Trim excess curves and make it into one close curves

[Aidea]

Hello, I need help in trimming the excess curves of the offseted curve. I’m trying to do it in a ghpython code however I’m still not achieving what I wanted to do. Is there any way to do achieve this goal?

TRIM CURVES.gh (7.0 KB)

[Quan_Li]

Join them first?

[Cumberland]

Using the Vipers components by Tang Chi:

TRIM CURVES_re.gh (9.2 KB)

P.S. The C# source-code is on Github, so maybe you can learn something from there.

[AndersDeleuran]

@Aidea

Is there any way to do achieve this goal?

You could use this method (edit: You probably need to use Extend Curve to make sure the lines intersect for that to work though).

Get outline (region) of points

Hehe, to be fair it’s like four lines of code, but indeed: [2024-07-12 08_54_54-Grasshopper - unnamed] 240712_CreateBooleanRegions_00.gh (6.8 KB) I think patching in RhinoCommon functionality that is missing/has yet to implemented in Grasshopper is an excellent reason for/occasion to pick up scripting. It’s usually very little code required and will require one to start understanding the API, which outside of learning Python/C# is really the secret sauce here! I put together a GHPython begi…

But also, you could do the polyline segment offsetting and intersecting/trimming the resulting lines in GhPython. I have a fairly simple function for that I can post when I’m back on my laptop, if you’re interested.

[AndersDeleuran]

@AndersDeleuran

But also, you could do the polyline segment offsetting and intersecting/trimming the resulting lines in GhPython. I have a fairly simple function for that I can post when I’m back on my laptop, if you’re interested.

Here’s a quick implementation, I expanded the function to take variable distances along the polyline segments:

Also note that this was written to offset many polylines at once, hence the explicit looping/Grasshopper types, which helps with performance.

Edit: Forgot to upload the file:
241015_OffsetPolylinesVariableDistance_Anders_00.gh (7.4 KB)

[Aidea]

hi! Thank you for this! This works perfectly

[Cumberland]

It is possible to make this script to work also with curves? Quite useful script but I do have a lot of of rounded curves and there this script it is not working. Thank you.

[Volker_Rakow]

I mean, I’m no programmer, but if I had to approach this problem using vanilla Grasshopper, this would be passable solution:

variable polyline offset.gh (29.7 KB)

I just don’t know how you would identify and cull the inadmissable polylines. Maybe like this?:

variable polyline offset2.gh (27.1 KB)

Something tells me though, that this won’t hold up to scrutiny. How is this problem approached from the programming side?

?

[AndersDeleuran]

@Volker_Rakow

Something tells me though, that this won’t hold up to scrutiny.

I’m not sure what you mean about scrutiny, but the component documentation clearly states that it does not support clipping.

[Volker_Rakow]

I see. Thank you. By scrutiny, I mean my script, not yours.

[AndersDeleuran]

@Cumberland

It is possible to make this script to work also with curves? Quite useful script but I do have a lot of of rounded curves and there this script it is not working

The script was developed specifically for fast/reliable offsetting of polylines (i.e. using basic vector methods and line intersections), so curves would require a different logic (e.g. using the native curve offsetting function for each polycurve segment, and then trimming these afterwards).