; xModels Tutorial 3: Three-dimensional Scenes.

; The two previous tutorials included three-dimensional
; objects, but the transformations that were applied 
; only affected two dimensions.  Transformations can,
; in fact affect all three dimensions.  This file
; discusses three-dimensional transformations and
; has more information about transformations.

animate 60  ; This will be a 61-frame animation

circle scale 8      ; The "translate" command can take three
   translate 0 0 6  ; parameters, giving changes in x,y and z.
   yrotate 0:360    ; A translation of 6 units in the z
                    ; direction moves the circle forward
                    ; six units towards the viewer.  From that
                    ; position, it is rotated 360 degrees
                    ; around the y-axis.  This sends it
                    ; towards the right and away from the 
                    ; viewer, then all the way around the
                    ; axis and back to its original position.

red

square xscale 5     ; "xscale 3" is short for "scale 3 1 1".
       ytranslate 8 ; This means "translate 0 8 0".  Similarly,
       xrotate 0:360; there are commands: yscale, zscale,
                    ; xtranslate, ztranslate, xrotate, and
                    ; zrotate.  zrotate is actually the same
                    ; as the rotate command, since it just
                    ; rotates everything around the z-axis,
                    ; which points out of the screen towards the
                    ; user.  This rectangle starts at the top
                    ; of the screen and rotates around the 
                    ; x-axis.
                    
blue

cube scale 2 translate -12:12 2:-2 -6:6
   ; A small blue cube moves from (-12,2,-6) to (12,-2,6).


green

cylinder scale 5 rotate 0:360 about line 1 1 0
   ; The cylinder rotates about the line that extends
   ; from (0,0,0) to (1,1,0).  The "rotate about line"
   ; command lets you rotate objects about lines other
   ; than the coordinate axes.