IVRMLExporter Interface

Provides access to members that are associated with the VRML exporter.

Product Availability

Description

Geographical coordinates usually require double floating point precision, since the number of significant digits is large.  Some graphics standards and most rendering software are not ready to handle double precision.  For instance, the VRML standard does not force VRML browsing software to accept double precision coordinates.  As a result, you may see some visual artifacts in certain VRML browsers.

Users can select the option GeoVRML so that the exported double precision coordinates can be supported by a GeoVRML browser, or regular VRML export that "translates" the data to be close to the origin of the coordinate system (0,0) so that the number of significant digits decreases and single precision numbers suffice.

In the latter case, users can further select to move the origin, meaning to shift the data coordinates to the center of the scene extent (i.e. the XY extent; the Z coordinates are not affected) if precision problem occurs in a VRML browser, or simply keep the original geographical coordinates without moving to origin.

Here're the mathematical terms for the shifting: if the center of the scene extent is Xc and Yc in geographical coordinates, then the values in the VRML file are:

XVrml = XGeographical - Xc

YVrml = YGeographical - Yc

ZVrml = ZGeographical

Members

	Name	Description
	Indentation	Indicates if VRML text is indented.
	IsYUp	Indicates if the scene's y-axis is used as the exporter's up direction.
	MoveToOrigin	Indicates if the origin of the coordinate system is in the middle of the scene.
	Quality	The quality of textures when exported to JPEG (1-100).
	SaveOnlyVisible	Indicates if only the visible items are saved.
	UseElevationGrid	Indicates if an elevation grid is used to save raster surfaces.
	UseGeoVRML	Indicates if the GeoVRML Extension is used.

Classes that implement IVRMLExporter