Handle 3d geometries

Both the Shapefile and the DXF standard allow 3D coordinates in geometries. Nowadays, more and more 3D geodata files are in use. This means, the topology extension has to be prepared in some way to handle them. What happens if I try to smooth or generalize a 3D Shapefile polygon? Do the Z coordinates remain untouched/ignored? If new vertices need to be added: what Z coordinates do they get? How do topological checks work for 3D features? Do they just pretend they are 2D? It is easy to imagine two 3D geometries that have no spatial overlap but appear to overlap in a 2D projection. Should these be treated as a faulty topology? Since 3D topology is so much more complex, there seem to be only two options at the moment: 1) refuse to work on 3D layers 2) ignore Z coordinates and process 3D layers as though they were 2D In both cases, the user needs to be at least warned. Change History 11/02/09 17:09:18 changed by pmercade ¶ * owner set to vcaballero. * revisado changed. Vicente, I think that we should bear in mind this feature request, or we warn the use that gvSIG can't correct topologically a 3d layer; but if the software correct topological a layer, it does not take into consideration the coordinates Z. ----------------------------------------------- VCN creo que debiriamos al menos tener presente está feature, o bien avisamos al usuario de que gvSIG no es capaz de corregir topologicamente una capa 3D lo que si lo hace no tiene en cuenta las coordenadas "Z" ------------------------ Ticket #1271 (new feature request)

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