# Surfaces Module

Creates and accesses entities that represent geometric surfaces.

Geometric surfaces (`A3DSurfBase`) are a mandatory part of the topology construct that is represented by an `A3DTopoBrepData`entity.

All surfaces are defined as follows:

1. Define the canonical form of the whole surface.

2. Define the actual parameterization and the portion of surface (trimming information) (`A3DUVParameterizationData`).

3. Define the orientation and scaling of the curve using a Cartesian transformation. The transformation cannot specify mirror or non-uniform scaling transformations (see `A3DMiscCartesianTransformationData`).

   Depending on how surfaces were defined, please notice that some might have their parameterization implicitly reverted (and more especially for periodic ones).

Topics

- NURBS Surface (the base surface entity)
- Spherical Surface
- Cylindrical Surface
- Toric Surface
- Revolution Surface
- Extrusion Surface
- Offset Surface
- Plane Surface
- Blend Surface Type 1
- Blend Surface Type 2
- Blend Surface Type 3
- Conic Surface
- Cylindrical-Space Surface
- Ruled Surface
- Pipe Surface
- Transform Surface
- From Curves Surface

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