CNC does certainly have its share of nomenclature, like several other woodworking areas, and is something that is useful to learn to help understand the process, and be able to clearly ask or answer questions.
is basically a curve. It can be made up of straight lines, arcs, or bezier curves. Basically, anything that can be represented by mathematical formulas (you DO NOT need to know the math - thats what your drawing program is for!). Say for instance
has a hand drawn sketch that he wants to machine on his future CNC. He could scan his sketch, this turns it into a Bitmap - which is a bunch of different pixels. If you zoom into this, you can see every square pixel. A drawing program such as Inkscape, Adobe Illustrator, Corel Draw or some of the CNC specific programs such as ArtCAM, VCarve, Aspire or Fusion 360 can import this this bitmap image, and then either automatically (with different degrees of success) or manually allow you to create VECTORS to replace the bitmap image. The advantage of vectors is that they can be resized smoothly and with no loss of precision, and they can be used to develop a tool path for the CNC. Vectric
is a software company, that produces software such as Cut2D (~$200), Vcarve Pro (~600), and Aspire
(~$2000). These have different price points and different capabilities.
The 3D surface analog of a vector is known as a Relief
. They may be created by some of the programs above, or they can be purchased like clip art. Many files used for 3D printing can be used, and there are online collections of free ones as well. The usual format is a STL, but can be in many other forms. Vectric has its own proprietary format, as does ArtCAM, but owners of these programs can usually import or export in these other formats as well.
A relief like the fiddle and grapes is difficult to create and requires both artistry and skill to produce. Some programs can create a relief from a photograph, but these usually require some manipulation to look right. A special form of bitmap where each bit shade of gray translates directly into a height will convert and look much better.
Generally, any CNC router can carve both vector based or relief based images, it is the CAM program that creates the toolpaths that needs to be able to handle the format, the CNC hardware just does as its told. If its told to move in X, Y and Z simultaneously, it will.