When modeling a building the z heights are important. Is there any way to get the z height information of an element or plane - based on the current axis position?

http://vrshed.com/sketchlife/examples.html

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Sketchlife is a system which allows you to build for Second Life using SketchUp.

Most 3D modelling tools use meshes (vertices connected by edges which define faces), whereas Second Life has adopted solids, referred to as primitives, to be their indivisible building blocks. This guarantees that there won't be any stray polygons flying around, but it also prevents mesh models from being imported automatically.

The in-world modelling tools in Second Life are quite good, but they are stone age compared to the 3D modelling power tool that is SketchUp. SketchUp is free. (Thank you Google.)

Therefore, if we can't bring SketchUp to Second Life, we'll bring Second Life to SketchUp.