The current 'dim' argument in Molodenski transforms set both source and target destination. Our Molodenski transform implementation accepts a different source and target dimensions (2 or 3), but there is currently no way to pass this information in a ParameterValueGroup.
Capability to set independently source and target dimension would be leveraged by CoordinateTransformationFactory for transformations from a 3D to 2D GeographicCRS, or conversely. In current implementation, Geotools fallback on geocentric transforms when source dimension != target dimension.
Of course, those supplemental arguments would be optional and unofficial. The Geotools implementation of CoordinateOperationFactory would have to check if those arguments are available before to attempt to use them.
CodeHaus Comment From: desruisseaux - Time: Mon, 20 Jun 2005 23:02:05 -0500
Package privated SRC_DIM and TGT_DIM parameters were added but not yet used.