Coordinates and Orientation of Polygon in 3D
Unveiling the basics of polygon in 3D! Polygon represents a plane in Euclidean space defined by three coordinates: X, Y, Z, corresponding to length, height, and depth. While 3D software lacks a standardized orientation for these coordinates, the X coordinate typically aligns parallel to the imaginary horizon, representing length. The height and depth may switch between the Y and Z axes.
Polygon Vertices and Composition
A polygon consists of a minimum of three vertices, with the potential for an infinite number theoretically. In gaming, triangular polygons (three vertices) are commonly used. Because polygon vertices may lie on more than one plane, three points in space allow only one plane to be drawn. This helps to simplify calculations and reduce distortions in the final image. However, in 3D modeling programs, rectangular polygons (four vertices) are preferred. Designers generally avoid polygons with more than five angles. When a 3D model with rectangular polygons is exported to a game engine, each rectangular polygon is automatically converted into two triangular polygons sharing two common vertices.
Polygon in 3D Software
A polygon in 3D is a mathematical abstraction, not a physical entity in the real world. It has zero thickness and just shows coordinates of the plain vertexes in three-dimensional space. Representation of these not real polygons depends just on the software. As a rule, there are three main types of polygon display: wire mesh, polygonal mesh, “pure” polygonal representation. In general, smaller polygons offer greater accuracy in depicting the original object’s shape. Yet, there is no method to infinitely increase the number of polygons. As the computer needs to recalculate the position of each visible vertex for the viewer at least 30 times per second.
The Importance of Polygon Normals
Along with its vertex coordinates, polygon in 3d also has property called – Normal. This is a vector perpendicular to one of the sides of the polygon plane. It has a direction that indicates the front side of the polygon, or rather, its beginning. Normal is essential for texture mapping and light calculations.