3D Wrist Tracking for Markerless AR Watch Try-On

Solution Overview

Problem

Existing online shopping experiences lack the ability for users to virtually try on physical items, such as wristwatches, without the need for physical indexing wristbands, which can be inconvenient and prone to errors.

Innovation Solution

A computing system captures video of a user's wrist, determines 3D parameters using image processing, and generates an augmented reality interface to overlay virtual items that match the orientation and rotation of the user's wrist in real-time, eliminating the need for physical indexing wristbands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If physical indexing wristbands are used to enable virtual try-on, then virtual try-on capability is achieved, but device complexity and ease of operation deteriorate due to required physical distribution and potential user error

Engineering Contradiction:

Improvevirtual try-on capabilityVSAvoidphysical distribution requirement

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the physical wristband component from the system, replacing it with direct camera-based wrist detection. The indexing function previously performed by physical wristbands is now performed by image processing algorithms that detect wrist features directly from video frames, eliminating the need for physical distribution of indexing devices.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical physical wristband system with an optical-digital system. Instead of using physical markers on wristbands for tracking, the system uses computer vision algorithms to detect and track wrist features in video frames, substituting mechanical indexing with image processing and 3D parameter calculation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If physical indexing wristbands are used to enable virtual try-on, then virtual try-on capability is achieved, but ease of operation worsens due to potential incorrect usage or damaged indexing

Engineering Contradiction:

Improvevirtual try-on capabilityVSAvoiduser operation convenience

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system performs self-service by automatically detecting and tracking the user's wrist without requiring any physical wristband or user setup. The camera captures video frames and the system automatically identifies wrist features, calculates 3D parameters, and renders virtual items, making the process entirely self-service and eliminating user error related to physical wristband usage.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical physical wristband system with an optical-digital system. Instead of using physical markers on wristbands for tracking, the system uses computer vision algorithms to detect and track wrist features in video frames, substituting mechanical indexing with image processing and 3D parameter calculation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If 3D parameter calculation from video frames is used, then physical wristbands are eliminated, but measurement precision must be maintained without physical indexing markers

Engineering Contradiction:

Improveelimination of physical wristbandsVSAvoidwrist orientation and rotation accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transitions from 2D video frame analysis to 3D parameter calculation by computing three-dimensional wrist parameters (position, orientation, rotation) from two-dimensional video frames. This dimensional transformation enables accurate 3D reconstruction and virtual item rendering without requiring physical 3D markers, maintaining measurement precision through mathematical 3D parameter derivation.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent replaces the mechanical physical wristband system with an optical-digital system. Instead of using physical markers on wristbands for tracking, the system uses computer vision algorithms to detect and track wrist features in video frames, substituting mechanical indexing with image processing and 3D parameter calculation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS20250391102A13D wrist tracking

Publication Date: 2025.12.25 SNAP INC

AI summary

A wrist tracking process is provided for use in Augmented Reality (AR) applications. A computing system captures video frame tracking data of a wrist of a user and generates 3D parameter data of the user's wrist based on the video frame tracking data. The computing system generates 3D render data of a virtual item based on the 3D parameter data of the user's wrist, and 3D model data of a physical item represented by the virtual item. The computing system generates video frame AR data based on the 3D render data and the video frame tracking data. The computing system provides an AR user interface to the user based on the video frame AR data.