3D Model Update via Graph Rewriting Rules
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Solution Overview
Problem
Current CAD systems face inefficiencies in updating modeled objects due to slow update times, recomputation of unnecessary operations, and loss of design intent, particularly when dealing with complex parts and non-Boolean operations.
Innovation Solution
A method involving graph rewriting rules that specify parts to be replaced and their replacements, along with common interfaces, is applied to the old output graph, allowing for efficient updating by performing logical operations rather than geometrical recomputations, and ensuring design intent is preserved.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional CAD systems recompute operations when updating modeled objects, then the geometry is updated correctly, but the update time increases significantly
Solution Approach 1:
The patent segments the update process by dividing operations into three categories: invariant operations (which remain unchanged), modified operations (which need updating), and intermediate operations (which connect the two). This segmentation allows the system to selectively recompute only the necessary portions rather than the entire operation history, significantly reducing update time while maintaining geometry accuracy.
Solution Approach 2:
The patent performs preliminary actions by pre-computing and storing the invariant portion of operations before the actual update occurs. By identifying and preserving operations that remain unchanged, the system prepares the geometry in advance, avoiding redundant recomputations during the update process and thus reducing overall update time.
2Loss of information
If CAD systems replay all operations from history to update a model, then the design intent is preserved, but unnecessary operations are recomputed
Solution Approach 1:
The patent segments the operation history into invariant, modified, and intermediate portions. By identifying which operations are truly necessary to recompute (only those in the modified and intermediate segments), the system preserves design intent through selective replay rather than replaying all operations, thus improving update efficiency.
Solution Approach 2:
The patent applies local quality by treating different portions of the operation history differently. Instead of uniformly replaying all operations, the system applies selective replay only to the local segment of operations that are affected by the modification, preserving design intent where needed while avoiding unnecessary recomputations elsewhere.
3Loss of information
If CAD systems use history-based modeling to maintain design intent, then design intent is preserved, but update complexity increases
Solution Approach 1:
The patent simplifies the complex history-based update process by segmenting operations into invariant, modified, and intermediate categories. This segmentation creates a structured approach that reduces update complexity while maintaining design intent, as the system only needs to track changes in the modified segment rather than managing the entire operation history.
Solution Approach 2:
The patent performs preliminary analysis to identify invariant operations before the update occurs. By pre-classifying operations and storing their invariant nature, the system reduces the complexity of the update process, as the invariant portions do not need to be re-evaluated during the actual update, thereby simplifying the overall workflow.
4Manufacturing precision
If CAD systems recompute geometry from scratch when updating, then accuracy is maintained, but computational complexity increases
Solution Approach 1:
The patent segments the geometry update process into invariant and modified portions. By identifying which geometric elements remain unchanged, the system avoids recomputing them from scratch, thereby reducing computational complexity while maintaining accuracy for the elements that do require updates.
Solution Approach 2:
The patent applies local quality by computing geometry updates only in the local regions affected by modifications rather than recomputing the entire geometry from scratch. This localized approach maintains accuracy where needed while significantly reducing overall computational complexity.
Data Source
AI summary
Provided is a computer-implemented method for updating a 3D model. The method comprises providing an operation undergone by the 3D model, an old input graph of the 3D model before undergoing the operation, an old output graph of the 3D model corresponding to an application of the operation to the old input graph, and a new input graph of the operation. The new input graph is generated as a result of a modification of the 3D model. The method also comprises computing a double push-out rewriting rule that specifies a part of the old input graph to be replaced, a part of the new input graph to replace the part of the old input graph. The rewriting rule also specifies an interface which is a part common to the part of the old input graph, the part of the new input graph, and the old output graph. The method further comprises applying the rewriting rule directly on the old output graph. This transforms the old output graph to a new output graph representing an updated 3D model of the real world object. The method is an improvement to updating a 3D model in a CAD system.