Polygon Mesh Generation with Iterative Vertex Position Refinement

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Solution Overview

Problem

Existing techniques for generating polygon meshes from surface data, particularly when the data is provided in formats like occupancy or density values, often result in inaccurate approximations due to non-linear variations along voxel edges or lack of distance functions, leading to inefficiencies and resource consumption.

Innovation Solution

The use of successive over-relaxation techniques to iteratively adjust vertex positions in a mesh, combined with root-finding methods and interpolation, to reduce errors and improve mesh accuracy, ensuring deterministic and memory-efficient results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If standard techniques are used to approximate mesh from surface data, then the process is simple and fast, but the accuracy of surface approximation deteriorates

Engineering Contradiction:
Improvesurface approximation accuracyVSAvoidmesh generation process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by first establishing initial vertex positions using standard techniques like marching cubes, then using these preliminary positions as starting points for iterative refinement. The initial mesh configuration is prepared in advance to guide subsequent optimization iterations, improving accuracy without requiring complete redesign of the entire mesh generation process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback through iterative refinement processes where the mesh vertices are adjusted based on feedback from surface function evaluations. The error between the mesh representation and the actual surface is calculated, and vertex positions are modified accordingly in subsequent iterations, creating a closed-loop optimization system that continuously improves approximation accuracy.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If iterative refinement is applied to improve mesh accuracy, then surface approximation accuracy improves, but computational time and resource consumption increase

Engineering Contradiction:
Improvemesh vertex position accuracyVSAvoidcomputational time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by implementing iterative refinement selectively rather than uniformly across the entire mesh. The refinement process focuses on regions where the surface function varies non-linearly or where higher accuracy is required, while maintaining coarser resolution in regions where standard techniques already provide sufficient accuracy, thus reducing overall computational cost.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent utilizes parameter changes by dynamically adjusting the relaxation factor and iteration criteria based on convergence behavior. The relaxation factor is modified to accelerate convergence when errors are large and to ensure stability when approaching the solution, while the number of iterations is limited by predetermined criteria that balance accuracy requirements with computational efficiency.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If standard interpolation methods are used, then the process is simple, but accuracy deteriorates when surface varies non-linearly along voxel edges

Engineering Contradiction:
Improvesurface intersection location accuracyVSAvoidinterpolation process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces standard linear interpolation methods with root-finding techniques that solve the surface function equation directly. Instead of mechanically interpolating between fixed points, the system uses numerical methods to find the precise root of the surface function, providing accurate intersection locations even for non-linear variations without requiring complex manual intervention.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces root-finding techniques as an intermediary between the voxel data and the mesh vertex positions. This intermediary process evaluates the surface function at candidate points and iteratively refines the position estimate by solving for where the function equals zero, bridging the gap between discrete voxel values and continuous surface geometry with high precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS12437479B2Method and system for generating polygon meshes approximating surfaces using iteration for mesh vertex positions
Publication Date: 2025.10.07 ROBLOX CORP
  • US12437479B2 patent drawing
  • US12437479B2 patent drawing
  • US12437479B2 patent drawing

AI summary

Generating polygon meshes that approximate surfaces using iteration for mesh vertex positions. In some implementations, a method includes receiving input data that represents a surface distinguishing a volume, where a voxel grid includes the surface. Particular voxels of the voxel grid are identified, which the surface intersects. A surface-approximating mesh is generated including polygons defined by vertices in the particular voxels. Generating the mesh includes determining approximate positions of a subset of the vertices in a subset of the particular voxels, based on interpolation of locations in the voxel subset where the surface intersects the voxel subset. Errors between approximate voxel values (based on the approximate positions) and assigned voxel values of the particular voxels (based on the input data) are determined, and the approximate position of at least one vertex of the subset of the vertices is adjusted using a successive over-relaxation technique to reduce the errors.