Hand-Locked Virtual Object Rendering for Low-Lag AR Interaction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing artificial reality systems struggle to efficiently render virtual objects in relation to physical objects, particularly hands, due to input and display lag, leading to obsolete frames and limited rendering rates, which complicates smooth interaction and immersion.

Innovation Solution

A system that employs hand-locked rendering techniques, using sub-frame updates based on hand and head pose tracking, allowing virtual objects to be anchored to specific points on the user's hand, with specialized APIs for applications to specify anchor points and interact with callback functions, and incorporates occlusion handling to ensure only visible portions of virtual objects are displayed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional rendering methods are used in artificial reality systems, then the system can display virtual objects, but input and display lag causes frames to become obsolete and rendering rates are limited

Engineering Contradiction:
Improveframe accuracyVSAvoidinput and display lag
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the rendering process into multiple independent components: hand pose tracking, head pose tracking, virtual object generation, and image rendering. By processing these separately and combining them, the system reduces overall processing time and eliminates bottlenecks that cause lag and frame obsolescence.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary actions by pre-generating virtual objects based on hand pose data before the actual rendering occurs. This allows the virtual objects to be ready in advance, reducing the time required during the actual rendering phase and preventing frame obsolescence due to processing delays.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If virtual objects are dynamically updated to match hand movements, then tracking fidelity improves, but computational complexity and processing time increase

Engineering Contradiction:
Improvetracking fidelityVSAvoidrendering system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the device's own sensors (cameras and tracking systems) to capture hand and head poses, and automatically processes this data to generate and render virtual objects. This self-service approach eliminates the need for external complex processing systems while maintaining high tracking fidelity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes key parameters by processing hand pose data and head pose data independently at high rates, then combining them during rendering. This parameter separation allows the system to maintain high tracking fidelity for hand movements without proportionally increasing overall system complexity.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high frame rates are achieved through sub-frame rendering, then immersion and interaction smoothness improve, but processing requirements and system complexity increase

Engineering Contradiction:
Improverendering rateVSAvoidprocessing system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system implements periodic action by updating hand pose tracking and virtual object generation at specific intervals (sub-frames) rather than continuously. This allows the system to achieve high effective rendering rates while processing data periodically, reducing overall processing requirements and system complexity.

Inventive Principle:
Principle #19Periodic action

4Ease of operation

If virtual objects are anchored to hand positions, then user interaction becomes more intuitive, but occlusion handling and rendering complexity increase

Engineering Contradiction:
Improveinteraction intuitivenessVSAvoidrendering complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary virtual hand model that represents the user's actual hand in the virtual environment. This intermediary serves as a mediator between the real hand and virtual objects, simplifying occlusion handling by allowing the system to render virtual objects relative to the virtual hand model rather than directly to the complex geometry of the actual hand.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4272057B1Hand-locked rendering of virtual objects in artificial reality
Publication Date: 2026.04.01 META PLATFORMS TECHNOLOGIES LLC
  • EP4272057B1 patent drawingFigure 1A~1B
  • EP4272057B1 patent drawingFigure 2
  • EP4272057B1 patent drawingFigure 3

AI summary

In one embodiment, a method includes, by one or more computing devices, determining, based on first tracking data, a first viewpoint of the user and a first hand pose of the user. The method may include generating a virtual object in a virtual environment based on the first hand pose and a predetermined spatial relationship between the virtual object and the hand of the user. The method may include rendering a first image of the virtual object as viewed from the first viewpoint. The method may include determining, based on second tracking data, a second viewpoint of the user and a second hand pose. The method may include adjusting the first image of the virtual object based on changes from the first hand pose to the second hand pose. The method may include rendering and displaying a second image from the adjusted first image viewed from the second viewpoint.