Idea conver STL to Solid

[kadil]

Hi,

It seems that conversion between STL and Solid Objects has been troublesome for many users and while trying unsucessfully to convert some files, I thought slicers slice stl's very quickly. Would it be possible (and a good idea) to:
1- convert the stl to gcode using Slic3r
2- import the gcode into FreeCAD
3- Sweep along the gcode path with a circle

Thoughts?

Also, since slicers can quickly process an stl into a representation of a solid, could this approach inspire better algorythm in FreeCAD?

[chrisb]

You mean you want to sweep along the GCode path with a rectangular section? I see some drawbacks with this:
1) Depending on the size of the section the object would be hollow
2) there is the danger of self intersections
3) probably most serious: I have never seen a sweep with nearly as many path segments as this would create. I doubt that FreeCAD can handle this within decent time
4) The tesselation of a mesh is already bad, the tesselation of this procedure would probably be worse.

Sorry to spoil the party, but I'm afraid that a completely different and extremely challenging approach is needed in order to get good solids, such as make a tesselated cylinder a FreeCAD cylinder again.

[kadil]

I see, that would be a large number of objects, thanks.

What about using the slicing apprach to build polygons in a plane and extrude them, usth user defined layer height. Would this number of objects be practical in FreeCAD?

I have a need, so I am probably brainstorming what everyone else tried years ago

[chrisb]

I still see the performance issue. The G-codes do not describe an area they describe just a path. This needs additional offsets and then it can be extruded to a solid. You would have a huge number of segments and a huge number of layers to fusion with a boolean union.
You may give it a try but I would guess that performance will drop significantly.

[kadil]

Sorry, i meant slice an stl file to produce the polygons, not slicing the gcode.