Transformations

supports the application of linear transformations to objects and textures. If more than one transformation is specified, the total resulting transformation is computed and applied.

$\begin{defkey}{translate}{\evec{delta}} Translate (move) by {\em delta}. \end{defkey}$

$\begin{defkey}{rotate}{\evec{axis} $\theta$} Rotate counter-clockwise about the given axis by $\theta$\ degrees. \end{defkey}$

$\begin{defkey}{scale}{\evec{v}} Scale by {\em v}. \end{defkey}$
All three scaling components must be non-zero, else degenerate matrices will result.

$\begin{defkey}{transform}{\evec{row1} \evec{row2} \evec{row3} [\evec{delta}]} Ap... ...ation matrix. If given, {\em delta} specifies a translation vector. \end{defkey}$

Transformations should be specified in the order in which they are to be applied immediately following the item to be transformed. For example:

        /*
         * Ellipsoid, rotated cube
         */
        sphere 1. 0 0 0   scale 2. 1. 1. translate 0 0 -2.5
        box 0 0 0 .5 .5 .5
           rotate 0 0 1 45 rotate 1 0 0 45 translate 0 0 2.5

Transformations may also be applied to textures:

   plane 0 0 -4  0 0 1
     texture checker red scale 2 2 2 rotate 0 0 1 45

Note that transformation parameters may be specified using animated expressions, causing the transformations themselves to be animated. See Appendix B for further details.