Selection Expressions for Procedural Modeling.

Area of Science:

• Computer Graphics
• Computational Geometry
• Procedural Modeling

Background:

• Current procedural modeling grammars like CGA++ rely on local string matching for shape selection.
• This local approach limits the ability to model complex structures and enforce global constraints effectively.
• Existing methods often struggle with maintaining alignment and consistent sizing in generated models.

Purpose of the Study:

• To introduce a novel procedural modeling approach utilizing selection-expressions for shape selection.
• To develop a procedural modeling language, SelEx, that facilitates selection-based modeling.
• To enable the generation of architectural and other man-made object variations while adhering to critical design constraints.

Main Methods:

• Developed a selection-expression mechanism for defining complex shape subsets within a hierarchy.
• Introduced the SelEx procedural modeling language to implement selection-based operations.
• Demonstrated the approach's capability to enforce alignment and same-size constraints by construction.

Main Results:

• Selection-expressions allow for global context-aware shape selection, overcoming limitations of local methods.
• SelEx facilitates the creation of diverse architectural facades and building variations.
• The method successfully generates models without violating alignment and sizing constraints.

Conclusions:

• Selection-expressions offer a more powerful and intuitive paradigm for procedural modeling.
• The SelEx language and selection-expression approach significantly improve constraint enforcement in procedural generation.
• This technique is applicable to architecture and extends to other man-made object modeling.