Controls: Move
mouse with left button or A key pressed to rotate.
Move
mouse with middle button or S key pressed to zoom.
To show the tangent plane, check the box
Tangent Plane.
To show the normal plane check the box
Normal Plane. The slider
Plane Angle allows to rotate the translucid normal plane, which cuts cuts the surface along the blue curve (called a
normal section).
Its curvature is the
normal curvature in the direction of the normal plane chosen. The
maximum and
minimun of the normal curvatures are called the
principal curvatures.
If the box
Princ. curv. is checked,the normal sections giving the principal curvatures are shown: these are always orthogonal. The button
Change background cyclically changes the background among a few choices. The default background is flat, but less demanding in terms of graphics resources...
Webgl applet built with the library three.js (released under the MIT license). This applet is (C) 2012, Sisto Baldo and is released under GPL.