--- pretty_name: Sking language: - en license: agpl-3.0 task_categories: - text-to-image - image-to-image tags: - minecraft - 3d - voxel - minecraft-skin - texture - dataset-generation --- # Sking: Minecraft Skin 3D Rendering & Dataset Preprocessing Pipeline This repository is utilized for training and fine-tuning the **Sking Model** ([Hugging Face Model](https://huggingface.co/EntropyDrop/Sking)). Along with the dataset assets, it contains the complete automated pipeline for dual-layer 3D voxel rendering, multi-view layout baking, automatic skin format conversion (Alex to Steve), voxel edge texture consistency resolution, and a RESTful FastAPI service for extracting the actual usable 64x64 RGBA skin UV map from composite training targets. --- ## 🔗 Resources * **🗂️ Dataset**: [Hugging Face Sking Dataset](https://huggingface.co/datasets/EntropyDrop/Sking) * **🧠 Trained Model**: [Hugging Face Sking Model](https://huggingface.co/EntropyDrop/Sking) * **📝 Technical Report**: [Technical Architecture](https://entropydrop.com/skin/public/article/skingen) * **🌐 Online Demo**: [EntropyDrop Web Portal](https://entropydrop.com) --- ## 🚀 Key Features * **🎮 3D Voxel Rendering (`mc_render.py`)** - Powered by `PyVista` (VTK) to translate 2D skin textures into 3D voxel character meshes. - Supports dual-layer rendering: Core layer (base body) and Decor layer (jacket, sleeves, pants, hat). - Fully parameterizable limb articulation supporting rotation (Pitch/Yaw/Roll) and spatial offset configurations. - Interactive lighting mode with real-time viewport keyboard controls (W/S/A/D/Q/E for light position, R/F for intensity). - Supports orthographic and perspective projections, wireframe overlays, custom backgrounds, and alpha-transparent exports. * **🧩 Voxel Texture Consistency Resolver (`mc_voxel_texture_resolver.py`)** - Solves the visual gap artifact caused by transparent adjacent faces in dual-layer skins during 3D voxelization. - Implements a 3D voxel projection mapping algorithm that automatically fills missing/transparent adjacent faces according to a priority sequence (`Front -> Back -> Top -> Bottom -> Left -> Right`) for 3D renders. * **🔄 Layout Standardization: Alex-to-Steve (`alice_to_steve.py`)** - Automatically detects slim-armed (Alex, 3px arm width) skin formats. - Applies a pixel-column projection and replication mapping to expand slim arms to standard (Steve, 4px arm width) format to standardize features across the dataset. * **📸 Multi-View Layout Baking (`build_target_img.py`)** - Upsamples 64x64 flat textures via box filtering and injects 2x2 white indicators on background regions to represent alpha transparency values as conditioning cues for generative models. - Bakes a composite layout image at `768x768` resolution featuring the 2D skin texture along with **17 distinct, pre-configured 3D render viewports** (incorporating walking, idle, back-view, close-ups, and layer-toggled angles). * **⚡ Batch Processing Pipeline (`build_target_imgs.py`)** - Leverages a multi-threaded execution pool (`ThreadPoolExecutor`) managing isolated sub-processes for batch rendering. - Supports parallel processing on multi-core systems. * **🔓 Skin UV Map Extraction (`extract_skin.py`)** - **Extraction Engine**: Crops and extracts the actual usable 64x64 skin UV map from the 2D layout area of synthesized training target images, resolving alpha transparency indicators to recover clean texture maps. - **FastAPI Microservice**: Exposes the UV map extractor as a REST API alongside its command-line execution mode. * **📐 Conditioning Image Formatting (`force_resize_control_imgs.py`)** - Automatically resamples and centers control images inside a standard `1024x1024` alpha-transparent canvas utilizing Lanczos interpolation, ensuring compatibility with advanced ControlNet training frameworks. * **🔄 Skin UV & View Port Horizontal Flipping (`ext_flip_img.py`)** - Performs horizontal flipping of character front/back views in control images and correctly flips the corresponding 64x64 skin UV map. - Specifically handles 3D voxel box flipping (swapping left and right faces, horizontally flipping each face, and swapping left/right limbs/sleeves/pants/legs for Steve and Alex models). * **✂️ Front-View Dataset Slicing (`make_half_dataset.py`)** - Generates a front-view-only subset by horizontally splitting composite layout/control images in half, retaining only the left (front) side. - Automatically copies and standardizes associated files (PNG images, txt descriptions, and control maps) prefixing them with `half_`. * **🧬 Skin Merging Utility (`merge_skins.py`)** - Combines two skins by extracting the head and head decoration (decor) layers from Skin A and copying them onto the body and limbs of Skin B. - Utilizes head mapping coordinates matching standard UV layouts. --- ## 📂 Project Structure ```bash Sking/ ├── mc_render.py # Core 3D engine (PyVista viewport & headless off-screen rendering) ├── mc_voxel_texture_resolver.py # Voxel texture patcher & visual difference analyzer ├── alice_to_steve.py # Alex-to-Steve (3px-to-4px arm width) mapping algorithm ├── build_target_img.py # Single-skin multi-view layout baker (generates 768x768 composite) ├── build_target_imgs.py # Concurrent batch rendering pipeline ├── extract_skin.py # Skin UV map extraction CLI & FastAPI server ├── force_resize_control_imgs.py # Control map resampling & canvas standardization (1024x1024) ├── ext_flip_img.py # Flip front/back views and horizontally mirror skin UV layouts ├── make_half_dataset.py # Create front-view subset by slicing images in half horizontally ├── merge_skins.py # Combine head of skin A with body/limbs of skin B ├── skin-mask.png # Pixel-level spatial mapping mask for Core layer ├── skin-decor-mask.png # Pixel-level spatial mapping mask for Decor layer ├── skins/ # Directory for raw input skins (.png) ├── target_imgs_v73/ # Output directory for baked multi-view layouts ├── control_imgs/ # Processing directory for conditioning control maps └── control_imgs_v2/ # Directory for multi-view layout control maps ``` --- ## 🛠️ System Requirements & Installation ### 1. Prerequisites - Python 3.8 or higher. - A virtual environment configuration is highly recommended. ### 2. Installation Install all required packages: ```bash pip install pyvista numpy pillow fastapi uvicorn opencv-python pydantic ``` > **Note for Headless Environments**: Since `PyVista` utilizes VTK under the hood, running it on headless servers (e.g., Linux instances without GUI support) requires a virtual frame buffer configuration. Please wrap the execution using a utility like `xvfb-run`. --- ## 📖 Command Line & API Reference ### A. Bake Multi-View Layout for a Single Skin ```bash python build_target_img.py skins/steve.png target_imgs_v73/steve.png ``` This utility automatically executes the following pipeline sequence: 1. Validates texture dimension (64x64) and format integrity (RGBA). 2. Performs slim-arm check and converts Alex formats to Steve formats dynamically if needed. 3. Patches voxel edge-transparency conflicts. 4. Generates a `768x768` composite layout containing the 2D layout and 17 distinct 3D viewports. ### B. Batch Processing ```bash python build_target_imgs.py ``` Batch scans the `skins/` directory and processes them concurrently using parallel workers, exporting the output files into `target_imgs_v73/`. ### C. Interactive 3D Rendering & Viewing To examine or visually debug the 3D rendering configuration of a specific skin: ```bash python mc_render.py skins/my_skin.png --interact ``` - **Real-Time Light Position & Intensity Keyboard Controls**: - `W` / `S`: Translate light position along the Z-axis (Forward / Backward). - `A` / `D`: Translate light position along the X-axis (Left / Right). - `Q` / `E`: Translate light position along the Y-axis (Up / Down). - `R` / `F`: Increment / Decrement light intensity. - `P`: Print current light coordinate vector and intensity scalar to terminal output. - **Custom Articulation & Off-Screen Export Example**: ```bash python mc_render.py skins/my_skin.png --rot-head 15 30 0 --rot-arm-right -45 0 0 --save output.png ``` ### D. Skin UV Map Extraction API #### CLI Execution Mode ```bash python extract_skin.py --img target_imgs_v73/steve.png --output restored_steve.png ``` #### API Server Mode Run the FastAPI microservice: ```bash python extract_skin.py --server True ``` The microservice launches locally on `http://0.0.0.0:10010`. - **Endpoint**: `POST /extract` - **Request Body Format**: ```json { "img": "" } ``` - **Response Body Format**: ```json { "img": "" } ``` ### E. Horizontal Flipping of Views and UV Maps This script horizontally flips character front and back views separately for a ControlNet image, and mirrors the 64x64 skin UV map by swapping and mirroring corresponding limbs and details. ```bash python ext_flip_img.py ``` - Processes `control_imgs_v2/{original_id}.png` to generate flipped version at `control_imgs_v2/{new_id}.png`. - Flips `img_label/{original_id}.png` (UV map) to generate `img_label/{new_id}.png`. - Copies the corresponding text description from `img_label/{original_id}.txt` to `img_label/{new_id}.txt`. ### F. Front-View Dataset Slicing This script processes the dataset by horizontally cutting all layout/control images in half (keeping only the left half, which corresponds to the character's front view) to create a front-view-only training subset. ```bash python make_half_dataset.py ``` - Automatically processes files in `img_label/` and `control_imgs_v2/`. - Saves sliced files with the prefix `half_` (e.g. `half_{original_name}.png`, `half_{original_name}.txt`). - Proactively skips already processed files. ### G. Skin Merging Utility (Head of A + Body/Limbs of B) This script merges two skins by taking the head and hat decoration layers from Skin A and the body and limbs from Skin B. ```bash python merge_skins.py -o ``` - Extracts head region UVs (including outer decors) from skin A. - Pastes them over skin B's head region, outputting the newly combined skin. --- ## 📄 License This project is licensed under the GNU Affero General Public License v3.0 - see the [LICENSE](LICENSE) file for details.