Istvan, thanks a bunch for your attention and commitment . Actually it’s quite hard to explain without going into the full detail of how to make accurate helical or pseudo-helical shapes from solid planks of wood. But I will try to answer the specific question here and give background with the aid of a couple of drawings.
Firstly - sorry, I missed the feature giving line length. Thank you!
Secondly - I’ll rephrase my statement from “flattening out a curved line” to “flattening to a single plane, a line having double curvature”, which I hope is more specific.
It seems to me that what @realdrogo @Ned @DougS @Robert and I are after is the ability to take an undulating face from a Shapr 3D drawing and flatten it out onto a 2D drawing (without losing surface area as would happen with the projection tool). This would be essential in many fields such as my own, as well as that of soft furnishing, upholstery, pattern cutting, tailoring and dressmaking, sheet metalwork including panel beating and English wheel work, veneering etc etc. Even origami. Anything that takes a flat product and makes it 3d, plus as in my case the use of templates on curved solid surfaces. Here’s an effort to explain my need:
This is an overview of a stair drawn in SketchUp. (If you want to know why I hope to use Shapr3D instead, please ask and I’ll demonstrate).
The problem in this instance is that of creating the inner face of a solid timber handrail. (There are several cases in handrail design where this kind of functionality is needed).
The plan is easy to draw being in this case half of a circle. However simple side and end elevation drawings are not enough to work with in showing the upper and lower edges of the rail where they meet the face of an imaginary cylinder rising up from the plan.
What is need is a way to flatten out the cylinder so that a paper template can be printed and then applied to the edge of a plank carved to the cylindrical form.
This hopefully shows the idea:
This is how we do it now. The central line here is taken from a 3D drawing and flattened out as previously described. The circles allow relatively accurate offset lines for handrail to and bottom to be made.
In this case, because SketchUp curves are actually a series of straight lines, this allows us to flatten out the cylinder at each endpoint. However this is very time consuming and accuracy is limited because in sketchup the cylinder is actually a polyhedron. I’m hoping Shapr will make this kind of flattened projection possible.
Thanks again for your tireless work in bringing this excellent tool to maturity.