6.3 Patches

A Patch is a mechanism in RESQML that lets you specify topology and geometry to define independent parts of one representation; together all patches belonging to a representation constitute the entire representation. Using Patches is a way to hierarchically organize a representation into several parts, because inside a representation you have an ordered list of patches (each patch containing some elements). For example, the triangulated representation of a horizon may consist of 10 triangulated patches. To correctly order the geometry or properties on this representation, the software importing or reading that horizon must know the indices within each of the 10 triangulated patches AND how the 10 triangulated patches are sequenced.

All classes with "patch" in their name (e.g. NodePatch, PolylineSetPatch, Grid2DPatch, etc.) have a patch index, which is explicitly defined by the patch index inherited from the Patch object. Recommended usage is for the patch index to be identical to the order in which that patch object appears in a RESQML file. For instance, the first NodePatch would have a patch index of 0, the second a patch index of 1, etc. This order is used to uniquely sequence the elements of the patches. (The use of an explicit patch index definition is expected to be replaced by an implicit definition based on the object order in a future version of RESQML.)

• Exact usage of Patches may vary depending on the part of the RESQML model in which you are working (e.g., earth models or 3D grids). Additional details are included in relevant sections of this document.
• For the differences between Patches and subrepresentations, see RESQML-000-147-0-C-sv2010.html#RESQML_c_147__GUID-D7147C7F-2017-0008-W2DP-00000000001B .