Monochrome Line Drawings of 3D Objects due to the Programmability of KETpic

We propose a way of generating 3D graphics by using Computer Algebra Systems (CASs), whose outputs are obtained as a LATEX file. In particular, we concentrate on monochrome line drawings of 3D objects without halftone expression, which is categorized into the non-photorealistic rendering. For this purpose, we have developed a bundle of CASs´ macro packages, which we call KETpic. For 3D expressions, we have equipped KETpic with parallel/perspective projection, hidden skeleton elimination and ridge drawing. Combining and repeating these functions, we have obtained the other new 3D expressions. This feature implies one of the advantages of KETpic. Programmability of KETpic induced from CASs´ one leads us to assemble several macros to invent other new functions. In the present paper, we show rich expressions of monochrome line drawings with several direct results of KETpic, i.e., the stereogram viewing, and the wireframing, etc, and some examples for its programmability. Currently KETpic for Maple and KETpic for Mathematica are available.