create spiral from point

Hello guys,

I am quite new to Grasshopper and I am working on some simple spiral. I have set the turning radius according to the x,y coordinates from a point. However, I couldn't make the spiral starts exactly from position of the selected point. Does anyone know how to do it? Any help/comments are helpful and deeply appreciated!

spiral.gh This is the definition I have if it is helpful.

Replies to This Discussion

Permalink Reply by Hannes Löschke on March 3, 2012 at 2:10am

Find the angle between the point and the world coordiantes. Then rotate the spiral.

Angle can be defined in two directions in the circle. A is always the smaller of both. Need to determine which one to use to go through the whole circle.

Attachments:

spiral.gh, 8 KB

Permalink Reply by Terence Lin on March 3, 2012 at 10:39am

Thank you very much! That is very helpful! However, the rotation seems only works for single point. When I select multiple points, sometime the start point of the spiral is mirrored along either X axis or Y axis. The "Filter" box gives the error saying "Filter component only operate on a single filter index value." I am guessing the definition couldn't define which angle is the smallest? Any suggestion?

Permalink Reply by Hannes Löschke on March 3, 2012 at 3:52pm

You're right. Filter only works as a kind of selctor switch in the definition.

Here's a quick and dirty solution. I'm sure there is an equivalent component for what I'm doing here... just tool lazy to go and search for it. ;)

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