Progressive meshes is one of the techniques of dynamic level of detail

Level of detail

In computer graphics, accounting for level of detail involves decreasing the complexity of a 3D object representation as it moves away from the viewer or according other metrics such as object importance, eye-space speed or position....

 (LOD). This technique was introduced by Hugues Hoppe in 1996. This method uses saving a model to the structure - the progressive mesh, which allows a smooth choice of detail levels depending on the current view. Practically, this means that it is possible to display whole model with the lowest level of detail at once and then it gradually shows even more details. Among the disadvantages belongs considerable memory consumption. The advantage is that it can work in real time. Progressive meshes could be used also in other areas of computer technology such as a gradual transfer of data through the Internet or compression.

Basic principle

Progressive meshes is a data structure which is created as the original model of the best quality simplifies a suitable decimation algorithm, which removes step by step some of the edges in the model (edge-collapse operation). It is necessary to undertake as many simplifications as needed to achieve the minimal model. The resultant model, in a full quality, is then represented by the minimal model and by the sequence of inverse operations to simplistic (vertex

Vertex (computer graphics)

A vertex in computer graphics is a data structure that describes a point in 2D or 3D space. Display objects are composed of arrays of flat surfaces and vertices define the location and other attributes of the corners of the surfaces.-Application to object models:In computer graphics, objects are...

split operation). This forms a hierarchical structure which helps to create a model in the chosen level of detail.

Edge collapse

This simplistic operation - ecol takes the edge connecting two vertices and creates the only one from it. Two triangles {v_s, v_t, v_l} and {v_t, v_s, v_r} which were connected by the edge are also removed during this operation.

Vertex split

Vertex split (vsplit) is the inverse operation to the edge colaps that divides the vertex into two new vertexes. Therefore a new edge {v_t, v_s} and two new triangles {v_s, v_t, v_l} and {v_t, v_s, v_r} arise.