make switch between parallel and perspective projection work for shear-warp
make switch between parallel and perspective projection work for shear-warp

git-svn-id: a0a066a1d7ce87c7a04dae20f169ad0cd8bda35d@698 04231f92-3938-0410-9931-e931ac552b4f

deskvox/deskvox,deskvox/deskvox,deskvox/deskvox,deskvox/deskvox,deskvox/deskvox