Variational CAD Editing with Local Constraint Propagation
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Solution Overview
Problem
Conventional CAD systems lack the ability to intuitively and flexibly edit 2D and 3D geometry while maintaining consistent results, as they either lack constraints or require fully constraining the entire system, which is not automated or user-friendly.
Innovation Solution
The implementation of a variational system that defines and generates desired local behaviors for moving and adjacent entities in CAD models, allowing for intuitive editing by applying basic and optional condition behaviors, and performing a variational solve to produce an edited CAD model.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CAD systems apply constraints to maintain geometric relationships, then manufacturing precision is improved, but device complexity increases due to requiring full system constraining
Solution Approach 1:
The patent segments the constraint application process by introducing a constraint propagation mechanism that divides the model into constrained entities and unconstrained entities. When an entity is moved, constraints are propagated only to affected adjacent entities rather than requiring full system constraining, thereby maintaining geometric relationship consistency while reducing system complexity
Solution Approach 2:
The patent applies local quality by implementing local behavior rules that determine how adjacent entities respond to movements based on their specific geometric relationships. Different local behaviors (e.g., maintaining tangency, parallelism, or distance) are applied locally to affected entities rather than globally to the entire model, enabling precision maintenance with reduced complexity
2Ease of operation
If conventional CAD systems allow flexible editing without constraints, then ease of operation is improved, but manufacturing precision deteriorates due to lack of geometric relationship maintenance
Solution Approach 1:
The patent implements dynamic constraint propagation that adapts to user actions. When users move entities, the system dynamically determines which constraints to propagate based on the movement type and affected entities. This allows flexible editing while automatically maintaining necessary geometric relationships, balancing ease of operation with manufacturing precision
Solution Approach 2:
The system provides self-service by automatically applying constraint propagation and local behavior rules when entities are moved. Users can freely edit the model without manually managing constraints, as the system automatically maintains geometric relationships through the variational solver and local behavior mechanisms
3Manufacturing precision
If conventional CAD systems require full system constraining to maintain precision, then manufacturing precision is improved, but productivity deteriorates due to increased complexity and time requirements
Solution Approach 1:
The patent segments the constraint propagation to only affected entities rather than the entire model. When an entity is moved, the system identifies and applies constraints only to adjacent entities that are geometrically related, significantly reducing the computational burden and time required while maintaining precision
Solution Approach 2:
The patent applies partial action by implementing optional condition behaviors that allow users to select which constraint types to apply (e.g., basic conditions vs. optional conditions). This enables the system to apply only the necessary constraints for each editing scenario, improving productivity by avoiding unnecessary constraint calculations while maintaining required precision
Data Source
AI summary
Methods for CAD editing and corresponding systems and computer-readable mediums. A method includes receiving a CAD model including a plurality of entities and receiving a user input including a selection of at least one entity and a movement of the selected entity. The method includes applying any basic condition behaviors that correspond to the user input and applying any optional condition behaviors that correspond to the user input. The method includes building a variational system to be solved based on the user input, any applied basic condition behaviors, and any optional condition behaviors. The method includes performing a variational solve on the variational system to produce an edited CAD model and storing the edited CAD model.