Getting a co-linear points error for 3-pt arc when the pts aren't co-linear

Hi, I'm currently following Daniel Christev's excellent tutorial here:

https://www.youtube.com/watch?v=gHfFi64MPhU&list=PLXekJiZsSipDG...

However, I'm getting an error in the middle of it while trying to construct 3 pt arcs saying that it can't be done due to the points being co-linear, which I'm confused about because they don't seem to be co-linear at all.

This however, doesn't stop the arcs from being drawn, but the error does prevent the further steps from working.

I've attached the gh files, thanks very much!

Attachments:

twisty corridor.gh, 23 KB

Replies to This Discussion

Permalink Reply by Mohamed Naeim on June 24, 2016 at 7:42pm

from the image, it seem like the following component is just deactivated

just right-click or middle MB clicked and activate

Permalink Reply by Joseph Oster on June 24, 2016 at 8:29pm

I won't try to debug this but can tell you that the error message refers to just one arc at the very end of the list - see panel. The blue circles are the 'Arcs' as displayed by a debug tool I included (attached) that allows you to select both a branch in a tree and an item in the list for that branch. If you move the 'path indx' slider toward zero, the arcs become segments instead of full circles, as intended. This last one is an edge case bug of some sort.

P.S. I disabled preview of the 'Arc' component to avoid conflict with my 'Tree/List Viewer' debug tool, which wasn't necessary. Right click the 'Arc' component and re-enable 'Preview'.

Attachments:

twistycorridor_2016_Jun24a.gh, 34 KB

Permalink Reply by Joseph Oster on June 24, 2016 at 9:08pm

I cheated. Instead of finding and fixing the problem, I used 'Shift' (-3 with 'W (Wrap)' set to False) on the flattened list of joined curves... Flattened because that's what 'Loft' requires and "-3" because those are the un-joined curve segments of the last station.

I don't see any point in using 'Extrude' after 'Loft'?

Attachments:

twistycorridor_2016_Jun24b.gh, 32 KB

Permalink Reply by Alan P on June 25, 2016 at 1:27am

Joseph, thanks so much for your help, as soon as you identified the problem, I figured out what happened.

All I had to do was change the variables that defined the arc at the start, so that the end points of the last arc weren't at the same point.

That debug tool is super useful, thanks again!

Permalink Reply by Joseph Oster on June 25, 2016 at 6:30am

I see - very good! Pretty cool tutorial project, based on your results (I didn't watch the video). That 'Tree/List Viewer' debug tool has been very helpful to me in understanding Grasshopper. Enjoy

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