Overlapping Polygon Outline in Openscad

Question

I am totally new to openscad.

I am trying to generate two overlapping polygons (2D). I would just like to observe the outlines of both shapes at the same time.

I have managed to generate two different shapes. Although the shapes overlap, the renderer appears to show the outline of the combined shape with the inner part is filled in with colour.

How might I achieve my goal if the shapes were simply two overlapping squares?

Answer 1

I would be glad to see your code to understand exactly what you're trying to describe.

In any case, you must know first that openscad have several rendering types:

• the f5 one is the quicker and doesn't really calculates the final result, only its image on the screen (that's why you cannot export with it)
• the f6 one which does all the calculation of the points of the mesh and then render it (that's what you do to export)
• the debug ones that are similar to f5

I think f5 could be your solution but it will look a bit "glitchy" because of the superposition of the two shapes. The fact is that I don't think openscad is made for what you want to do because you can consider that all that you put in your script is in a big union() block so when you press f6 all the independent shapes are combined into one and I don't think there is a way to prevent that. I should add that I think that the 2D functions of openscad are probably made to be used with the extrude functions to make 3D volumes for which the overlapping doesn't have a lot of sense.