Position-dependent silhouettes

[aelata]

The following example gives the expected silhouette.

// args=[-f svg -render 0]
import solids;
currentlight = nolight;
currentprojection = orthographic(dir(60, 30 - 90));
size(5cm);
int NLAT=18, NLON=36;
revolution sph = sphere(O, 0.1, n=NLAT);
draw(surface(sph, n=NLON), yellow);
draw(sph.silhouette(), black+1pt);

However, the following example gives the unexpected silhouette.

// args=[-f svg -render 0]
import solids;
currentlight = nolight;
currentprojection = orthographic(dir(60, 30 - 90));
size(5cm);
int NLAT=18, NLON=36;
revolution sph = sphere(Z, 0.1, n=NLAT);
draw(surface(sph, n=NLON), yellow);
draw(sph.silhouette(), black+1pt);