# Grasping Linear Feature

> Fit the full 3D axis of an elongated segmented feature and grasp it with a perpendicular, inclination-aware parallel-jaw pose. Use for handles, rods, shafts, tools, utensils, and other linear parts whose pitch or roll matters; use grasping-short-axis instead when an upright OBB and vertical approach are sufficient.

- Skill: `graph-robots/grasping-linear-feature` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add graph-robots/grasping-linear-feature`
- Raw SKILL.md: https://api.skillmd.com/api/skills/graph-robots/grasping-linear-feature/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: Apache-2.0
- Author: graph-robots (https://skillmd.com/u/graph-robots)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/graph-robots/grasping-linear-feature

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# Grasping a full-3D linear feature

Use this skill when a segmented graspable part may be inclined in 3D. The
point cloud is reduced to a robust principal axis by
`geometry.fit_linear_feature`. The canonical script then builds a gripper
frame with its local Y axis along the feature and its local Z approach axis
perpendicular to it. The approach is chosen as close to world-down as the
perpendicular constraint permits.

Recommended flow:

```text
open → fit_axis → compute_grasp → pregrasp → descend → observe → close → grasped
```

`surface_inset` moves the fingertip target from the feature center along the
approach direction; `standoff` places the pregrasp back along the same line.
Keep both configurable because gripper geometry and point-cloud completeness
vary across platforms.

This skill generates and executes a grasp pose; it does not decide which
semantic part to grasp or verify object identity. Upstream perception should
provide a point cloud containing only the selected linear feature.