Unfolding or unwrapping   see ANT-ARES 
  - this is a special theoretical part in geometrics. We will consider here the method of unfolding 3d-surface areas made from metal sheets - but you can use the method of unfolding, based on the neutral fibre, for any 3d-surface area - even to desing the form of decals. There are sometimes designing problems to make complicated hollow containers from sheet metals. From math perhaps you can remember the formulas for designing special variants of simple geometric basic solid surfaces (i.e. tubular arcs, T-form tubes, Y-form tubes). So you can get the cut-templates by using this special formulas. Sometimes this formulas are integrated as "variants" in CAD-programs. But what is to do, if there are 3d-surface areas, which are total different from that simple variants? If these 3d-surface areas can be divided in triangles (i.e. they are triangulable), you will get these results manually only with large efforts. And just this method you can use now as a program running under AutoCAD. There is only one condition: The hollow container (or the 3d-surface area) must have a clear upper and lower border(3d-poly-)line and the cross-sections on any heights has to be equal (or linear-similar); in case of a closed surfaces the welding seam's location and its path must be defined clearly. After choosing the two borderlines and the welding seam in the right way, you can find the cuttings for solid-surfaces, coming from solids, which are penetrating each other.  
  But there are lots of locksmithes and plumbers, who are no owners of a CAD-system and even there are lots of designers, who dont need a special CAD-program every day. For those people it is quite useful, if they can make a short sketch of the problem - best way is in CAD of course - and send us this problem by mail or eMail. You will get your result witin the next 2 days. The result could be a scaled dimensioned drawing (on paper or disk by mail), a DWG or a DXF (by eMail or disk), or a correctly dimensioned scaled 1:1 drawing on paper up to DIN A 0 (by mail). The prices depend on our efforts, beginning at 50 Euros for one template by eMail. As mentioned, the computation of the unfolded template is based on the neutral fibre. That means: the thickness and the special material properties will not be considered. This program can be used in other industries too: for instance in glass and ceramics.