Clash Testing

This section provides addition options for detecting and displaying clashes between primitives and the external laser model. Before the External Geometry (XGEOM) element can be clashed the spatial occupancy map must be up to date, once the map has been built there generally is no need to regenerate it.

DESCLASH LMI [TEST {option} | DISP/LAY {display} | BATCH ON ] EXIT

{option} one of:

CELLS, EXACT/GEOMETRY

{display} one of:

CELLS, EXPAND/CELLS {off}, TIGHTBOXES, EXACT/GEOMETRY

The TEST command determines the level the clash test will take place, if CELLS the primitive will test for clash with the spatial occupancy map only (default). Using the EXACTGEOMETRY option the primitive will be clashed against the spatial occupancy map, if there is a clash then the primitive will be clashed against the laser external model. The use of EXACTGEOMETRY clash will produce a more accurate result however it will take longer to process the data.

The DISPLAY command determines the manner in which the graphical feedback of the clash will be displayed. By default the CELLS display option will be used: if there is a clash then all points within the spatial occupancy cell will be highlighted as clashing. The EXPANDCELLS option will highlight points within the spatial occupancy cell expanded by the additional offset as clashing. The TIGHTBOXES option will highlight points within the overlap between the spatial occupancy cell and the containment box for the primitive. The EXACTGEOMETRY option will only highlight the points of the laser model that clash with the primitive itself: as a result the clash display will normally be obscured by the primitive. The use of the EXACTGEOMETRY display option may reduce the performance of the display (or initial update of the display).

The BATCH ON command is intended for use only with laser model data in the cloud. Instead of sending individual primitives to the cloud for clashing, multiple primitives are sent at the same time and then clashed in one operation. This significantly speeds up clashing against cloud data. Once in this batch clash mode it cannot be turned off except by starting a new session.