Re: RotateShape[Cuboid...
- To: mathgroup at smc.vnet.net
- Subject: [mg27282] Re: RotateShape[Cuboid...
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Fri, 16 Feb 2001 03:58:38 -0500 (EST)
- Organization: Universitaet Leipzig
- References: <96876j$3qr@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
have alook into the Graphics`Shapes`
source code
RotateShape[ shape_, phi_, theta_, psi_ ] :=
Block[{rotmat = RotationMatrix3D[N[phi], N[theta], N[psi]]},
shape /. { poly:Polygon[_] :> Map[(rotmat . #)&, poly, {2}],
line:Line[_] :> Map[(rotmat . #)&, line, {2}],
point:Point[_] :> Map[(rotmat . #)&, point,{1}] }
]
and you see ...
no rule for Cuboid[] and so it is not rotated at all.
Regards
Jens
roelb wrote:
>
> Hi,
> On Mathematica3 for mac, the following input produces 2 rods crossing
> with a 90° angle, as expected. That's OK.
>
> Show[Graphics3D[Cylinder[.3,1,10] ],RotateShape[
> Graphics3D[Cylinder[.3,1,10 ] ],
> 0,Pi/2,0]]
>
> But a quite similar RotateSphape input applied to Cuboids doesn't behave
> in the same manner. Why? (I expected the top Cudoid being oriented
> differently than the botton one).
>
> Show[Graphics3D[Cuboid[{-1,-1,0},{1,1,1}]] ,
> RotateShape[Graphics3D[Cuboid[{-1,-1,1},{1,1,2}]],
> 0,1,0]]
>
> The mathematica book state that cuboids faces are parallel to the axes.
> Should it means that RotateShape doesn't apply?