Simplify/Regularize polylines in Rhino


Is there a command that would simplify a group of closed polylines? I am working with a set of complex objects and would like to get rid of some of the rough edges. I’m wondering if there’s a command that could reduce each one to have four points. Or alternatively, a way to reduce each one to a square. Screenshot below.


Hi Paul - hard to know what in that image is a keeper and what is not - can you post a file with some bad polylines and a fixed version of these?


Hi Pascal


I’m looking for a way to regularize these shapes (visual example of what I mean by this below.) I guess other programs like ARCGIS use a polyline compression algorithm to do this.


One really simple (but not flexible) way to do it would just be able to draw a bounding box around each shape individually

Here’s a file. I tried “correcting” some using a bounding box, which works alright, but what would be really helpful is to be able to do something like “reduce all closed polylines with over 10 points to closed polylines with 10 points”

Bitmap Etch Sample.3dm (1.0 MB)

Just for reference, I’m laser etching bitmapped images to produce tactile drawings for visually impaired people, and all of the additional edges and texture makes the image a little less clean and legible, so I’m looking for a way to clean it up a bit.

Thanks for your reply,

Hi Paul - it looks like bounding boxes will do the job in this case, right? Reducing a polyline in a smart way would be tricky.


Yes! Bounding Boxes would be a good solution. I also found the Bitmap+ Plugin for Grasshopper so I’ll look into whether that can help if I want more customized geometry.

Thanks Pascal

Just solved it a bit better using Rebuild