"Adding" Surfaces

I am attempting to add the z-component of multiple surfaces to create a resulting surface. I have a routine set up that works - essentially sampling each surface by finding the intersection point of each surface with a grid of intersecting lines, and adding the z-components of those intersections together.
(See attached screenshot, ghx, and 3dm if my explanation failed :)

This process works fine for smaller or simpler surfaces. But when larger, complex surfaces are "added", the resulting SrfGrid stops giving a smooth result. Obviously, the number of sampling intersections can keep being increased, but the surface-curve (and line) intersection components get expensive pretty quickly. Does anyone have a better way of going about this?

Thanks in advance!

P.S. I tested the Surface-Line and the Surface-Curve Intersection components with the Profiler widget. They were close, but the Surface-Curve was a bit faster - so I've used that component here.

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Permalink Reply by Daniel Piker on May 10, 2010 at 4:57pm

Here's something similar I posted a while back that is maybe relevant:

http://www.grasshopper3d.com/xn/detail/2985220:Comment:46866

Permalink Reply by greg bethel on May 10, 2010 at 5:17pm

Thanks for the reply, Daniel. I believe that is almost exactly the definition I included above. Great minds, right? :)

It works wonderfully for simpler surfaces, but without a massive number of samples, it doesn't capture small, complex details very well.

Permalink Reply by Daniel Piker on May 10, 2010 at 6:12pm

But aren't you sampling both surfaces with a square grid ?
If you look at my def you'll see it is a little different as it samples one surf at the UV grid of the other.

Permalink Reply by greg bethel on May 10, 2010 at 6:27pm

I did see that, but discounted it because I am actually looking to add many surfaces. You're right though, I need to experiment to see how it will turn out if the multiple surfaces are added recursively, using the UV grid of the current sum (or new surface).

Thanks for the help - it is appreciated. I was hoping there might be another process I wasn't aware of that was better suited to this purpose, but I guess not!

Also, I've really enjoyed your work and blog.

Permalink Reply by greg bethel on May 11, 2010 at 12:50pm

I tried a variety of sampling spacing using UV grids, and unfortunately, none of them worked well for these detailed surfaces. Anyone have another idea? Thanks much.

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