| --- |
| license: mit |
| license_link: LICENSE |
| extra_gated_eu_disallowed: true |
| pipeline_tag: image-to-3d |
| --- |
| |
|
|
| <div align="center"> |
|
|
| # Pixal3D: Pixel-Aligned 3D Generation from Images |
|
|
| <h3>SIGGRAPH 2026</h3> |
|
|
| <small>[Dong-Yang Li](https://ldyang694.github.io/)¹ · [Wang Zhao](https://thuzhaowang.github.io/)²* · [Yuxin Chen](https://orcid.org/0000-0002-7854-1072)² · [Wenbo Hu](https://wbhu.github.io/)² · [Meng-Hao Guo](https://menghaoguo.github.io/)¹ · [Fang-Lue Zhang](https://fanglue.github.io/)³ · [Ying Shan](https://www.linkedin.com/in/YingShanProfile)² · [Shi-Min Hu](https://cg.cs.tsinghua.edu.cn/shimin.htm)¹✉</small> |
|
|
| ¹Tsinghua University (BNRist) ²Tencent ARC Lab ³Victoria University of Wellington |
|
|
| *Project lead ✉Corresponding author |
| |
| </div> |
| |
| <div align="center"> |
| <a href="https://ldyang694.github.io/projects/pixal3d/"><img src=https://img.shields.io/badge/Project%20Page-333399.svg?logo=googlehome height=22px></a> |
| <a href="https://github.com/TencentARC/Pixal3D"><img src=https://img.shields.io/badge/GitHub-181717.svg?logo=github&logoColor=white height=22px></a> |
| <a href="https://huggingface.co/spaces/TencentARC/Pixal3D"><img src=https://img.shields.io/badge/%F0%9F%A4%97%20Demo-276cb4.svg height=22px></a> |
| <a href="https://huggingface.co/TencentARC/Pixal3D"><img src=https://img.shields.io/badge/%F0%9F%A4%97%20Models-d96902.svg height=22px></a> |
| <a href="https://arxiv.org/abs/2605.10922"><img src=https://img.shields.io/badge/Arxiv-b5212f.svg?logo=arxiv height=22px></a> |
| <a href="LICENSE"><img src=https://img.shields.io/badge/License-MIT-yellow.svg height=22px></a> |
| </div> |
| |
| |
| **Pixal3D** generates high-fidelity 3D assets from a single image. Unlike previous methods that loosely inject image features via attention, Pixal3D explicitly lifts pixel features into 3D through back-projection, establishing direct pixel-to-3D correspondences. This enables near-reconstruction-level fidelity with detailed geometry and PBR textures. |
| |
| --- |
| |
| ## ✨ News |
| |
| - **May 2026**: Release training code and data preparation toolkit. 🔧 |
| - **May 2026**: Release the improved version based on [Trellis.2](https://github.com/microsoft/TRELLIS.2) backbone. 💪 |
| - **May 2026**: Release inference code and online demo. 🤗 |
| - **Apr 2026**: Our paper is accepted to SIGGRAPH 2026! 🎉 |
| |
| ## 📌 Branches |
| |
| | Branch | Description | |
| |--------|-------------| |
| | `main` | **Latest version** — improved implementation based on [Trellis.2](https://github.com/microsoft/TRELLIS.2) backbone with better performance. | |
| | `paper` | **Paper version** — original implementation based on [Direct3D-S2](https://github.com/DreamTechAI/Direct3D-S2), corresponding to results reported in our SIGGRAPH 2026 paper. | |
| |
| > If you want to reproduce the results in our paper, please switch to the `paper` branch. |
| |
| ## 🎮 Try It Online |
| |
| You can try Pixal3D directly in your browser without any installation via our Hugging Face Gradio demo: |
| |
| 👉 [**Launch Demo**](https://huggingface.co/spaces/TencentARC/Pixal3D) |
| |
| ## 🚀 Getting Started |
| |
| ### Installation |
| |
| #### Step 1: Follow TRELLIS.2 Installation |
| |
| Please first follow the installation guide of [TRELLIS.2](https://github.com/microsoft/TRELLIS.2) to set up the base environment. |
| |
| #### Step 2: Install Additional Dependencies |
| |
| ```bash |
| pip install -r requirements.txt |
| ``` |
| |
| #### Step 3: Install natten |
| |
| ```bash |
| NATTEN_CUDA_ARCH="xx" NATTEN_N_WORKERS=xx pip install natten==0.21.0 --no-build-isolation |
| ``` |
| |
| Please replace `xx` with the CUDA architecture and the number of build workers suitable for your machine. |
| |
| #### Step 4: Install utils3d |
| |
| ```bash |
| pip install https://github.com/LDYang694/Storages/releases/download/20260430/utils3d-0.0.2-py3-none-any.whl |
| ``` |
| |
| > **Note**: `requirements-hfdemo.txt` is for the Hugging Face Spaces demo (H-series GPU architecture) and may not be compatible with other architectures. |
| |
| ### Usage |
| |
| #### Inference |
| |
| Generate a GLB mesh from a single image: |
| |
| ```bash |
| python inference.py --image assets/images/0_img.png --output ./output.glb |
| ``` |
| |
| **Low-VRAM mode** (reduces peak VRAM by loading models on-demand): |
| |
| ```bash |
| python inference.py --image assets/images/0_img.png --output ./output.glb --low_vram |
| ``` |
| |
| By default, the pipeline resolution is **1536** (standard mode) or **1024** (low-VRAM mode). You can override this with `--resolution`: |
| |
| ```bash |
| # Force 1536 even in low-VRAM mode |
| python inference.py --image assets/images/0_img.png --output ./output.glb --low_vram --resolution 1536 |
| |
| # Force 1024 in standard mode |
| python inference.py --image assets/images/0_img.png --output ./output.glb --resolution 1024 |
| ``` |
| |
| **Tip**: If you don't have `flash_attn` installed, you can use PyTorch's built-in SDPA backend instead: |
| > ```bash |
| > ATTN_BACKEND=sdpa python inference.py --image assets/images/0_img.png --output ./output.glb --low_vram |
| > ``` |
| |
| ### Web Demo |
| |
| We provide a Gradio web demo for Pixal3D, which allows you to generate 3D meshes from images interactively. |
| |
| ```bash |
| python app.py |
| ``` |
| |
| Low-VRAM mode is also available for the web demo. The frontend default resolution will automatically switch to 1024 in low-VRAM mode (1536 otherwise), but can be changed manually in the UI. |
| |
| ```bash |
| python app.py --low_vram |
| # or via environment variable: |
| LOW_VRAM=1 python app.py |
| ``` |
| ## 🔧 Training |
| |
| We provide the full training codebase for reproducing Pixal3D from scratch. |
| |
| ### Data Preparation |
| |
| Prepare view-aligned O-Voxel data and rendered condition images by following the data toolkit instructions: |
| |
| > 📂 **[data_toolkit/README.md](data_toolkit/README.md)** |
| |
| ### Overview |
| |
| Pixal3D is trained as a three-stage cascade, each progressively increasing resolution: |
| |
| | Stage | Model | Resolutions | Config Prefix | |
| |-------|-------|-------------|---------------| |
| | 1 | Sparse Structure | 32 → 64 | `ss_flow_img_dit_*_proj_finetune` | |
| | 2 | Shape | 256 → 512 → 1024 | `slat_flow_img2shape_*_proj_finetune` | |
| | 3 | Texture | 256 → 512 → 1024 | `slat_flow_imgshape2tex_*_proj_finetune` | |
|
|
| All stages use **pixel-aligned projection conditioning** and **view-aligned latents** (2 views by default). Within each stage, start from the lowest resolution and progressively fine-tune to higher resolutions by setting `finetune_ckpt` in the config. |
|
|
| ### Quick Start |
|
|
| ```sh |
| python train.py \ |
| --config <CONFIG_JSON> \ |
| --output_dir <OUTPUT_DIR> \ |
| --data_dir '<DATA_DIR_JSON>' |
| ``` |
|
|
| `--data_dir` is a JSON string describing the dataset layout. Different stages require different keys: |
|
|
| | Stage | Required keys | |
| |-------|---------------| |
| | Sparse Structure | `base`, `ss_latent`, `render_cond` | |
| | Shape | `base`, `shape_latent`, `render_cond` | |
| | Texture | `base`, `shape_latent`, `pbr_latent`, `render_cond` | |
|
|
| ### Example: Training All Three Stages |
|
|
| Below we show the full training sequence using ObjaverseXL as an example. Each higher-resolution step requires updating `finetune_ckpt` in its config JSON to point to the previous checkpoint. |
|
|
| <details> |
| <summary><b>Stage 1: Sparse Structure (32 → 64)</b></summary> |
|
|
| ```sh |
| # Resolution 32 |
| python train.py \ |
| --config configs/gen/ss_flow_img_dit_1_3B_32_bf16_proj_finetune.json \ |
| --output_dir results/ss_32 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "ss_latent": "datasets/ObjaverseXL_sketchfab/ss_latents/ss_enc_conv3d_16l8_fp16_64_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| |
| # Resolution 64 (set finetune_ckpt → results/ss_32 checkpoint) |
| python train.py \ |
| --config configs/gen/ss_flow_img_dit_1_3B_32_bf16_proj_finetune_ft64.json \ |
| --output_dir results/ss_ft64 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "ss_latent": "datasets/ObjaverseXL_sketchfab/ss_latents/ss_enc_conv3d_16l8_fp16_64_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| ``` |
| </details> |
|
|
| <details> |
| <summary><b>Stage 2: Shape (256 → 512 → 1024)</b></summary> |
|
|
| ```sh |
| # Resolution 256 |
| python train.py \ |
| --config configs/gen/slat_flow_img2shape_dit_1_3B_256_bf16_proj_finetune.json \ |
| --output_dir results/shape_256 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "shape_latent": "datasets/ObjaverseXL_sketchfab/shape_latents/shape_enc_next_dc_f16c32_fp16_256_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| |
| # Resolution 512 |
| python train.py \ |
| --config configs/gen/slat_flow_img2shape_dit_1_3B_256_bf16_proj_finetune_ft512.json \ |
| --output_dir results/shape_ft512 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "shape_latent": "datasets/ObjaverseXL_sketchfab/shape_latents/shape_enc_next_dc_f16c32_fp16_512_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| |
| # Resolution 1024 |
| python train.py \ |
| --config configs/gen/slat_flow_img2shape_dit_1_3B_512_bf16_proj_finetune_ft1024.json \ |
| --output_dir results/shape_ft1024 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "shape_latent": "datasets/ObjaverseXL_sketchfab/shape_latents/shape_enc_next_dc_f16c32_fp16_1024_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| ``` |
| </details> |
|
|
| <details> |
| <summary><b>Stage 3: Texture (256 → 512 → 1024)</b></summary> |
|
|
| ```sh |
| # Resolution 256 |
| python train.py \ |
| --config configs/gen/slat_flow_imgshape2tex_dit_1_3B_256_bf16_proj_finetune.json \ |
| --output_dir results/tex_256 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "shape_latent": "datasets/ObjaverseXL_sketchfab/shape_latents/shape_enc_next_dc_f16c32_fp16_256_view", "pbr_latent": "datasets/ObjaverseXL_sketchfab/pbr_latents/tex_enc_next_dc_f16c32_fp16_256_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| |
| # Resolution 512 |
| python train.py \ |
| --config configs/gen/slat_flow_imgshape2tex_dit_1_3B_512_bf16_proj_finetune.json \ |
| --output_dir results/tex_512 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "shape_latent": "datasets/ObjaverseXL_sketchfab/shape_latents/shape_enc_next_dc_f16c32_fp16_512_view", "pbr_latent": "datasets/ObjaverseXL_sketchfab/pbr_latents/tex_enc_next_dc_f16c32_fp16_512_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| |
| # Resolution 1024 |
| python train.py \ |
| --config configs/gen/slat_flow_imgshape2tex_dit_1_3B_512_bf16_proj_finetune_ft1024.json \ |
| --output_dir results/tex_ft1024 \ |
| --data_dir '{"ObjaverseXL_sketchfab": {"base": "datasets/ObjaverseXL_sketchfab", "shape_latent": "datasets/ObjaverseXL_sketchfab/shape_latents/shape_enc_next_dc_f16c32_fp16_1024_view", "pbr_latent": "datasets/ObjaverseXL_sketchfab/pbr_latents/tex_enc_next_dc_f16c32_fp16_1024_view", "render_cond": "datasets/ObjaverseXL_sketchfab/renders_cond"}}' |
| ``` |
| </details> |
|
|
| ### Additional Options |
|
|
| <details> |
| <summary><b>All command-line arguments</b></summary> |
|
|
| | Argument | Description | Default | |
| |----------|-------------|---------| |
| | `--config` | Config JSON path | *required* | |
| | `--output_dir` | Output directory | *required* | |
| | `--data_dir` | Dataset JSON string | `./data/` | |
| | `--load_dir` | Checkpoint load directory | `output_dir` | |
| | `--ckpt` | Resume from step | `latest` | |
| | `--auto_retry` | Retries on failure | `3` | |
| | `--tryrun` | Dry run | `false` | |
| | `--profile` | Profiling | `false` | |
| | `--num_nodes` | Number of nodes | `1` | |
| | `--node_rank` | Current node rank | `0` | |
| | `--num_gpus` | GPUs per node | all | |
| | `--master_addr` | Master address | `localhost` | |
| | `--master_port` | Master port | `12666` | |
| | `--use_wandb` | Enable W&B logging | `false` | |
| | `--wandb_project` | W&B project | `trellis2-training` | |
| | `--wandb_name` | W&B run name | basename of `output_dir` | |
| | `--wandb_id` | W&B run ID (resume) | — | |
|
|
| </details> |
|
|
| ## 🌐 Community Projects |
|
|
| We thank the community for building extensions and deployment guides for Pixal3D! |
|
|
| - [Pixal3D-ComfyUI](https://github.com/Saganaki22/Pixal3D-ComfyUI) — ComfyUI integration with deployment guides for Windows, WSL, and more. |
|
|
| ## 🤗 Acknowledgements |
|
|
| This project is heavily built upon [Trellis.2](https://github.com/microsoft/TRELLIS.2) and [Direct3D-S2](https://github.com/DreamTechAI/Direct3D-S2). We sincerely thank the authors for their outstanding work on scalable 3D generation , which serves as the foundation of our codebase and model architecture. |
|
|
| We also thank the following repos for their great contributions: |
|
|
| - [Direct3D-S2](https://github.com/DreamTechAI/Direct3D-S2) |
| - [Trellis](https://github.com/microsoft/TRELLIS) |
| - [Trellis.2](https://github.com/microsoft/TRELLIS.2) |
|
|
| ## 📄 Citation |
|
|
| If you find this work useful, please consider citing: |
|
|
| ```bibtex |
| @article{li2026pixal3d, |
| title={Pixal3D: Pixel-Aligned 3D Generation from Images}, |
| author={Li, Dong-Yang and Zhao, Wang and Chen, Yuxin and Hu, Wenbo and Guo, Meng-Hao and Zhang, Fang-Lue and Shan, Ying and Hu, Shi-Min}, |
| journal={arXiv preprint arXiv:2605.10922}, |
| year={2026} |
| } |
| ``` |
|
|
| ## 📜 License |
|
|
| This project is released under the [MIT License](LICENSE). The third-party components included in this project remain licensed under their respective original terms; see [NOTICE](NOTICE) for the full list of dependencies and their licenses. |