Update Puffin-World camera documentation

README.md

@@ -4,6 +4,7 @@ task_categories:
 - image-to-3d
 - image-text-to-image
 - any-to-any
+arxiv: 2609.04196
 tags:
 - Camera
 - 3D Vision
@@ -21,7 +22,7 @@ tags:
 ![camera map collage](analysis/APTv2-Camera.png)
 
 Per-image camera parameter annotations for the **APTv2** dataset
-(an animal pose estimation & tracking benchmark; 41,569 images across 9 shards), captioned by the [**Puffin-World**](https://github.com/KangLiao929/Puffin) model. More captioned datasets are provided in our [**Puffin-16M**](https://kangliao929.github.io/projects/puffin-16m/) website.
+(an animal pose estimation & tracking benchmark; 41,569 images across 9 shards), captioned by the [**Puffin-World**](https://huggingface.co/ACERobotics/Puffin-World) model. More captioned datasets are provided in our [**Puffin-16M**](https://kangliao929.github.io/projects/puffin-16m/) website.
 
 The collage above visualizes the camera maps on sample images — each
 pair shows the **up field** (green arrows: the projected gravity-up direction)
@@ -73,12 +74,42 @@ You can download the entire dataset using the following command:
 hf download KangLiao/APTv2-Camera --repo-type dataset
 ```
 
+### From Camera Parameters to Up and Latitude Fields
+
+The released `(roll, pitch, vfov, k1)` annotations can be converted into the dense perspective-field representation used by Puffin-World. The conversion computes focal length from `vfov`, constructs a radial camera, and maps roll and pitch to the gravity direction. [`get_perspective_field`](https://github.com/KangLiao929/Puffin/blob/main/Puffin-World/scripts/camera/geometry/perspective_fields.py) then returns a normalized 2-channel **up field** and a 1-channel **latitude field**. The up field encodes the projected world-up direction at every pixel, while the latitude field measures each viewing ray's angular elevation relative to the horizon.
+
+```python
+import json
+import torch
+from scripts.camera.geometry.camera import SimpleRadial
+from scripts.camera.geometry.gravity import Gravity
+from scripts.camera.geometry.perspective_fields import get_perspective_field
+from scripts.camera.utils.conversions import fov2focal
+
+with open("camera.json") as f:
+    annotation = json.load(f)
+roll, pitch, vfov, k1 = (
+    annotation[key] for key in ("roll", "pitch", "vfov", "k1")
+)
+
+H, W = 512, 512
+f = float(fov2focal(torch.tensor(vfov), H))
+camera = SimpleRadial(torch.tensor(
+    [W, H, f, f, W / 2, H / 2, k1, 0.0]
+).float()).scale(torch.tensor([1.0, 1.0]))
+gravity = Gravity.from_rp(torch.tensor(roll), torch.tensor(pitch))
+up_field, latitude_field = get_perspective_field(camera, gravity)
+# Shapes: [1, 2, H, W] and [1, 1, H, W]
+```
+
+Run the example from the `Puffin-World` directory. Use [`plot_vector_fields` and `plot_latitudes`](https://github.com/KangLiao929/Puffin/blob/main/Puffin-World/scripts/camera/visualization/viz2d.py) to render up-field arrows and latitude heatmaps or contours. See [`save_pf_visualization`](https://github.com/KangLiao929/Puffin/blob/main/Puffin-World/scripts/demo/physics_perception.py) for an end-to-end visualization example.
+
 ### Caption Pipeline
-Beyond this captioned dataset, we also release **a complete captioning pipeline** for annotating camera parameters for arbitrary datasets, analyzing camera parameter distributions, and visualizing the corresponding camera maps. The pipeline is available in our [GitHub repository](https://github.com/KangLiao929/Puffin).
+Beyond this captioned dataset, we also release **a complete captioning pipeline** for annotating camera parameters for arbitrary datasets, analyzing camera parameter distributions, and visualizing the corresponding camera maps. The pipeline is available in our [GitHub repository](https://github.com/KangLiao929/Puffin/blob/main/Puffin-World/documents/ANNOTATION_CAMERA.md).
 
 
 ### Citation
-If you find the captioned dataset useful for your research or applications, please cite our paper using the following BibTeX:
+If you find the captioned dataset useful for your research or applications, please cite the following papers using these BibTeX entries:
 
 ```bibtex
   @article{liao2025puffin,
@@ -87,4 +118,12 @@ If you find the captioned dataset useful for your research or applications, plea
     journal={arXiv preprint arXiv:2510.08673},
     year={2025}
   }
+
+  @article{liao2026puffinworld,
+    title={Puffin-World: Scaling a Unified Multimodal Model with Native 3D World States},
+    author={Liao, Kang and Luo, Yihang and Wu, Xiao-Ming and Jin, Linyi and Wu, Size and Lin, Chunyu and Zhao, Yao and Wang, Fei and Li, Wei and Loy, Chen Change},
+    journal={arXiv preprint arXiv:2609.04196},
+    year={2026}
+  }
 ```
+