# Documentation Talk:Tutorial Section 3

• Jim, Thanks for making the earlier update. I noticed another place in the prism part of the tutorial where we should mention the bezier spline.
• Where we today have:
##### Teaching An Old Spline New Tricks

If we followed the section on splines covered under the lathe tutorial (see the section Understanding The Concept of Splines), we know that there are two additional kinds of splines besides linear: the quadratic and the cubic spline. Sure enough, we can use these with prisms to make a more free form, smoothly curving type of prism.

• I think it should read:
##### Teaching An Old Spline New Tricks

If we followed the section on splines covered under the lathe tutorial (see the section Understanding The Concept of Splines), we know that there are three additional kinds of splines besides linear: the quadratic, the cubic and the bezier spline. Sure enough, we can use these with prisms to make a more free form, smoothly curving type of prism.

• And one more which now reads:

#### Prism Object

The prism is essentially a polygon or closed curve which is swept along a linear path. We can imagine the shape so swept leaving a trail in space, and the surface of that trail is the surface of our prism. The curve or polygon making up a prism's face can be a composite of any number of sub-shapes, can use any kind of three different splines, and can either keep a constant width as it is swept, or slowly tapering off to a fine point on one end. But before this gets too confusing, let's start one step at a time with the simplest form of prism. We enter and render the following POV code (see file `prismdm1.pov`).

• that I think should read:

#### Prism Object

The prism is essentially a polygon or closed curve which is swept along a linear path. We can imagine the shape so swept leaving a trail in space, and the surface of that trail is the surface of our prism. The curve or polygon making up a prism's face can be a composite of any number of sub-shapes, can use any kind of four different splines, and can either keep a constant width as it is swept, or slowly tapering off to a fine point on one end. But before this gets too confusing, let's start one step at a time with the simplest form of prism. We enter and render the following POV code (see file `prismdm1.pov`).