Lab Session 2

 Achievements

The second week lab session was progressively a milestone for our team as it created and tested a script that tracks images and displays corresponding 3D Models in real time. This functionality is user-centred , allowing the user to scan the letters to dynamically render visual models.

Theoretical Concepts

Our design approach integrates AR Foundation's image tracking capabilities with Unity's prefab management system.
Key principles include:

1. Image Recognition in AR
   Using AR Foundation’s ARTrackedImageManager, the script identifies reference images (letters) in the surrounding and triggers the function which retrieves their tracking state.
2. Dynamic Content Placement
   3D Models are placed in corresponding to the letter which are then displayed in real time.
3. Interaction Design
   To make it more user interactive , joystick was added to play around with 3D Models.

Implementations

The week’s focus was on developing and refining the following components:

1. Image Tracking Script
   Implemented a C# script using Unity's AR Foundation to manage the recognition and tracking of letters.

   • Prefab Instantiation: 3D Models for each letter’s object (e.g., A for Apple, B for Bee) were instantiated at runtime and stored for management.
   • Dynamic Activation and Positioning: 3D Models were dynamically activated and positioned relative to the tracked image, ensuring accurate alignment.
   • Handling Tracking States: The script manages 3D Models visibility based on the tracking state of the associated letter image,  and also removes the model when the letter disappears.

2. Special Behaviour for Prefabs
   The Team introduced a interactive element for the 3D Models , where its rigidbody body component is activated to stimulate movement. This added extra element enusred excitement for children interacting with the app.

3. Prefab Offset
   Usage of prefabOffset ensured that the 3D Models do not overlap with their referenced images , which will provide clarity .

Challenges and Learning

Week 2 presented significant technical challenges:

• Managing Tracking States: Ensuring prefabs appeared and disappeared correctly based on the tracking state was crucial for usability.
• Physics Integration: Adding realistic behaviour to 3D Models.