offsetting multiple closed polylines inwards

Hey guys,

Im new to grasshopper and not sure which tool(s) to use for this one. I have huge number of closed rectangles that needs to be offsetted to create depth for the walls and floor plates(it's a section, btw). The problem is that they have different vector directions, so they offset randomly,both inwards and outwards. So I was wondering if there is a way I could split them into lists based on the their directions and offset those lists to get the desired outcome.

Thanks!!!

Attachments:

geometry to offset.png, 147 KB
offset result.png, 192 KB

Replies to This Discussion

Permalink Reply by Erick Vásquez on April 24, 2014 at 10:38pm

offset loose

Permalink Reply by Venkatesh Natarajan on April 24, 2014 at 10:48pm

thanks ... that did work better, but i still have a a few polylines offsetting the wrong way, and a few that don't offset at all.

Permalink Reply by Erick Vásquez on April 24, 2014 at 11:20pm

try this.

Attachments:

140425_offset.gh, 14 KB

Permalink Reply by Venkatesh Natarajan on April 24, 2014 at 11:42pm

still no luck :(. Isn't it possible to split the geometry into lists based on their direction? Inverting the offset distance of one of those lists should do the trick?

Permalink Reply by Mahdi Taheri on April 25, 2014 at 1:01am

this may help you

Attachments:

offset_shapes.gh, 10 KB

Permalink Reply by Venkatesh Natarajan on April 25, 2014 at 1:02am

I wish

Permalink Reply by Erick Vásquez on April 25, 2014 at 9:00am

Please attach your file.

Permalink Reply by Michael Makris on April 25, 2014 at 9:32am

Agreed. We can't really replicate what you're doing without it.

Permalink Reply by Arend on April 25, 2014 at 9:35am

Offset are different because the curves are oriented in a different direction. This can be solved using the orient curve.

If all curves are in completely different planes, this is probably not the right approach. If they're just in the xy plane, it should solve your worries.

Attachments:

flip-curves-using-guide.gh, 8 KB

Permalink Reply by RustBoy on April 25, 2014 at 10:15am

This def offsets in both directions and compares the lengths, allowing you to choose which side you want to offset. Apologies for not giving credit - I can't remember whose solution this is.

Permalink Reply by Venkatesh Natarajan on April 26, 2014 at 12:54am

I ended up used a different approach of extruding the curves in x and y directions producing strips of surfaces; then projecting the surface edges on to another surface. sorry, I couldn't upload the file here because the file size is too large. Anyway, thanks for your help guys, I really appreciate it. Learnt some interesting stuff I could use for my other assignments.