
Surface of revolution of three klothoids

The hierarchy tree of objects for the representation of a given surface S

Dandelin's spheres, concept, reality and desirable representation

The natural value for Vis

A sphere without contour and with contour

The concept of a contour point

An explicit surface and the projection of its contour line in the parameter plane

The intersection of an explicit surface and an exponential cone

Level lines on an explicit surface

The geometric definition of a double egg line

The geometric definition of a rosette

A family of curves (pnorm) and their envelope; a = 2

A family of curves (pnorm) and their envelope; a = 4

A family of curves (pnorm) and their envelope; a = 3/4

A family of curves (pnorm) and their orthogonal trajectories;
a = 1/2

A family of curves (pnorm) and their orthogonal trajectories;
a = 1

A family of curves (pnorm) and their orthogonal trajectories;
a = 4/3

A family of curves (metric) and their orthogonal trajectories

The vectors of trihedra of a helix

Vectors of curvature and osculating circles

The torsion along a nonplanar curve on a cone

Third order approximations of a helix in the osculation, normal and rectifying planes

Helix with osculating plane and osculating sphere

A curve with k(s) = c·s

A curve with k(s) = c/Ös

Orthogonal projections of lines of constant slope on a sphere and a paraboloid of rotation on to planes