3D Hair Model Alignment via Mask-Based Vertex Removal

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Solution Overview

Problem

Current methods for generating 3D models from video data face challenges in accurately modeling dynamic objects like hair, which can result in collisions with the head model when rendered, leading to undesirable visual artifacts due to the lack of alignment and collision detection processes.

Innovation Solution

The system generates a 3D model of a first portion of an object, such as a head, and a second portion, like hair, by using object parsing masks to align and remove vertices, ensuring the hair model abuts the head model without collision, using a process that selects key frames and refines pose information to create a 3D base model that accurately represents both parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If 3D models of dynamic objects like hair are generated from video data, then the visual realism and detail of the reconstruction are improved, but collisions with the head model occur leading to visual artifacts

Engineering Contradiction:
Improve3D model alignment precisionVSAvoidvisual artifacts from collision
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary pose refinement and alignment of the hair model with the head model before rendering. By pre-computing the transformation parameters and adjusting the hair model's pose to match the head model's orientation, the system prevents collisions from occurring during rendering, thereby eliminating visual artifacts while maintaining high visual realism

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the rendered output is analyzed for collisions between hair and head models. When collisions are detected, the pose parameters are adjusted and the rendering is repeated. This iterative feedback process continues until no collisions are present, ensuring visual fidelity while resolving the contradiction between detail and artifact prevention

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If pose information is refined to align dynamic objects with the head model, then visual fidelity is improved, but the processing complexity and computational requirements increase

Engineering Contradiction:
Improvepose alignment accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system segments the pose refinement process into distinct components: extracting pose information from key frames, computing transformation parameters, and applying adjustments to the hair model. This segmentation allows each component to be optimized independently, reducing overall processing complexity while maintaining high alignment accuracy

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies pose refinement selectively to only those regions and frames where collisions are likely to occur, rather than processing the entire model uniformly. By focusing computational resources on critical areas such as the hair-head boundary, the system achieves high alignment accuracy without the full computational cost of processing every element

Inventive Principle:
Principle #16Partial or excessive action

3Ease of operation

If 3D models are generated from single video frames, then the ease of operation and data requirements are improved, but the accuracy and completeness of the reconstruction deteriorate

Engineering Contradiction:
Improvedata acquisition simplicityVSAvoidreconstruction accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The system performs preliminary selection of key frames from the video sequence that provide the most informative views of the object. By pre-identifying and utilizing only these critical frames, the system maintains ease of operation with simple video input while achieving high reconstruction accuracy through strategic selection of the most useful data

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes parameters such as frame selection criteria, pose estimation algorithms, and model fitting approaches based on the characteristics of the input video. By adapting these parameters to optimize for single-video-input scenarios, the system achieves high reconstruction accuracy while maintaining operational simplicity

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12062130B2Object reconstruction using media data
Publication Date: 2024.08.13 QUALCOMM INC
  • US12062130B2 patent drawing
  • US12062130B2 patent drawing
  • US12062130B2 patent drawing

AI summary

Systems and techniques are provided for performing video-based activity recognition. For example, a process can include generating a three-dimensional (3D) model of a first portion of an object based on one or more frames depicting the object. The process can also include generating a mask for the one or more frames, the mask including an indication of one or more regions of the object. The process can further include generating a 3D base model based on the 3D model of the first portion of the object and the mask, the 3D base model representing the first portion of the object and a second portion of the object. The process can include generating, based on the mask and the 3D base model, a 3D model of the second portion of the object.