Plotting Points on a Parametric Surface
The following method retrieves coordinate values for a regularly sampled parametric surface and plots the corresponding points using a Point Data plot. The method demonstrates extracting geometry information from the underlying parameterization of a surface. The example assumes that a parametric surface geometry object has already been created.
// Sample and plot N-by-N points on a parametric surface
int N = 20;
int faceNum = 1;
 
// Update and get geometry information
model.component("comp1").geom("geom1").run("fin");
GeomSequence geom1 = model.component("comp1").geom("geom1");
GeomFeature ps1 = geom1.feature("ps1");
 
double minMaxS[] = geom1.faceParamRange(faceNum);
double minS1 = minMaxS[0];
double maxS1 = minMaxS[1];
double minS2 = minMaxS[2];
double maxS2 = minMaxS[3];
 
double s1List[] = new double[N];
double s2List[] = new double[N];
for (int k = 0; k < N; k++) {
  s1List[k] = (double) (N-1-k)/(double) (N-1)*minS1+k/(double) (N-1)*maxS1;
  s2List[k] = (double) (N-1-k)/(double) (N-1)*minS2+k/(double) (N-1)*maxS2;
}
 
double s12List[][] = new double[N*N][2];
for (int i = 0; i < N; i++) {
  for (int j = 0; j < N; j++) {
    s12List[i+N*j][0] = s1List[i];
    s12List[i+N*j][1] = s2List[j];
  }
}
double[][] XY = geom1.faceX(faceNum, s12List);
 
// Plot points
String pgTag = model.result().uniquetag("pg");
ResultFeature pg = model.result().create(pgTag, 3);
ResultFeature plot = pg.create("pt1", "PointData");
double[][] p = new double[3][N*N];
double[] color = new double[N*N];
for (int i = 0; i < N*N; i++) {
  p[0][i] = XY[i][0];
  p[1][i] = XY[i][1];
  p[2][i] = XY[i][2];
  color[i] = p[1][i];
}
plot.set("pointdata", p)
  .set("colordata", color)
  .set("coloring", "colortable")
  .set("sphereradiusscale", 1);
plot.run();
selectNode(pg);
This example is part of a collection available for download:
 www.comsol.com/model/application-programming-guide-examples-140771
The relevant file for this example is:
•
 surface_points.mph