Spiral and point grid attraction

So, I am trying to overlap a spiral over a point grid.

I would like to draw lines (later extrusions) from the XY grid vertically (0,0,1) for each individual XY point. Each line for the XY grid should have a length similar to that of the closest point of the spiral. So in the images below, ideally the XY grid on the outer edges will have a lower line length, and towards the centre, the length of the lines would increase with the rising spiral

Could somebody help out. Any suggestions or pointing me in the right direction will be of great help.

Cheers

Fred

Attachments:

spiral_grid.gh, 48 KB

Replies to This Discussion

Permalink Reply by Ethan Gross on June 23, 2016 at 4:58pm

Hi Fred,

I believe there was a problem with your approach in that many of the spiral's points, especially those towards the center, would never qualify as 'closest' because of their heights. What I tried instead was to first project the spiral onto the xy plane and then look for the closest points to each on the grid. Then I found the distance from the grid point to the corresponding unprojected spiral point, which was your requirement. This distance was used to create a vertical pipe from each grid point. I'm sure it could still use some tweaking. -- I already tried posting this, so my apologies if you're suddenly inundated.

Attachments:

spiral_grid2.gh, 58 KB

Permalink Reply by Frederich Steenkamp on June 24, 2016 at 3:35pm

Hi Ethan,

Thank you so much for your response.

Yes, I also tried projecting the spiral to the xy plane and finding the shortest distance. But I am trying to get the points on the outer edges to have a lower z value:

(Because of their distance away from the spiral, they tend to be longer than I want them to be.

I made a rough idea of it in Rhino

I am contemplating that the answer might lie in how I structure the two lists.. Or perhaps I should assign attractor points for the spiral and then see which xy points might be affected by its approximation to the spiral (in 2d)?

Attachments:

Spiral02.3dm, 1.3 MB

Permalink Reply by Ethan Gross on June 24, 2016 at 4:27pm

Hi Fred,

To address your concerns I did a couple of things. First, I used just the z coordinate of the spiral point to determine the height, since some of those peripheral points, as you note, are far from the curve, and then I applied a formula to that height based on distance from the origin, reducing it down to some minimum.

Attachments: