GH geniuses,

Once again my forehead is banging its way through the proverbial brick wall of having-looked-at-this-for-far-too-long-and-can’t-figure-it-out-on-my-own. Please help.

I’m trying to create a (3d) surface plot that combines values from a number of (2d) graphs. I’d like the logic to follow that of a phase diagram (What is a 3D phase diagram? + Example).

It’s a messy and partly redundant definition (sorry) as I’ve been playing with things back and forth, but I’ve sketched an axis system and drawn some funky (too funky) curves (cheers Daniel Christev!) that are rotated onto the (zx) and (zy) planes in a sort-of-similar fashion to the attached image of a phase diagram.

Each value along the red graph A corresponds to a value along the red graph C; each value on the blue graph B corresponds to a value on the blue graph D. But how do I plot each (xyz) surface of those values, ie how do I get my grey points to form the “correct” surface - and how do I merge those two surface into one?

Let’s say we’re designing a spaceship. The red and blue graphs are two materials we might use. The x, y, and z axes are material cost, weight, and volume, respectively (so here’s where those funky curves clearly don’t make sense, but let’s not get hung up on that). The (zx) graphs show the volume-to-cost ratio for the red and blue materials. The (zy) graphs show their volume-to-weight ratio. Looking at the diagram in top view would yield a third diagram, plotting cost against weight.

I’m struggling both with the logic that produces the final (combined) surface(s), and with the maths part.

Any takers?

Many thanks,

Magnus

190814_first pvt-surface.gh (33.0 KB)