> For the complete documentation index, see [llms.txt](https://docs.hello-robot.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hello-robot.com/stretch4-ros2-repo/stretch_core/config.md).

# stretch\_core filter configuration

Shared YAML under this directory configures the dual-lidar pipeline, robot self-filter geometry, and Nav2 footprint publisher.

## Point filter order (single pass per lidar point)

In `dual_lidar_pipeline.cpp` each point is transformed to `base_footprint`, then:

1. **Region filter** — cheap height/range crop (`z_min`, `z_max`, `range_max` from `dual_lidar_filter.yaml`).
2. **Self-filter spatial gate** — cheap XY cylinder (+ optional Z band) from `robot_self_filter.yaml`.
3. **Robot self-filter geometry** — expensive TF-driven volumes (base, arm, shoulder, wrist, attachment) only for points inside the gate.

Far points skip step 3 and remain as obstacles. Region and gate are different jobs: region shapes the scan; gate limits where robot geometry runs.

## Spatial gate vs other radii

| Parameter                   | Default | Shape          | Purpose                                                   |
| --------------------------- | ------- | -------------- | --------------------------------------------------------- |
| `self_filter_gate_radius_m` | 1.5 m   | Cylinder in XY | Near-field ROI for robot geometry checks                  |
| `base_radius`               | 0.25 m  | Cylinder in XY | Actual base robot volume removed as self-hit              |
| `dist_rob`                  | 2.5 m   | Square in XY   | VoxelSor denoise ROI when `filter_type:=sor` (navigation) |

Tune `self_filter_gate_radius_m` to at least max arm+tool XY reach (\~1.0–1.2 m). Increase (e.g. 1.7 m) if extended-arm returns leak into `/scan_filtered`.

Gate parameters in `robot_self_filter.yaml`:

* `self_filter_spatial_gate_enabled` — master switch
* `self_filter_gate_radius_m` — XY circle radius
* `self_filter_gate_z_min_m` / `self_filter_gate_z_max_m` — optional height band inside the cylinder

## RViz self-filter markers

Enable with `pub_self_filter_markers: true` (on by default in `self_filter_debug.launch.py`). Topic: `/self_filter_markers`.

| Namespace                  | Meaning                                                                                              |
| -------------------------- | ---------------------------------------------------------------------------------------------------- |
| `self_filter/gate`         | Spatial gate volume (near-field ROI)                                                                 |
| `self_filter/gate_ring`    | Ground circle at gate radius (easy top-down read)                                                    |
| `self_filter/base`         | Base filter geometry (`base_radius`)                                                                 |
| `self_filter/arm`          | Arm capsule                                                                                          |
| `self_filter/arm_shoulder` | Shoulder OBB                                                                                         |
| `self_filter/wrist/<link>` | Wrist chain OBBs (index order in `wrist_chain_frames`)                                               |
| `self_filter/attachment`   | Tool attachment OBB (anchored at `quick_connect_interface_link`; tune via `attachment_box_origin_*`) |

Launch debug view:

```bash
ros2 launch stretch_core self_filter_debug.launch.py tool_preset:=sg4 use_rviz:=true
```

The parameters can be update, and example to resize the live gate:

```bash
ros2 param set /pointcloud_to_laserscan self_filter_gate_radius_m 1.7
```

Note: I noticed it only takes effect after running another command with ros2 param set, so if you dont see chnages run the same command twice.

You can use `ros2 param list /pointcloud_to_laserscan` to check the parameters that can be updated.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.hello-robot.com/stretch4-ros2-repo/stretch_core/config.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.