Offset question

He guys,

My problem looks simple but for me rather difficult to solve. I want to offset a curve (for a railing for a staircase) with al the same offset distance. If you ofset a curve in the xy plane it works perfect, but in the z dir it is more tricky, especially if your curve is more complex. Attached is an image with my problem.

I managed to script it for ´simple´curves, but still it is really buggy so i was wondering if there is a smart way of approaching this.

Attachments:

stairRaling.jpg, 725 KB

Replies to This Discussion

Permalink Reply by Chris Tietjen on November 18, 2011 at 4:04pm

Using your 'simple' case.

Chris

Attachments:

StairRailOffset.gh, 3 KB

Permalink Reply by Arie-Willem de Jongh on November 18, 2011 at 4:21pm

Thanks Chris,

unfortunatley it doesnt work if the angle for the corner is more or less then 90 degrees, also if the landings are more or less than 60(?) degrees... For the first problem maybe get a plane tangent to the individual line pieces, then if that offset work how to join the offsetted lines pieces in a proper way.

Permalink Reply by Jack Zeng on November 19, 2011 at 6:24am

Hi Arie-Willem,

I think Chris and Pieter's Definitions have got what you need already.

You just need to filter the result.

Jack

Attachments:

StairRailOffset_02.3dm, 40 KB
StairRailOffset_02.gh, 5 KB

Permalink Reply by Pieter Segeren on November 18, 2011 at 5:28pm

Hoi Arie, please test my late night approach...:

Attachments:

OffsetZ_PSG.gh, 7 KB

Permalink Reply by Pieter Segeren on November 19, 2011 at 4:45am

Good morning Arie-Willem, seems I really needed some sleep;)

Edit: I noticed last night that my first attempt failed when the stairs went further 'around a cube' if you know what I mean. You will have to use landings for it to work everywhere.

Attachments:

OffsetZ_v2_PSG.gh, 10 KB

Permalink Reply by Arie-Willem de Jongh on November 19, 2011 at 2:36pm

Thanks Pieter and Jack for your interesting approaches, The thing is that my stair is NOT bending under 90 degrees (which would make it fall onto the xz or yz plane) I was thinking of mabybe a pipe the curve and project the line in the z-dir see example. It works, but some corners are still messy. See attached. I will digg a little further on this.

Thanks again, cheers!

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