sandbox/Antoonvh/iso_3D.c

    Test isolines in 3D

    This is the intended result

    #include "grid/octree.h"
    #include "view.h"
    #include "iso3D.h"
    
    scalar s[];
    
    int main() {
      X0 = Y0 = Z0 = -L0/2;
      init_grid (16);
      refine (x < 0 && level < 5);
      unrefine (z < 0 && y < 0 && level > 2);

    The function is tested under a bunch of angles

      for (double theta = 0; theta <= 3*pi; theta += 0.02) {
        foreach()
          s[] = exp(-sq(x* (1 + 0.05*sin(theta)))
    		-sq(y* (1 + 0.2 *cos(theta)))
    		-sq(z/ (1 + 0.1 *cos(theta))));
        boundary ({s});
        coord np = {sin(theta), cos(0.5*theta), sin(1.5*theta)};
        double alphap = 0.155435 + 0.2*sin(2*theta);
        view (theta = theta/10, phi = sin(theta)/4., psi = cos(theta)/8.);
        isoline2 ("s", val = 0.75 + 0.05*sin(theta),
    	      np = np, alpha = alphap, lc = {1,0,1}, lw = 3);
        isosurface ("s", 0.78 + 0.05*sin(theta));
        box();
        cells (n = np, alpha = alphap);
        save ("lines.mp4");
      }
    }