Post search, I have not been able to find a solution to my project. Several posts were tangential to my problem.
The goal: Create a logarithmic spiral along a truncated cone surface (identical points = matching UV).
The reason: Need a stair with a steady gradient (rise/tread) along a truncated cone
What I do not want (but have): A spiral around a truncated cone. Each revolution has the same increase in height (Z) but different lengths (see screenshot). I want the opposite; a steady increase in height resulting in varying heights for each revolution due to the longer spiral curve.
The ideal solution would allow control over riser and tread but I think I can work that out once the spiral is figured out.
I look forward to learning from you. Thanks for reading this far.
Thank you for sharing your solution. Exactly what I need. I will be able to take it from here and once I have completed the script I will post it here.
Thank you for sharing your C# script solution. I have been wanting to learn C# but will be able to work with Joseph’s solution below more autonomously. I appreciate your willingness to help!
Just one thing is that unfortunately the script produces a non code-compliant stair. This is because the tread is consistent along the inner edge. A code-compliant stair requires the tread to be consistent along the midpoint of the steps.
It’s been two years since I wrote this so I have to figure it out just like anyone else. Maybe the old code isn’t correct? Here’s the way I look at the tread distance in the middle of each step:
OK, that’s a good story, my heart is moved. For future reference though, please read this:
I took a different approach that looks better though could be improved. The original code was wrong all this time and nobody noticed! I’m busy with another project so may well have missed something else in this quickie fix.
Thank you for your generosity, it is much appreciated!
While your latest amazing script looks the part, it is sadly not construction worthy however .
There is a 1mm variable between the first and last step…
I know that a consistent thread is possible, because I have achieved it manually, but the drawing process takes forever.
Anyway, I do not request that you do my job for me! What you have achieved here is amazing regardless and thanks for taking your time to reply. Grasshopper is fascinating and perhaps I will take the time to learn.
Out of interest, which country are you in where “code” requires the centre “going” (i.e. the length of the tread in the centre of the step) to be the same on every step?
I thought here in the UK the “regs” say that the centre “going” must be a minimum of 190mm and the “rise” (step height) must be the same on each step and within a specific range.
If you have a staircase that turns through 90 degrees (I think its called a winder in the UK) then the centre going is different but the rise is always the same.
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