Offset direction issues with parametric beam script

Hi Guys,

Im having trouble with understanding where I’m going wrong in this this parametric beam script i have written.

For the beams i have created the lines i want the geometry to follow and offset them out to each side. for some reason on the top and bottom sections of the beams, some of the lines have offset vertically, not at all or some are perfectly fine.

See below for broken or wrong direction lines:

See below for correct structure:

Now because the issue seems quite inconsistent, I cant figure out what is going wrong here. I have attached the file below, if anyone can help me understand what’s going wrong here, that would be amazing.

Parametric Roof Structure.gh (33.4 KB)

yes, weird thing with the offset. here is a quickfix with moving it x/2 in one direction, then extruding it -x.

the quickfix is also way less nodes than the initial version

Parametric Roof Structure.gh (24.6 KB)

ahh so is this just something that can happen when offsetting vs moving things in grasshopper? It can just get lost with the curves direction, a bit like when you offset a curve in rhino and suddenly it has 20x the original control points?

Moving makes much more sense. Amazing thanks for your help!

what you mention are two seperate things:

  1. it probably was something with the curve direction, but I did not take time to look into it any further. although curve direction should not matter for offsetting with a given plane.
  2. this is only a problem, when NURBS curves are offset, as NURBS curve-offsets in general cannot be represented as a NURBS curve witht the properties. so you get an NURBS interpolation of the offset polyline, as this is fast and robust.

Ahh I think I get you. Thank you for taking the time to explain it.

Can I ask, where do you begin to learn this more in depth stuff about how rhino actually works?