TargetLock

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  settings

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  history logs

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  custom height set

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  Init screen with camera view

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  Start measure the distance

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  predefined height sets

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  Run Screen

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  calculated distance to the object by it predefined user set height

Inspiration

We wanted a fast, offline way to estimate distance to people or animals using only a phone camera. Stadiametric rangefinding and ARKit intrinsics made it possible without LiDAR, and the Moon Home Agency initiative motivated a practical, field-ready solution.

What it does

TargetLock measures the distance to a person or object of known height. The user taps the top and bottom of the target, selects a height preset or custom value, and the app calculates distance using the pinhole camera model. It also provides diagnostics, measurement confidence, history, and optional zoom for better targeting.

How we built it

We built a Swift iOS app using ARKit, SceneKit, and UIKit. The app retrieves camera intrinsics, converts tap distance to pixels, and applies the distance formula. We added UI enhancements, haptics, settings, history with sharing, diagnostics, and a simple tutorial. The code is organized into small helpers (settings, presets, calculator, haptics).

Challenges we ran into

Getting accurate measurements from taps was tricky, especially across orientations and different devices. We also had to ensure the UI stayed responsive and avoid first-use lag. Adding zoom required careful correction so calculations stayed accurate.

Accomplishments that we're proud of

We delivered a fully offline, field-ready AR distance tool with a clean UI, presets, confidence scoring, diagnostics, and a history view. The app is lightweight, fast, and easy to use without network access.

What we learned

We learned how to use ARKit intrinsics for practical measurement, how UI/UX details (haptics, overlays, confidence, history) improve usability, and how to structure a Swift app for maintainability.

What's next for TargetLock

Planned improvements include accessibility support, optional onboarding flow, richer export formats (CSV/JSON/PDF), and further accuracy improvements such as object-angle guidance and calibration tools.

Built With

• swift