B.Sc. Multimedia Computing3D Modelling and Animation

Polygon Mesh Modelling

Polygons

Various primitive shapes available including spheres, cones, cubes Polygon made from collection of vertice points joined by edges Collection of edges form faces Quality of resulting surface determined by number of vertices in the

mesh Meshes can be modified by manipulating the sub-objects of the mesh

Vertex Edge Face

Meshes can be modified by editing the construction history of the mesh Meshes can be combined through Boolean operations Meshes can be extended by adding and extruding sub-object

components

Polygon: Polysphere

Faceted Smooth

Polygon Overview

A polygon is an n-sided shape, defined by its corners (vertices) and the straight lines between them (edges). When you model with polygons you usually use triangles or quadrilaterals ("quads"), although Maya supports polygons with more sides. An individual polygon is often called a face, and is thought of as the filled area defined by its vertices and edges.

Polygon CharacteristicsObject Selection Mode

Polygon sphere in Object selection mode

Polygon CharacteristicsVertex Selection Mode

Polygon sphere in vertex selection mode

Selected vertex highlighted

Polygon Characteristics

Minimal polygon sphere in vertex mode display

Polygon Sub- Selection:Vertex

Polygon Sub- Selection:Edge

Polygon Sub- Selection:Face

Polygon Move Selection:Vertex

Polygon Move Selection:Edge

Polygon Move Selection:Face

Polygon Edit History

Polygon Edit History

Planar and Non-Planar Polygons

A polygon is planar if all its points lie in a certain plane. A triangle is always planar, because its three points define a plane.

A polygon is non-planar if it has more than three vertices, and any of those vertices are not in the same plane.

Often a mesh consists only of connected polygons, however it can also be several disjoint sets of connected polygons, called shells.

Polygon Connections

Polygons can share vertices and edges with other polygons. You can use a large number of connected polygons to form shapes. A mesh is a collection of polygons (a mesh is also sometimes called a polyset or a polygonal object). A mesh can contain different types of polygons (triangles, quads, n-sided).

Often a mesh consists only of connected polygons, however it can also be several disjoint sets of connected polygons, called shells.

Edges that are not shared (they are on the outside edge of a shell) are called border edges.

Polygon:Booleans

A

B

B - A

A - B

A Union B

A Intersection B

Smoothing Methods for Polygons

Smooth :Maya modifies the topology by smoothing out vertices and their connected edges. Smooth Proxy: The same as Smooth, but with a proxy of the original object that you can use to model and animate more easily. Average Vertices: Maya averages the values of the vertices to produce a smoother surface without modifying the topology..

Smooth Proxy

Work on a simple model while a high density version automatically updates. You can reshape and animate a rough model (with fewer components to worry about) while seeing what the smoothed mesh will look like.