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Progressive meshes is one of the techniques of dynamic level of detail (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.
D. Luebke, M. Reddy, J. D. Cohen, A. Varshney, B. Watson, R. Huebner: Level of Detail for 3D Graphics, Morgan Kaufmann, 2002,
Basic principle
A progressive mesh is adata structure
In computer science, a data structure is a data organization, management, and storage format that is usually chosen for efficient access to data. More precisely, a data structure is a collection of data values, the relationships among them, a ...
which is created as the original model of the best quality simplifies a suitable decimation
Decimation, Decimate, or variants may refer to:
* Decimation (punishment), punitive discipline
* Decimation (signal processing), reduction of digital signal's sampling rate
* Decimation (comics), 2006 Marvel crossover spinoff ''House of M''
* ''D ...
algorithm
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...
, 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, vertices or vertexes may refer to:
Science and technology Mathematics and computer science
*Vertex (geometry), a point where two or more curves, lines, or edges meet
*Vertex (computer graphics), a data structure that describes the position ...
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 two connected vertices and replaces them with a single vertex. Twotriangles
A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. A triangle with vertices ''A'', ''B'', and ''C'' is denoted \triangle ABC.
In Euclidean geometry, any three points, when non-collinear ...
and which were connected by the edge are also removed during this operation.
Vertex split
Vertex split (vsplit) is the inverse operation to the edge collapse that divides the vertex into two new vertices. Therefore, a new edge and two new triangles and arise.See also
* Progressive refinementReferences
{{Reflist 3D computer graphics