Hi,

I'm building a shape within another shape to create a shell. I want that shell to have set thickness, so I've set a dimension between the inner shell's top edge and the outer shell's top edge. That's enough to set the degrees of freedom to 0. What I'm seeing however, is that it's possible for lines to move even with 0 DoF.

Say I set the two edges to be parallel and have a distance between them of 2.5, with the inner shell edge "below" the outer shell edge. Everything looks good up until I try resizing the outer shell. At that point, SolveSpace may push the inner shell edge "above" the outer shell edge. The lines are still parallel and maintain their 2.5 distance, but naturally my shell no longer works.

Is there a way to make this work without setting a height for the inner shell? I was hoping to make it relative to the outer shell. I can't see how to constrain the height with an inequality. Additionally, is the reporting of 0 DoF expected in this case or should I file a bug for it?

Thanks,
Kevin