an unpolished unrefined quality; "the crudeness of frontier dwellings depressed her"
Variation of surface height within an imaged resolution cell A surface appears "rough" to microwave illumination when the height variations become larger than a fraction of the radar wavelength The fraction is qualitative, but may be shown to decrease with incidence angle
a way of quantifying the degree of drag on flowing water by a surface Most commonly expressed as a dimensionless Manning's number
That in general means the regular or irregular, slight geometrical deviation from a smooth surface condition
The root mean squared (RMS) microfacet slope of a Gaussian surface This is equal to the standard deviation of the surface height over the autocorrelation distance of this deviation In the anisotropic material model used in Radiance, this quantity may be given a directional component