# Spatial Interfaces

> Coordinate systems, anchors, tracking, depth, occlusion, hand/eye input, world understanding, and spatial UI.

Canonical: https://learn.significanthobbies.com/curriculum/concepts/spatial-interfaces

Coordinate systems, anchors, tracking, depth, occlusion, hand/eye input, world understanding, and spatial UI.

- Difficulty: core
- Tracks: Multimodal & Spatial Computing

## Mental model

Spatial interfaces place persistent state in a changing coordinate system. Tracking confidence, scale, depth, occlusion, ergonomics, and recovery from lost anchors are core.



## Primary sources

- [WebXR Device API](https://www.w3.org/TR/webxr/) (doc)

## Practice

### Design exercise: Spatial Interfaces

Coordinate systems, anchors, tracking, depth, occlusion, hand/eye input, world understanding, and spatial UI. Implement designOutline() returning non-empty values for: coordinateSystem, tracking, spatialInteraction. Each value must name a concrete mechanism or decision.

**Expected evidence:** A design outline with coordinateSystem, tracking, spatialInteraction plus an explicit failure mode or trade-off.

## Review prompts

- An anchor drifts, so placed content slowly slides off the real surface. What causes it and what does the UI owe the user?

## Build evidence

- **Synthesize: Multimodal & Spatial Computing** — Connect vision, audio, generation, on-device intelligence, robotics, spatial interfaces, and HCI. Produce one working system, benchmark, or evidence-backed design that integrates the path.

## Prerequisites

- [Human-Computer Interaction](https://learn.significanthobbies.com/curriculum/concepts/human-computer-interaction)
- [Pose & Motion Tracking](https://learn.significanthobbies.com/curriculum/concepts/pose-motion-tracking)

## Related concepts

- [Robotics Systems](https://learn.significanthobbies.com/curriculum/concepts/robotics-systems)
- [Human-Computer Interaction](https://learn.significanthobbies.com/curriculum/concepts/human-computer-interaction)

## Learning paths

- [12-Week Multimodal & Spatial Computing](https://learn.significanthobbies.com/curriculum/roadmaps/multimodal-spatial-12w)