3D Point Cloud Skin Reconstruction via Facet Energy Minimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing 3D reconstruction methods face challenges in accurately forming a closed surface from parametric surfaces in 3D point clouds, often resulting in incomplete or noisy reconstructions due to complex calculations and grid-dependent solutions, which can fail with incorrect boundary optimization or missing data.

Innovation Solution

A computer-implemented method that fits a 3D point cloud with parametric surfaces, defines a partition of these surfaces into oriented facets, and determines a set of facets representing the object's skin by minimizing an energy function with a data term penalizing facet discarding and a constraint term preventing non-skin geometry, using a RANSAC algorithm and energy minimization to select kept facets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex boundary optimization operations are performed to form closed surfaces from parametric surfaces, then the completeness of surface reconstruction is improved, but the computational complexity and difficulty of the process increases

Engineering Contradiction:
Improvecompleteness of closed surface formationVSAvoidcomplexity of boundary optimization operations
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The method segments the continuous parametric surfaces into discrete oriented facets, transforming the complex continuous optimization problem into a discrete selection problem. Each facet is independently evaluated and classified as skin or non-skin geometry through energy minimization, avoiding the need for complex boundary optimization operations while ensuring closed surface formation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the problem parameters from continuous surface coordinates to discrete facet classifications (skin/non-skin geometry). By minimizing an energy function that operates on facet-level parameters rather than continuous boundary parameters, the method simplifies the optimization process while maintaining reliability in closed surface formation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If grid-based approaches are used to handle missing data and form closed surfaces, then the robustness to incomplete data is improved, but the solution becomes dependent on grid resolution and loses accuracy

Engineering Contradiction:
Improverobustness to incomplete dataVSAvoidaccuracy of surface representation
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The method dynamically adapts to incomplete data by evaluating each facet's contribution to closed surface formation through energy minimization, rather than relying on fixed grid structures. The facet-based approach allows flexible handling of missing data points while maintaining geometric accuracy, as facets can be selectively retained or discarded based on their fit to the point cloud and their role in forming closed surfaces.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention transitions from grid-based spatial discretization to facet-based geometric discretization. By working with oriented facets that directly represent surface geometry rather than grid cells, the method achieves both robustness to incomplete data and high measurement precision, eliminating the accuracy-loss trade-off inherent in grid-based approaches.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Shape

If parametric surfaces are fitted to 3D point clouds, then the smoothness and continuity of the reconstructed surface is improved, but the difficulty of determining correct boundary intersections increases

Engineering Contradiction:
Improvesmoothness of reconstructed surfaceVSAvoiddifficulty of boundary intersection detection
Core Design Contradiction:
ShapeVSDifficulty of detecting and measuring

Solution Approach 1:

The method extracts discrete oriented facets from the fitted parametric surfaces, separating the smooth surface representation from the boundary determination problem. By classifying facets as skin or non-skin geometry through energy minimization, the approach eliminates the difficulty of detecting boundary intersections while preserving the smoothness provided by parametric surface fitting.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The oriented facets serve as an intermediary between the continuous parametric surfaces and the discrete point cloud data. This facet layer maintains the smoothness of parametric surfaces while providing a discrete structure that simplifies boundary determination through energy-based classification, avoiding direct intersection detection between surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Stability of the object's composition

If optimization operations are performed on estimated boundaries to make neighboring surfaces coincide, then the continuity of the closed surface is improved, but the computational time and processing duration increases

Engineering Contradiction:
Improvecontinuity of closed surfaceVSAvoidcomputational time for boundary optimization
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The method performs preliminary classification of facets as skin or non-skin geometry through energy minimization before attempting to form closed surfaces. This preliminary action ensures that only relevant facets are considered for surface formation, eliminating the need for subsequent boundary optimization operations and significantly reducing computational time while maintaining surface continuity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention uses a simplified energy-based model that copies the essential geometric information from point clouds into facet classifications, avoiding complex boundary optimization. The energy function captures the necessary continuity constraints in a computationally efficient manner, achieving surface stability without time-consuming optimization iterations.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS10783707B2Determining a set of facets that represents a skin of a real object
Publication Date: 2020.09.22 DASSAULT SYSTEMES SA
  • US10783707B2 patent drawing
  • US10783707B2 patent drawing
  • US10783707B2 patent drawing

AI summary

The disclosure notably relates to a computer-implemented method for 3D reconstruction. The method comprises providing a 3D point cloud representing a real object. The method also comprises fitting the 3D point cloud with parametric surfaces. The method also comprises defining a partition of the parametric surfaces into oriented facets which respect intersections between the parametric surfaces. The method also comprises determining, among the oriented facets of the partition, a set of facets that represents a skin of the real object. The determining comprises minimizing an energy. The energy includes a data term and a constraint term. The data term increasingly penalizes discarding facets, as a level of fit between a discarded facet and the 3D point cloud increases. The constraint term penalizes formation of non-skin geometry by kept facets. Such a method provides an improved solution for 3D reconstruction.