\( \newcommand{\vect}[1]{\boldsymbol{#1}} \newcommand{\vecA}[2]{\begin{pmatrix}#1\\#2\end{pmatrix}} \newcommand{\vecB}[3]{\begin{pmatrix}#1\\#2\\#3\end{pmatrix}} \newcommand{\vecC}[4]{\begin{pmatrix}#1\\#2\\#3\\#4\end{pmatrix}} \newcommand{\twocol}[2]{\begin{columns}\column{0.5\textwidth}#1 \column{0.5\textwidth} #2 \end{columns}} \newcommand{\centerimage}[2]{\begin{center}\includegraphics[#1]{#2}\end{center}} \newcommand{\twocolS}[0]{\begin{columns}\column{0.5\textwidth}} \newcommand{\twocolM}[0]{\column{0.5\textwidth}} \newcommand{\twocolF}[0]{\end{columns}} \)

Polygon meshes

These are often made up of triangles, and the ordering of vertices in the triangles is used to determine whether a triangle is facing the camera.

Vertices are listed in counter-clockwise order when facing the viewer, so that it is simple to test whether a triangle is facing the camera (more on this in lecture 11).

The sphere on the left shows all triangles, on the right those facing away from the camera are removed.