Zvlak

Zvlak is a term used in geometry and computer graphics to denote a horizontal cross-section of a three-dimensional shape produced by intersecting the shape with a plane perpendicular to the z-axis. In mathematical terms, the zvlak at height z0 is the set V ∩ { (x, y, z) | z = z0 } for a subset V of R3. If V is a solid, its zvlak is typically a two-dimensional curve or polygon, or a collection of such contours, depending on the boundary of V. In continuous bodies, the zvlak corresponds to a level set of the height coordinate z.

Applications of zvlak include volume rendering, medical imaging (such as CT and MRI slices), geological modeling, and 3D printing preparation where models are sliced into layers. In computer graphics, zvlak slicing is used for cross-sectional visualization, mesh analysis, and collision detection. The term is commonly used in informal or didactic contexts and is not universally standardized across disciplines; similar notions include z-slice, z-plane, and iso-z surfaces.

Etymology and usage notes: The word zvlak appears to be formed from the z-axis and vlak, a root found in several Germanic languages meaning plane or flat surface. Its usage is primarily in European teaching materials and entry-level glossaries, where it serves as an intuitive label for horizontal cross-sections of three-dimensional data.

See also: Plane (geometry), Cross-section, Slice (volume rendering), Isosurface, Volume rendering.

References: No formal global standardization; usage is largely pedagogical or context-specific.