View Full Version : finding watershed curves of NURBS surface

02 February 2008, 06:14 PM

i am searching a few inputs for a script. it's about calculation the amount of water a drainage must be able to take for landscape architecture terrains.
thus i need the information in which direction the water will flow based on the slopes of any shaped nurbs surface.

is there a way to determine the «watershed curves» (i don't know the proper word) that define the «deepest» and «highest» curves of a surface, to where the water will flow when rain's falling?

mathematically, these curves should be well defined and thus should be «calculatable»...

thanks for any hint.

02 February 2008, 02:36 PM
hehe, okay... no answer yet... seems to be a little complex...

well, i do not need the curves very precise, an approximation will do the job.

i am thinking about sampling an array of UV Positions (10 by 10 or 20 by 20 points) and use some maximum variances to find points that fulfil the needs.

even a series of locators would be enough, placed on that near-correct location that was sampled.

i am still trying to figure out the math behind the tests for each sampled point...

maybe somone has an idea ...

02 February 2008, 10:05 PM
rain some particles on the gemoetry, with no resilience/bounce or friction, and plot their paths?

02 February 2008, 01:48 AM
if you are talking about grading contours, you could intersect your nurbs "landscape" with nurbs planes evenly spaced vertically. This will create either curves on surface or independent curves...that represent the elevation contours of a topography map.

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02 February 2008, 01:48 AM
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