Shape-Aware 3D Reconstruction for Camera Pose Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional 3D reconstruction techniques fail to accurately align camera poses and detect structural features, leading to inaccuracies and noise in reconstructed meshes, especially in indoor scenes with man-made structures, resulting in visually unpleasing outputs.

Innovation Solution

The method incorporates shape-aware techniques such as shape detection, shape-aware pose estimation, and shape-aware volumetric fusion, which involve detecting shapes in point clouds, updating camera poses, and performing joint optimization to generate cleaner and sharper 3D meshes by utilizing detected shapes as constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional 3D reconstruction techniques are used, then the reconstruction process is simple and fast, but the alignment accuracy of camera poses and detection of structural features deteriorates, leading to noise and errors in reconstructed meshes

Engineering Contradiction:
Improvealignment accuracy of camera posesVSAvoidcomplexity of reconstruction process
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary shape detection on depth maps before 3D reconstruction to identify structural features such as walls, floors, and ceilings. This preliminary action provides prior knowledge that guides subsequent camera pose alignment and mesh generation, improving accuracy without significantly increasing overall complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces shape-aware structural models as intermediaries between raw depth maps and final 3D meshes. These models act as mediators that constrain and guide the reconstruction process, enabling more accurate camera pose alignment and feature detection while maintaining computational feasibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If conventional 3D reconstruction techniques are used, then the processing speed is high, but the quality and visual appeal of reconstructed meshes deteriorates due to noise and errors

Engineering Contradiction:
Improvequality of reconstructed meshesVSAvoidprocessing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies shape-aware constraints locally to different structural elements (walls, floors, ceilings) during reconstruction. By imposing appropriate geometric constraints on specific regions rather than uniformly across the entire scene, the method improves local mesh quality while maintaining overall processing efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes key parameters of the reconstruction process by incorporating shape priors that modify the optimization landscape. This includes using shape-aware cost functions and constraints that guide the reconstruction toward higher quality results without requiring exhaustive search, thus balancing quality and speed.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If shape-aware techniques are incorporated, then the accuracy and visual appeal of 3D meshes is improved, but the complexity of the reconstruction process increases

Engineering Contradiction:
Improveaccuracy of structural feature detectionVSAvoidcomplexity of shape-aware processing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the 3D reconstruction process into distinct stages: shape detection from depth maps, shape-aware pose estimation, and shape-constrained mesh generation. This segmentation allows each module to be optimized independently and facilitates parallel processing, reducing the impact of increased complexity on overall system performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shape-aware system performs self-calibration and self-constraint by automatically detecting structural features and using them to guide the reconstruction process without requiring manual intervention. The detected shapes serve as self-generated constraints that improve reliability while keeping the system autonomous and manageable.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS11688138B2Methods and systems for detecting and combining structural features in 3D reconstruction
Publication Date: 2023.06.27 MAGIC LEAP INC
  • US11688138B2 patent drawing
  • US11688138B2 patent drawing
  • US11688138B2 patent drawing

AI summary

A method for updating camera poses includes receiving a set of captured depth maps associated with a scene and detecting a first shape and a second shape present in the scene. The method also includes, for each of the first shape and the second shape, creating a 3D mesh, creating a virtual camera associated with the 3D mesh, and rendering a depth map associated with the virtual camera. The method further includes identifying a subset of the captured depth maps such that each captured depth map in the subset contains at least a portion of either the first shape or the second shape. The method additionally includes updating the physical camera poses by jointly solving for the physical camera poses by optimizing an alignment between the first depth map, the second depth map, and the subset of the set of captured depth maps.