proc roll {} {
    global box1
    global sphr1
    global sphr2
    .c rotate $sphr1 x 1.5
    .c rotate $sphr2 x -1.5
    .c rotate $box1 y 1.5
    .c update
}

canvas3d .c -height 300 -width 300
pack .c
update

set prj [ .c create matrix -value {{2.0 0.0 0.0 0.0} {0.0 2.0 0.0 0.0} \
	{0.0 0.0 1.0 1.0} {0.0 0.0 -2.0 0.0}} ]
set wrl [ .c create matrix -value {{1.0 0.0 0.0 0.0} {0.0 1.0 0.0 0.0} \
	{0.0 0.0 1.0 0.0} {0.0 0.0 0.0 1.0}} ]
set vw [ .c create matrix -value {{1.0 0.0 0.0 0.0} {0.0 1.0 0.0 0.0} \
	{0.0 0.0 1.0 0.0} {0.0 0.0 40.0 1.0}} ]
set back [ .c create surface ]  
set view [ .c create viewport -proj $prj -world $wrl -view $vw \
	-background $back ]
update

set tiger [ .c create surface -texture tiger.ppm -ramp 1 ]
set checker [ .c create surface -texture checker.ppm -ramp 1 ]

set sphr1 [ .c create sphere -radius 10 -surface $checker ]
.c translate $sphr1 10 10 1
set sphr2 [ .c create sphere -surface $checker] 
.c scale $sphr2 5 5 5
.c translate $sphr2 -10 10 1
set box1 [ .c create box -surface $tiger -width 12 -height 12 -depth 12 ]
.c rotate $box1 x 1.5
.c rotate $box1 y 1.5
.c update

.c itemconfigure $view -viewpoint { 0 0 -5 }
.c update
button .b -text "Roll" -command roll
pack .b