# AGENTS.md This file provides guidance to AI coding assistants when working with code in this repository. ## What this is A dora-rs C++ node that interfaces with ZED stereo cameras. On each tick it grabs a frame, runs object detection, and publishes four outputs over the dora dataflow: a BGR image, an XYZRGBA point cloud, camera intrinsics, and detected objects with 3D positions. Camera management lives in `src/zed/`, detection engines in `src/engines/`, and the dora event loop in `src/main.cc`. ## Build ```bash mkdir -p build && cd build && cmake .. && make install ``` The binary is installed to `bin/dora_zed` relative to the repo root. **Requirements:** CMake 3.21+, ZED SDK 5.x (at `/usr/local/zed`), CUDA Toolkit, ONNX Runtime 1.20+ (system install), Rust stable toolchain (for dora-rs C++ bindings). The first build clones dora-rs from GitHub and compiles `dora-node-api-cxx` via Cargo. This takes a while. Subsequent builds are incremental. If `DORA_ROOT_DIR` is set to a local dora checkout, it builds against that instead. For a build without installing the SDK stack on the host, see the `Dockerfile` (Ubuntu 24.04 — the newest release with a ZED SDK; there is no Stereolabs build for 26.04). Run the compile with `--gpus all`. ## Run ```bash dora up dora start dataflow.yml ``` Camera and detection behavior is configured entirely through environment variables (see README.md for the full list: `ZED_RESOLUTION`, `ZED_FPS`, `ZED_DEPTH_MODE`, `ZED_DETECTION_MODEL`, etc.). ## Architecture - **`src/util/env.h`** — Shared inline env-variable parsing helpers (`get_env_int`, `get_env_str`, `get_env_bool`, `get_env_float`). - **`src/zed/camera.h`** — `zed::Config`, `zed::Calibration`, and `zed::Camera` class. Camera wraps the ZED SDK lifecycle: open (with retry loop), warmup, grab (image + point cloud), calibration, and close. Exposes `handle()` for engine access. - **`src/zed/camera.cc`** — Implementation. SDK enum parsers live in an anonymous namespace. - **`src/engines/engine.h`** — `engines::DetectedObject` struct and `engines::Engine` abstract base class (`enable`, `detect`, `objects`, `label_names`). - **`src/engines/zed_native.h/cc`** — `engines::ZedNative`: wraps ZED SDK's TensorRT-optimized object detection module. - **`src/engines/yolo_helpers.h`** — Header-only shared helpers used by the ONNX engine: `RawDetection`, `nms()`, `letterbox()`, `fuse_bbox()`, `backproject()`. Lives in `engines::detail` namespace. - **`src/engines/yolo_onnx.h/cc`** — `engines::YoloOnnx` / `YoloOnnxConfig`: closed-vocabulary detection for any single-input YOLO ONNX model (YOLOv8, YOLOv11, YOLOv5, etc.). Auto-detects output layout (`NC_FIRST` / `NC_LAST` / `NC_LAST_OBJ`) from tensor shape; override with `ZED_ONNX_OUTPUT_FORMAT`. Labels loaded from `ZED_ONNX_LABELS` or `ZED_ONNX_LABELS_FILE`. - **`src/main.cc`** — Dora event loop. Selects engine via `ZED_ENGINE` env var (`yolo_onnx`/`onnx` or `native`), holds a `std::unique_ptr`. Parses `ZED_PC_MODE` (`FULL`/`HALF`/`ROI`) once before the loop. On any input event (intended to be driven by a tick timer; the id is not inspected): calls `camera.grab()` and `detector->detect()`, then sends `image_bgr`, `point_cloud`, `camera_info`, and `objects` outputs. Point cloud output varies by mode: `FULL` sends the raw `sl::Mat` pointer (no copy); `HALF` downsamples by 2 in each dimension; `ROI` emits only valid points within detected bounding boxes as a flat `[N, 4]` array. Handles reconnection on grab failure. - **`DoraTargets.cmake`** — Handles building or fetching dora-rs and generating the CXX bridge files. Two paths: local (`DORA_ROOT_DIR`) or git clone. Produces `dora_node_api_cxx` library and the `node_bridge.cc` glue. - **`dataflow.yml`** — Example dora dataflow definition using the `git:` source format. - **`Dockerfile`** — Ubuntu 24.04 x86-64 build environment (CUDA 12.8, ZED SDK 5.2, ONNX Runtime, Rust). No ARM64/Jetson image; build natively there. No camera needed; run the compile with `--gpus all`. Sets `NVIDIA_DRIVER_CAPABILITIES=compute,utility,video` — the `video` capability is what makes the container runtime mount NVDEC/NVENC, which `libsl_zed.so` links against. ONNX Runtime's CMake package files are relocated to `/usr/local/lib/cmake` because Ubuntu's multiarch CMake does not search `lib64`. Rust lives at `/usr/local/{rustup,cargo}` rather than `/root` so the build can run as the invoking user. `docker build -t dora-zed-build . && docker run --rm --gpus all --user "$(id -u):$(id -g)" -v "$PWD:/src" -v dora-zed-cargo:/usr/local/cargo/registry dora-zed-build`. - **`scripts/export_yolo.py`** — PEP 723 uv script. Exports a standard YOLOv11 model to ONNX for closed-vocabulary detection. Run: `uv run scripts/export_yolo.py --model n --output-dir models/`. - **`src/test_yolo_onnx.cc`** — Standalone C++ test binary (`bin/test_yolo_onnx`). Exercises `YoloOnnx` with an image (default `test/assets/yolo.png`). No dora and no live camera required. Uses the same env vars as the main binary. Saves an annotated result image alongside the input. ## Key APIs - **dora C++ API** (``): `init_dora_node()`, `dora_node.events->next()`, `event_type()`, `send_output_with_metadata()`, `new_metadata()`. - **ZED SDK** (``): `sl::Camera`, `sl::InitParameters`, `sl::RuntimeParameters`, `sl::Mat`, `sl::ObjectDetectionParameters`, `sl::Objects`. - **ONNX Runtime** (``): `Ort::Env`, `Ort::Session`, `Ort::SessionOptions`, `Ort::Value`. Used by the `yolo_onnx` engine. - Output data is sent as raw byte slices (`rust::Slice`) with typed metadata (shape, dtype, encoding). ## Tools - **Issue tracker:** Gitea. Use the Gitea MCP tools (`mcp__gitea__*`) to read and manage issues, pull requests, and other repository operations. ## Rules - Do not mention AI tools in commit messages or documentation.