Model - Surface functions
Every function callable as Surface.* inside an expression — an argument input, a parameter binding, a table cell. Pure: no side effects, no async.
| Function | Returns | Description | Arg | Type | Meaning |
|---|---|---|---|---|---|
Surface.area(surface) | number | Untrimmed surface area (closed form on a recovered plane / sphere / cylinder / torus, else Gauss–Legendre). Throws if trimmed. | surface | surface | the NURBS surface |
Surface.curvature(surface, u, v) | number | Mean curvature of the surface at (u, v). | surface | surface | the NURBS surface |
u | number | 0..1 along U | |||
v | number | 0..1 along V | |||
Surface.isocurve(surface, parameter, direction) | curve | Isocurve at parameter in the given direction ('u' | 'v'). | surface | surface | the NURBS surface |
parameter | number | 0..1 along the fixed direction | |||
direction | string | 'u' or 'v' (the parameter held fixed) | |||
Surface.normalAt(surface, u, v) | vector | Unit surface normal at (u, v). | surface | surface | the NURBS surface |
u | number | 0..1 along U | |||
v | number | 0..1 along V | |||
Surface.pointAt(surface, u, v) | point | Point on the surface at parameters (u, v) ∈ [0,1]². | surface | surface | the NURBS surface |
u | number | 0..1 along U | |||
v | number | 0..1 along V |