I wrote this equation to generate this formila, but I'm blocked by highlighted nodes

Geometry
1

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Homéomorphe (1)_2026-04-30_04-50-35
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2

Zoom in until the node headers are visible, then export the image. Right now the graph is largely unreadable.

If I had to guess, your function node isn’t outputting an actual list, so what appears to be the first yellowed node (GetItemAtIndex?) isn’t working as intended.

3

11-Homéomorphe (1)_2026-05-01_09-23-49
11-Homéomorphe (1)_2026-05-01_09-23-493658×1806 621 KB

4

Well, you have a List.Combine with no function attached to it, so, it’s outputting a null list.

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It looks like you tried to make a list where index 0 was U values, and index 1 was V values? But you’re immediately splitting the list back apart in the next step, and you don’t use the combined list anywhere else in the script.

Can’t you just do this?

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5

It still doen’t work.

6

Hi,

an example with numpy and NurbsSurface.ByPoints()

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image1102Ă—607 127 KB

import sys
import clr
clr.AddReference('ProtoGeometry')
from Autodesk.DesignScript.Geometry import *
import numpy as np

res = 50 # grid resolution
u_vals = np.linspace(0, 2 * np.pi, res)
v_vals = np.linspace(0, 2 * np.pi, res)
U, V = np.meshgrid(u_vals, v_vals)

# equation for Z values
Z = (1 - 0.5 * np.sin(U) * np.sin(V) - np.power(np.sin(V/2), 45) + np.power(np.cos(V), 2)) * \
    (1 - np.power(np.cos(U/2), 90)) * (1 - np.power(np.cos(V/2), 90))

DS_pts = []

for i in range(res):
    row = []
    for j in range(res):
        # convert numpy.float64 to float and create point
        p = Point.ByCoordinates(float(U[i, j]), float(V[i, j]), float(Z[i, j])) 
        row.append(p)
    DS_pts.append(row)

OUT  = NurbsSurface.ByPoints(DS_pts), DS_pts
7

I don’t know why it’s not working for me.

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8

What is the error message?

9

Case-sensitivity, you didn’t copy+paste the code exactly. You’re using both uppercase and lowercase U/V.

10

20260509_2026-05-09_12-20-07
20260509_2026-05-09_12-20-07912Ă—770 86.5 KB

r = 0..Math.PiTimes2..#20;
u = v = Math.RadiansToDegrees(r);
z = (1-0.5*Math.Sin(u)*Math.Sin(v)<1>-Math.Pow(Math.Sin(v/2),45)+Math.Pow(Math.Cos(v),2))<1>*(1-Math.Pow(Math.Cos(u/2),90))*(1-Math.Pow(Math.Cos(v/2),90));
NurbsSurface.ByPoints(Point.ByCoordinates(r<1>,r,z<1>));

A Design Script approach