Incredibly slow file, Rhino feezes, crashes - Rhino Mac

Hi there,

I was hoping someone could assist with my file which I have attached a link to. I get this quite often with files, that they make the workflow impossible or nearly impossible by being incredibly slow or simply crashing the program.

So I have this file from Digimap, I have cleared away all the unnecessary lines and block instances but it’s still so slow when I try to edit it, especially when I select everything and trying to export it. Does anyone know why? Even If I am patient enough to export to Illustrator, it is incredibly slow in illustrator too.

I hope someone could give me some tips.

Thank you !

Hi Deniel - Hmm - well, there are hundreds of thousands of curves in the file for one thing… these are also quite far from the origin - an entire town as single line segments, by the look of it. That would be slow in some cases. The objects near the origin appear to be unrelated… which parts of the file are you working with - both?

I see it is much less tractable on the mac than on Windows, though my mac is a little macbook air and the PC is a little beefier.

@Deniel_Kiss - if you select all the lines in the town plan and Join, you reduce the number of objects by an order of magnitude - that should help. It takes a while to churn through and join all the line segments, and it may not join into the polylines that you expect, but it may help the performance. Then select the joined up lines and SimplifyCrvto make all the joined lines into simple polylines. If you can get that set of lines in as correctly joined polylines to begin with, that may help as well, and you’ll have the right polylines…


Thank you Pascal for your help !
Indeed, it’s a line segment drawing of a whole borough in London. I thought too many lines can’t be the answer to the sloweness, because I have seen larger, more complex drawing running smoothly and line drawing is the simplest of all, I have seen massive masterplan 3d models running smoothly.

Having said that though, just by joining the lines helped an incredible amount, although it took a humble 20-30 minutes. I used the SimplifyCrv command and now eerything seems okay, thank you very much !

Hi Deniel - the key thing here is sheer numbers of objects - beyond a certain point it is much more efficient to have fewer complex objects than zillions of simple ones- this is mostly because of all the per-object overhead that starts to build up - object layer info, color info, material info, name, line types - all that and more per object, is much more information than the line geometry itself. So, once joined, all that extra falls away and is applied to say one polyline rather than say 100 lines. SimplifyCrv makes the joined lines (polycurves made up of lines) into simpler polylines.