DopTree Class Reference

DOP-tree collision check algorithm. More...

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Detailed Description

DOP-tree collision check algorithm.

For an extensive explanation of the algorithms, please see my dissertation at http://www.gabrielzachmann.org/ .

The construction of a DopTree uses the FaceIterator to retrieve a list of all polygons of an OSG geometry.

Author:

Gabriel Zachmann, written May 1997, ported to OSG Jan 2001.

Compile-Time Flags:

• LEAFHANDLER - if set, each DOPtree can have it's own function for handling leaves; if not set, leaves will always be handled by intersectpoly. Setting this will cost a little memory and performance, but is useful for testing.
• SECOND_ITERATION_FOR_DIAMETER - does another iteration in order to find the pair of elementary DOPs furthes apart from each other.
• KRITERIUM - defines the algorithm for splitting a set of elementary DOPs.
• DOPTREE_NUM_ORI - number of orientations; always = class variable NumOri; needed for ifdef's in init().

Todo:

• Creation of DOP trees is very slow!
• Resolve all the TODO's in the code.
• Check if SECOND_ITERATION_FOR_DIAMETER really helps.
• Keine virtual methods (dtor)! (wg. Speicherplatz fuer vtable)
• DOP tree in 1 grosses Array speichern!
• Does performance increase, if all local variables are doubles?
• Zwei verschiedene DopNode's? eine Klasse fuer innere Knoten, eine fuer Blaetter; wg. Speicher fuer pgon, der in inneren Knoten nicht gebraucht wird! Evtl. kann man das auch durch union { d; pgon } machen.
• Instanzvariable index braucht man nicht, da das in child[1] gespeichert werden kann; Instanzvariable nvertices braucht man nicht, wenn man festlegt, dass sowieso nur 3- oder 4-ecke gespeichert werden koennen, und man pgon[3] fuer 3-ecke einfach auf MAX_UINT setzt.
• Klasse DopTree in Klasse DopNode mergen (oder umgekehrt).
• Verschiedene Farben bei DOP-Tree-Visualisierung.
• Code den Naming-Konventionen anpassen! (besonders m_var und M_Var)

Implementation:

The affine transformation for re-aligning DOPs is a separate struct, and not a bunch of instance variables of DopTree, so that the intersection test function can be made thread-safe.

Implementation:

See also vd2/y/oripoly.c for the original version of this code. Some of that has been omitted here, because it was experimental and has not proven to improve performance.

Bug:

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The documentation for this class was generated from the following file:

• ColDopTree.cpp

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