INTRODUCTION
VARIABLE DRIVEN DESIGN ENCOMPASSES
History Based Modeling
Parametric Modeling
Variational Modeling
Feature Based Design
Rules Based Systems - predecessor
A Veritable Plethora of Terms:
- Adaptive Design
- Concurrent Associativity
- Dynamic Modeling
These terms have been invented by the vendors
- many have fuzzy definitions.
See our companion paper on Understanding Variable
Driven Modeling.
WHAT IS VDD AND WHY CALL
IT THAT?
Designs that can be altered by simply altering the variables
of the problem
- Dimensions
- Feature placement
- Tables
- Equations
- External relationships
All designed to capture design intent -- are they successful?
You be the judge!
HOW IT DIFFERS HISTORICALLY . . . . . .
Explicit Modeling - defined by geometry
- Started with 2D drafting
- Migrated to 3D wireframe
- Then to 3D surfaces, describing the outside of the object
- Then to associations with 2D
- Faceted solids
- Constructive solid geometry
- Precise solids, assoc. with downstream applications
Why was an entity put there? All lacked the ability to record
design intent
THE NEW TERMS
History Based Modeling
Variable Driven Modeling
Feature Based Design
All designed to capture design intent
Constraints
- Dimensional
- Geometric
- Algebraic
- Non geometric relations
- Placement
MODELING MODES (STEPS)
Shapes created in 2D
- Sketchers
- Dimensional and geometric constraints
- Equation solvers for complex relations
- Fully versus partially constrained shapes
Shapes used to create 3D solids
- Usual complement of extrusions, sweeps, blending, revolving
Direct creation from 3D geometry
- Directly parameterize existing geometry
- Primitive vs. freeform shapes
Combining solids or adding features
- Makes simple solids more complex
- Locating features using engineer speak
- Sketches driven by geometric elements of solids
Assemblies of parts
- Positional variables
- Exporting variables among parts
VDD usage in drawings