Similar to our 2-D discussion, to find the caustic surface, we should continue using the orthotomic surface we have obtained.
Example 17 For simplicity, we assume that the orthotomic surface of a surface S is the ellipsoid [7/5 sin u cos v, 6/5 sin u sin v, cos u], where u [member of] [0, [pi]], and v [member of] [0, 2[pi]]: Let the light source O be at the origin (0, 0, 0): The caustic surface of S relative to O, when we use the principle curvatures, is shown
The plot above makes the 3D caustic surface comprehensible.
3 General Inverses in 3-D, orthotomic and caustic surfaces
And for the third time, the conference entered the e-age with a session on smartphone authentication, with interesting papers including one on the use of caustic surfaces
to produce projection images that can be authenticated using a smartphone from the Reserve Bank of Australia.