Update ground_truth/README.md

ground_truth/README.md

@@ -0,0 +1,114 @@
+# Ground Truth Annotations
+
+This directory contains the **full ground-truth annotations** used to construct the
+binary navigability labels (`answer`) in the main CapNav benchmark.
+
+While the primary benchmark file  
+`capnav_v0_with_answer.parquet`  
+provides **binary (True/False) navigability answers** for each
+(question, scene, agent) triple, the files in this directory expose the
+**underlying structural and traversability annotations** from which those
+binary labels are derived.
+
+These annotations offer **richer, fine-grained information** about scene
+structure, feasible routes, and failure cases, and are intended for
+researchers who wish to inspect, verify, or extend the benchmark.
+
+---
+
+## Directory Structure
+
+```
+ground_truth/
+├── graphs/
+│ └── <scene_id>-graph.json
+├── traverse/
+│ └── <scene_id>-traverse.json
+└── README.md
+```
+
+
+### `graphs/`
+
+This folder contains **scene-level spatial graph annotations** for each 3D environment.
+
+Each file corresponds to a single scene and encodes:
+- A graph representation of the indoor environment
+- Nodes representing semantically meaningful locations or regions
+- Edges representing potential transitions between nodes
+- Human-annotated connectivity reflecting the true physical layout of the scene
+
+These graphs serve as the **structural backbone** for all navigability and
+traversability reasoning in CapNav.
+
+---
+
+### `traverse/`
+
+This folder contains **route-level traversability annotations** built on top of the scene graphs.
+
+For each scene, the traverse annotations specify:
+- Whether a route between two nodes is traversable for a given agent
+- Agent-specific constraints (e.g., body size, ability to climb stairs)
+- Valid and invalid edges along candidate paths
+- Detailed reasons explaining *why* traversal is not possible when a route fails
+
+These files provide **richer supervision** than the binary labels alone,
+including intermediate decisions and failure rationales.
+
+---
+
+## Relationship to the Main Benchmark
+
+The main benchmark file:
+```
+capnav_v0_with_answer.parquet
+```
+
+contains a simplified representation of the ground truth:
+- Each row corresponds to a `(question, scene, agent)` triple
+- The `answer` column stores a **binary navigability label**
+- This binary label is **derived from the graph and traverse annotations**
+  in this directory
+
+In other words:
+
+> **The binary answers in the benchmark are a distilled view of the more
+> comprehensive ground-truth annotations provided here.**
+
+Researchers interested only in benchmarking model accuracy can rely on
+the parquet file directly, while those seeking deeper insight into
+navigation feasibility, path validity, or agent-specific constraints
+should consult the annotations in `ground_truth/`.
+
+---
+
+## Annotation Process
+
+All graph and traversability annotations in this directory are:
+- **Manually constructed** based on the true geometry and semantics of each scene
+- Verified to reflect realistic physical constraints and navigational affordances
+- Used as the authoritative source of ground truth in CapNav
+
+Details of the annotation pipeline, including tooling, validation logic,
+and quality control procedures, are documented in the CapNav repository:
+```
+https://github.com/Ruiqi-Chen-0216/CapNav
+```
+
+Please refer specifically to the **annotation code and documentation**
+in the repository for implementation details.
+
+---
+
+## Intended Use
+
+This directory is provided to support:
+- Transparency and reproducibility of the benchmark
+- Analysis of failure cases beyond binary correctness
+- Future extensions of CapNav (e.g., multi-step supervision, path prediction)
+- Research on agent-specific navigation constraints and embodied reasoning
+
+For most benchmarking use cases, users only need the main parquet file.
+The contents of `ground_truth/` are optional but recommended for advanced analysis.
+