── frame_0001.png            # 512x512, RGBA, 8-bit
│   ├── ...
│   ├── frame_0012.png
│   └── transform.json            # camera intrinsics & extrinsics of every frame
├── depth/
│   ├── depth_0001.exr            # 512x512, single channel 'V', float32
│   ├── ...
│   └── depth_0012.exr
└── env/
    ├── frame0001_envmap01.exr    # 1024x512 equirectangular HDR, RGB float32
    ├── frame0001_envmap02.exr
    ├── ...
    ├── random_envmap0001.exr
    ├── ...
    └── envposition.json          # position & rotation of every light probe
```

- Each scene contains **12 views** (`frame_0001` ... `frame_0012`).
- `depth/depth_XXXX.exr` is aligned pixel-to-pixel with `rgb/frame_XXXX.png`.
- The number of environment maps varies across scenes (typically 20-30), see below.

---

## File Formats

### `rgb/transform.json`

```jsonc
{
  "frames": [
    {
      "frame": "frame_0001",         // -> rgb/frame_0001.png, depth/depth_0001.exr
      "w": 512, "h": 512,            // image resolution
      "fx": 412.0938, "fy": 412.0938,// focal length in pixels
      "cx": 256.0,   "cy": 256.0,    // principal point in pixels
      "c2w": [[...], [...], [...], [0, 0, 0, 1]],  // 4x4 camera-to-world (Blender camera)
      "w2c": [[...], [...], [...], [0, 0, 0, 1]],  // 4x4 world-to-camera, inverse of c2w
      "camera_position": [x, y, z]   // camera center in world space (= c2w[:3, 3])
    },
    ...
  ],
  "hdr_background": {
    "used_hdr": true,                        // whether an outdoor HDRI is used as world background
    "hdr_file": "railway_bridge_02_2k.hdr",  // HDRI file seen through windows / openings
    "strength": 0.4985                       // Blender world background strength
  }
}
```

`c2w` / `w2c` use the **Blender camera convention** (OpenGL-style): the camera looks along **-Z**, **+Y** is up and **+X** is right in camera space. To convert to the OpenCV convention (+Z forward, +Y down), flip the camera Y and Z axes:

```python
c2w_opencv = c2w_blender @ np.diag([1, -1, -1, 1])
```

### `depth/depth_XXXX.exr`
- Single float32 channel named `V`, resolution 512x512, in Blender scene units (meters).
- Pixels with no geometry hit (e.g. seen through a window) have value `1e10`; mask them out before use (e.g. `depth < 1e9`).
### `env/*.exr` (light probes)
- **Equirectangular (lat-long) HDR panoramas**, 1024x512, linear RGB float32 (channels `R`, `G`, `B`).
- Two kinds of probes:
  - `frameXXXX_envmapYY.exr`: the `YY`-th probe associated with view `frame_XXXX`. These probes lie **inside the view frustum** of `frame_XXXX` (they project into `rgb/frame_XXXX.png`), so they can be used as **image-conditioned, spatially-varying lighting ground truth**. Usually 2 per view; a few views have only 1.
  - `random_envmapNNNN.exr`: probes placed at random positions in the room, not tied to any view.

### `env/envposition.json`

A list with one entry per environment map:

```jsonc
[
  {
    "envmap": "frame0001_envmap01",          // -> env/frame0001_envmap01.exr
    "position": "-0.492489, 0.119080, 0.622956",  // probe center in world space (x, y, z), comma-separated string
    "random_rotation_degrees": {             // rotation of the panoramic probe camera, Euler angles in degrees
      "x": 0.0,
      "y": 0.0,
      "z": 126.0244
    }
  },
  ...
]
```

- `position` is in the same Blender world frame as `rgb/transform.json`.
- `random_rotation_degrees` is the (Blender, XYZ Euler) rotation applied to the probe when the panorama was rendered. Undo this rotation if you need the environment map aligned with the world axes.

---

## Download

The dataset is **gated**: please log in and accept the access conditions on the dataset page first, then authenticate with `hf auth login`.

```bash
# All rendered data
hf download BackRabb1t/LUMEN --repo-type dataset --revision rendered --local-dir LUMEN_rendered
# A single rendered scene
hf download BackRabb1t/LUMEN --repo-type dataset --revision rendered \
    --include "box_1012146/*" --local-dir LUMEN_rendered
# All Blender scene files
hf download BackRabb1t/LUMEN --repo-type dataset --revision main --local-dir LUMEN_blend
# A single Blender scene
hf download BackRabb1t/LUMEN blends/box_1012146.blend --repo-type dataset --revision main --local-dir LUMEN_blend
```

Python:

```python
from huggingface_hub import snapshot_download
snapshot_download(
    repo_id="BackRabb1t/LUMEN",
    repo_type="dataset",
    revision="rendered",
    allow_patterns=["box_1012146/*"],
    local_dir="LUMEN_rendered",
)
```

---

## Usage Example

Load one view and project its light probes into the image:

```python
import json
import numpy as np
import imageio.v3 as iio   # pip install imageio[freeimage]  (or use OpenEXR / OpenCV for .exr)
scene = "LUMEN_rendered/box_1012146"
frames = json.load(open(f"{scene}/rgb/transform.json"))["frames"]
probes = json.load(open(f"{scene}/env/envposition.json"))
f = frames[0]                                            # frame_0001
rgb   = iio.imread(f"{scene}/rgb/{f['frame']}.png")      # (512, 512, 4) uint8
depth = iio.imread(f"{scene}/depth/depth_{f['frame'][-4:]}.exr")  # (512, 512) float32
valid = depth < 1e9
w2c = np.array(f["w2c"])
for p in probes:
    if not p["envmap"].startswith("frame" + f["frame"][-4:]):
        continue
    xyz = np.array([float(v) for v in p["position"].split(",")] + [1.0])
    xc, yc, zc = (w2c @ xyz)[:3]                         # Blender camera space, looks along -Z
    u = f["cx"] + f["fx"] * xc / -zc
    v = f["cy"] - f["fy"] * yc / -zc
    envmap = iio.imread(f"{scene}/env/{p['envmap']}.exr")  # (512, 1024, 3) float32, linear HDR
    print(p["envmap"], "pixel:", (u, v), "probe depth:", -zc)
```

---

## Citation

If you find this dataset useful, please cite our paper:

```bibtex
@inproceedings{lumen,
  title     = {TODO},
  author    = {TODO},
  booktitle = {SIGGRAPH Asia Conference Papers},
  year      = {TODO}
}
```

## License

TODO: specify the license and the terms of use. The outdoor HDRIs used as world backgrounds (see `hdr_background.hdr_file`) come from third-party sources (e.g. Poly Haven) and remain under their original licenses.

## Contact

TODO

	---
	license: other # TODO: replace with the actual license, e.g. cc-by-nc-4.0
	pretty_name: LUMEN
	task_categories:
	- image-to-image
	- depth-estimation
	tags:
	- lighting-estimation
	- inverse-rendering
	- hdr
	- environment-map
	- light-probe
	- indoor-scenes
	- synthetic
	- blender
	- siggraph-asia
	size_categories:
	- n<1K
	---

	# LUMEN Dataset

	This is the official dataset release of LUMEN (SIGGRAPH Asia).

	<!-- TODO: fill in -->
	[[Paper]](TODO) [[Project Page]](TODO) [[Code]](TODO)

	LUMEN is a synthetic indoor-scene dataset for spatially-varying HDR lighting estimation. For every procedurally generated indoor scene we provide:

	- the original Blender scene file (`.blend`);
	- multi-view LDR RGB renderings with camera intrinsics / extrinsics;
	- per-view depth maps (EXR);
	- HDR equirectangular environment maps captured at many light-probe positions inside the room, together with the probe positions and rotations.

	All coordinates follow the Blender convention (right-handed, world Z-up; camera looks along its local -Z, local +Y is up and +X is right).

	---

	## Repository Layout

	The repository has two branches:

	\| Branch \| Content \| Scenes \|
	\| --- \| --- \| --- \|
	\| [`main`](https://huggingface.co/datasets/BackRabb1t/LUMEN/tree/main) \| Blender scene files (`blends/*.blend`) \| 392 \|
	\| [`rendered`](https://huggingface.co/datasets/BackRabb1t/LUMEN/tree/rendered) \| Rendered RGB, depth and light-probe environment maps \| 538 (509 `box_` + 29 `polygon_`) \|

	Scene names are shared across branches, e.g. `blends/box_1012146.blend` on `main` corresponds to `box_1012146/` on `rendered`. Every `.blend` on `main` has a rendered counterpart; some rendered scenes are released without a `.blend` file.

	- `box_*`: rooms with a rectangular (box-shaped) floor plan.
	- `polygon_*`: rooms with a general polygonal floor plan.

	### `main` branch

	```
	blends/
	├── box_1012146.blend
	├── box_1016191.blend
	└── ...
	```

	### `rendered` branch

	```
	<scene_name>/ # e.g. box_1012146
	├── rgb/
	│ ├── frame_0001.png # 512x512, RGBA, 8-bit
	│ ├── ...
	│ ├── frame_0012.png
	│ └── transform.json # camera intrinsics & extrinsics of every frame
	├── depth/
	│ ├── depth_0001.exr # 512x512, single channel 'V', float32
	│ ├── ...
	│ └── depth_0012.exr
	└── env/
	├── frame0001_envmap01.exr # 1024x512 equirectangular HDR, RGB float32
	├── frame0001_envmap02.exr
	├── ...
	├── random_envmap0001.exr
	├── ...
	└── envposition.json # position & rotation of every light probe
	```

	- Each scene contains 12 views (`frame_0001` ... `frame_0012`).
	- `depth/depth_XXXX.exr` is aligned pixel-to-pixel with `rgb/frame_XXXX.png`.
	- The number of environment maps varies across scenes (typically 20-30), see below.

	---

	## File Formats

	### `rgb/transform.json`

	```jsonc
	{
	"frames": [
	{
	"frame": "frame_0001", // -> rgb/frame_0001.png, depth/depth_0001.exr
	"w": 512, "h": 512, // image resolution
	"fx": 412.0938, "fy": 412.0938,// focal length in pixels
	"cx": 256.0, "cy": 256.0, // principal point in pixels
	"c2w": [[...], [...], [...], [0, 0, 0, 1]], // 4x4 camera-to-world (Blender camera)
	"w2c": [[...], [...], [...], [0, 0, 0, 1]], // 4x4 world-to-camera, inverse of c2w
	"camera_position": [x, y, z] // camera center in world space (= c2w[:3, 3])
	},
	...
	],
	"hdr_background": {
	"used_hdr": true, // whether an outdoor HDRI is used as world background
	"hdr_file": "railway_bridge_02_2k.hdr", // HDRI file seen through windows / openings
	"strength": 0.4985 // Blender world background strength
	}
	}
	```

	`c2w` / `w2c` use the Blender camera convention (OpenGL-style): the camera looks along -Z, +Y is up and +X is right in camera space. To convert to the OpenCV convention (+Z forward, +Y down), flip the camera Y and Z axes:

	```python
	c2w_opencv = c2w_blender @ np.diag([1, -1, -1, 1])
	```

	### `depth/depth_XXXX.exr`

	- Single float32 channel named `V`, resolution 512x512, in Blender scene units (meters).
	- Pixels with no geometry hit (e.g. seen through a window) have value `1e10`; mask them out before use (e.g. `depth < 1e9`).

	### `env/*.exr` (light probes)

	- Equirectangular (lat-long) HDR panoramas, 1024x512, linear RGB float32 (channels `R`, `G`, `B`).
	- Two kinds of probes:
	- `frameXXXX_envmapYY.exr`: the `YY`-th probe associated with view `frame_XXXX`. These probes lie inside the view frustum of `frame_XXXX` (they project into `rgb/frame_XXXX.png`), so they can be used as image-conditioned, spatially-varying lighting ground truth. Usually 2 per view; a few views have only 1.
	- `random_envmapNNNN.exr`: probes placed at random positions in the room, not tied to any view.

	### `env/envposition.json`

	A list with one entry per environment map:

	```jsonc
	[
	{
	"envmap": "frame0001_envmap01", // -> env/frame0001_envmap01.exr
	"position": "-0.492489, 0.119080, 0.622956", // probe center in world space (x, y, z), comma-separated string
	"random_rotation_degrees": { // rotation of the panoramic probe camera, Euler angles in degrees
	"x": 0.0,
	"y": 0.0,
	"z": 126.0244
	}
	},
	...
	]
	```

	- `position` is in the same Blender world frame as `rgb/transform.json`.
	- `random_rotation_degrees` is the (Blender, XYZ Euler) rotation applied to the probe when the panorama was rendered. Undo this rotation if you need the environment map aligned with the world axes.

	---

	## Download

	The dataset is gated: please log in and accept the access conditions on the dataset page first, then authenticate with `hf auth login`.

	```bash
	# All rendered data
	hf download BackRabb1t/LUMEN --repo-type dataset --revision rendered --local-dir LUMEN_rendered

	# A single rendered scene
	hf download BackRabb1t/LUMEN --repo-type dataset --revision rendered \
	--include "box_1012146/*" --local-dir LUMEN_rendered

	# All Blender scene files
	hf download BackRabb1t/LUMEN --repo-type dataset --revision main --local-dir LUMEN_blend

	# A single Blender scene
	hf download BackRabb1t/LUMEN blends/box_1012146.blend --repo-type dataset --revision main --local-dir LUMEN_blend
	```

	Python:

	```python
	from huggingface_hub import snapshot_download

	snapshot_download(
	repo_id="BackRabb1t/LUMEN",
	repo_type="dataset",
	revision="rendered",
	allow_patterns=["box_1012146/*"],
	local_dir="LUMEN_rendered",
	)
	```

	---

	## Usage Example

	Load one view and project its light probes into the image:

	```python
	import json
	import numpy as np
	import imageio.v3 as iio # pip install imageio[freeimage] (or use OpenEXR / OpenCV for .exr)

	scene = "LUMEN_rendered/box_1012146"

	frames = json.load(open(f"{scene}/rgb/transform.json"))["frames"]
	probes = json.load(open(f"{scene}/env/envposition.json"))

	f = frames[0] # frame_0001
	rgb = iio.imread(f"{scene}/rgb/{f['frame']}.png") # (512, 512, 4) uint8
	depth = iio.imread(f"{scene}/depth/depth_{f['frame'][-4:]}.exr") # (512, 512) float32
	valid = depth < 1e9

	w2c = np.array(f["w2c"])
	for p in probes:
	if not p["envmap"].startswith("frame" + f["frame"][-4:]):
	continue
	xyz = np.array([float(v) for v in p["position"].split(",")] + [1.0])
	xc, yc, zc = (w2c @ xyz)[:3] # Blender camera space, looks along -Z
	u = f["cx"] + f["fx"] * xc / -zc
	v = f["cy"] - f["fy"] * yc / -zc
	envmap = iio.imread(f"{scene}/env/{p['envmap']}.exr") # (512, 1024, 3) float32, linear HDR
	print(p["envmap"], "pixel:", (u, v), "probe depth:", -zc)
	```

	---

	## Citation

	If you find this dataset useful, please cite our paper:

	```bibtex
	@inproceedings{lumen,
	title = {TODO},
	author = {TODO},
	booktitle = {SIGGRAPH Asia Conference Papers},
	year = {TODO}
	}
	```

	## License

	TODO: specify the license and the terms of use. The outdoor HDRIs used as world backgrounds (see `hdr_background.hdr_file`) come from third-party sources (e.g. Poly Haven) and remain under their original licenses.

	## Contact

	TODO