For the time we have studied AutoCad we got some conclusions, and sometimes we got depressed because of them:

• It was too difficult changing lines, arches and other bidimensional shapes into 3D items that SL could understand.
• AutoCAD solids origin is not in their gravity center.
• We just had one axis to recover the block rotation (by default).
• Operations made in solids weren't applied over the solid, but they were boolean operation between several items (new solid generated).
• When a 3D rotation was applied, the solid got redrawn and it changed into a new solid. We had no way to recover that rotation (nor in dwg or SL).

After moments of discouraging we got over and we reached some solutions:

• Lines can be used as reference and we can fill them with solids (we can get their position and size).
• As the default coordinates origin doesn't fit our needs, we generate our own prims libraries.
• As we can't recover rotatiorns, we add atributes and, when we are applying a rotation in any of the axes, we have to remember to set those atributes.
• We are not going to use modifiers in AutoCad. We are going to work with simple and scaled shapes, and in case we need special shapes, we are going to import them from any other program (ie: 3DMax or Blender).

That's how Henshin was born, as a system that changes AutoCAD prims into SL Prims.