4.3 Spatial schema (ISO 19107)
141
Fig. 4.13. GM _Triangle
GM_ParametricCurveSurface
The surface patches that make up the parametric curve surfaces are all continuous
families of curves. A parametrie curve surface can be expressed by a mathematical
function.
GM_ GriddedSurface
The gridded surface (class GM _ GriddedSurface) is a
GM_ParametricCurveSurface defined from a rectangular grid in the parameter space.
The rows from this grid are control points for horizontal surface curves; the columns
are control points for vertical surface curves.
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Fig. 4.14. GM_GriddedSurface