IGES
IGES (Initial Graphics Exchange Specification) is a legacy standard for 2D/3D CAD data exchange. While largely superseded by STEP, IGES remains in use for compatibility with older CAD systems.
Format Summary
| Property | Value |
|---|---|
| Extensions | .igs, .iges |
| Encoding | ASCII |
| Import | |
| Export | |
| License | 3D Modeler |
| Layers | Mapped from IGES levels |
Import Options
| Option | Description | Default |
|---|---|---|
| Arc precision | Segments per 360° for curve approximation | 72 |
Export Options
| Option | Description | Default |
|---|---|---|
| Arc precision | Segments per 360° for curve approximation | 72 |
Supported IGES Entities
- Lines (entity 110)
- Circular arcs (entity 100)
- Composite curves (entity 102)
- Copious data / polylines (entity 106)
- Trimmed surfaces (entity 144) — extracted as 2D boundaries
- BREP solids — sliced to 2D cross-sections
Common Workflows
IGES → GDSII
Convert legacy mechanical or optical designs to IC mask layout.
GDSII → IGES
Export mask layout data for use in legacy mechanical CAD systems.
Technical Notes
- IGES is a fixed-format ASCII file with 80-character lines
- The 3D Modeler license bundle is required
- IGES supports both 2D wireframe and 3D solid geometry
- 3D geometry is sliced or projected to 2D during import
CLI / Command-File Options
These option keys can be used on the command line or in command files.
Export
| Key | Type | Description |
|---|---|---|
IgesOutUnits |
int | Output coordinate units |