STBuffer (geometry Data Type)
Returns a geometric object that represents the union of all points whose distance from a geometry instance is less than or equal to a specified value.
STBuffer() calculates a buffer in the same manner as BufferWithTolerance, specifying tolerance = distance * .001 and relative = false. The error between the theorectical and computed buffer is max(tolerance, extents * 1.E-7) where tolerance = distance * .001. For more information on extents, see geometry Data Type Method Reference.
A negative buffer removes all points within the given distance of the boundary of the geometry.
The following example creates a LineString geometry instance. It then uses STBuffer() to return the region within 1 unit of the instance.
DECLARE @g geometry; SET @g = geometry::STGeomFromText('LINESTRING(0 0, 4 0)', 0); SELECT @g.STBuffer(1).ToString();