# LiDAR

Light Detection and Ranging (LiDAR) is a technique that uses lasers to measure distance to an object.

# What is Lidar scanning?

**LiDAR** stands for *Light Detection and Ranging*.

- It works by shooting out tiny pulses of infrared light (lasers).
- Each pulse bounces back when it hits a surface.
- The device measures the time it takes to return → this gives the **distance** to that surface.
- Millions of these measurements build up a **point cloud** = a digital 3D map of the environment or object.

**LiDAR captures the shape of real objects in 3D, with depth and scale**, not just flat photos.

Artists use LiDAR scanning to:

- Capture **sculptures, costumes, installations, or landscapes** as precise 3D models.
- Create **digital doubles** of their work for archiving or documentation.
- Remix physical works in **VR/AR, projection mapping,** or dataflow software like **TouchDesigner**.
- Use scans as a **starting point for fabrication** (3D printing, CNC, etc.).

It’s not about photorealistic color but about **geometry**—a solid spatial “skeleton” you can texture, render, or transform artistically.

# Depth camera's on Apple iPad and iPhone Pro models

Apple uses both **depth cameras** and **LiDAR** in different products, and while they sound similar (both measure distance), they work in different ways and are suited for different use cases.  
**TrueDepth** = short range, detailed face/hand depth → Face ID & AR effects.  
**LiDAR** = room-scale, larger depth sensing → AR, scanning, 3D modeling.

You can think of it like this:

- Depth camera = microscope for your face 👤
- LiDAR = flashlight that measures the whole room 🌌

<table border="1" id="bkmrk-depth-camera-%28truede" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr><td>## Depth Camera   
(TrueDepth system – e.g. Face ID on iPhone/iPad)

- **How it works:**
    
    
    - Uses **infrared (IR) structured light**.
    - The projector shines ~30,000 tiny IR dots on your face.
    - An IR camera captures how those dots are distorted by the 3D shape of your face.
    - Software reconstructs a **depth map**.
- **Range:** Short — typically **0.3 to ~1 meter**, optimized for faces and selfies.
- **Use cases on Apple devices:**
    
    
    - **Face ID** (unlocking and Apple Pay).
    - **Animoji / Memoji** face tracking.
    - Portrait selfies with depth.
    - AR effects at arm’s length.
- **Strengths:**
    
    
    - Very accurate at close range.
    - Compact — fits in the notch of iPhones/iPads.
    - Works in total darkness (IR).
- **Limitations:**
    
    
    - Not designed for room-scale scanning.
    - Limited depth resolution past ~1m.

</td><td>## LiDAR Scanner   
(on iPad Pro, iPhone Pro models since 2020)

- **How it works:**
    
    
    - Uses **time-of-flight LiDAR**.
    - Shoots pulses of infrared laser light.
    - Measures how long they take to return → direct **distance measurement**.
- **Range:** Much longer — **up to ~5 meters indoors**.
- **Use cases on Apple devices:**
    
    
    - Room and object scanning.
    - AR apps that need instant, accurate scene mapping.
    - Faster autofocus in low light (because it knows the distance to objects).
    - 3D scanning (e.g., for art, furniture, architecture).
- **Strengths:**
    
    
    - Works at room scale.
    - Very fast: instant AR scene setup.
    - Great for **3D modeling &amp; scanning**.
- **Limitations:**
    
    
    - Lower resolution than cameras (you don’t get a detailed point cloud like pro LiDAR sensors).
    - Still consumer-grade, not survey-grade accuracy.

</td></tr></tbody></table>

Here's a nice blog on how to use Apple Lidar &amp; integrate with **Touchdesigner**:  
[https://interactiveimmersive.io/blog/touchdesigner-3d/3d-scanning-with-apples-lidar/](https://interactiveimmersive.io/blog/touchdesigner-3d/3d-scanning-with-apples-lidar/)