| # DONUT (Dataset Of MaNifold strUcTures) |
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| This repository contains a dataset of 3D samples made of watertight meshes and corresponding point clouds. Each sample is composed of one or several watertight mesh components and one 8192-point cloud representation. |
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| The dataset contains **29,517 samples** in total. |
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| ## Overview |
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| The figure below shows a few samples from the dataset together with their labels. |
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| ## Contents |
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| The repository is organized as follows: |
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| ```text |
| . |
| ├── metadata.csv |
| ├── obj/ |
| │ ├── shard_0/ |
| │ ├── shard_1/ |
| │ └── shard_2/ |
| └── pcd/ |
| ├── shard_0/ |
| ├── shard_1/ |
| └── shard_2/ |
| ``` |
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| - `obj/` contains the mesh files as `.npz` archives. |
| - `pcd/` contains the point clouds as `.npy` files. |
| - `metadata.csv` contains one row per sample with topological metadata. |
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| There are **29,517** mesh files in `obj/` and **29,517** point cloud files in `pcd/`. |
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| ## File Format |
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| ### Meshes |
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| Each mesh sample is stored as an `.npz` file in `obj/`. The archive contains: |
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| - `vertices.npy` |
| - `faces.npy` |
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| A sample may contain one or several watertight connected mesh components. |
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| ### Point Clouds |
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| Each point cloud sample is stored as a `.npy` file in `pcd/`. |
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| Each point cloud contains **8192 points** and corresponds to the sample with the same `id`. |
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| ## Sample Identification |
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| Each sample is identified by a unique `id` string. |
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| The same `id` is used in: |
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| - the filename in `obj/` |
| - the filename in `pcd/` |
| - the `id` column in `metadata.csv` |
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| For example, if a sample has id `abc123`, its files are: |
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| - `obj/.../abc123.npz` |
| - `pcd/.../abc123.npy` |
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| ## Metadata |
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| `metadata.csv` contains the following columns: |
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| - `id`: unique identifier of the sample |
| - `genus`: total number of holes across all mesh components in the sample |
| - `components`: total number of connected mesh components in the sample |
| - `sample_code`: array of 6 integers describing how many components of each genus are present |
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| ## Meaning of `sample_code` |
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| `sample_code` is an array of 6 integers: |
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| ```text |
| [n0, n1, n2, n3, n4, n5] |
| ``` |
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| Here, `ni` is the number of mesh components in the sample whose genus is `i`. |
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| So: |
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| - `n0` is the number of genus-0 components |
| - `n1` is the number of genus-1 components |
| - `n2` is the number of genus-2 components |
| - `n3` is the number of genus-3 components |
| - `n4` is the number of genus-4 components |
| - `n5` is the number of genus-5 components |
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| From `sample_code`, the metadata values are computed as: |
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| ```text |
| genus = sum(i * ni for i in [0, 1, 2, 3, 4, 5]) |
| components = sum(ni for i in [0, 1, 2, 3, 4, 5]) |
| ``` |
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| In other words: |
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| - `genus` is the total number of holes in the full sample |
| - `components` is the total number of connected components in the full sample |
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| The distribution of labels in the dataset is shown below. |
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| ## Examples |
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| ```text |
| sample_code = [2, 1, 0, 0, 0, 0] |
| ``` |
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| This means: |
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| - 2 components of genus 0 |
| - 1 component of genus 1 |
| - total genus = 0 * 2 + 1 * 1 = 1 |
| - total components = 2 + 1 = 3 |
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| ## Summary |
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| DONUT is a dataset of **29,517** samples of manifold 3D structures. |
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| Each sample provides: |
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| - one mesh file in `.npz` format |
| - one 8192-point cloud in `.npy` format |
| - one metadata entry in `metadata.csv` |
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| The metadata describes the global topology of each sample through its total genus, number of connected components, and component-wise genus distribution. |
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