An isosurface is a three-dimensional analog of an isopleth. It represents a surface of constant value (e.g. pressure, temperature, velocity, density) within a volume of space.
Isosurfaces are normally displayed using computer graphics, and are used as data visualisation methods in computational fluid dynamics (CFD), allowing engineers to study features of a fluid flow (gas or liquid) around objects, such as aircraft wings. An isosurface may represent an individual shockwave in supersonic flight, or several isosurfaces may be generated showing a sequence of pressure values in the air flowing around a wing.
In medical imaging, isosurfaces may be used to represent regions of a particular density, allowing the visualisation of internal organs, bones, etc.
Other disciplines which perform data visualisation using isosurfaces are pharmaceutical/chemical, geophysics and meteorology.
