Hi,

The lenses are in charge of the math behind the projection of points
in 3D space onto the projection plane (and hence how those points are
rendered in screen space.)

Like Rene said, the Orthogonal lens does orthogonal/isometric
projection meaning that there is no vanishing point. Lines that are
geometrically parallel (like the opposite sides of a cube) are drawn
parallel as well (instead of skewing towards the vanishing point.)
Read more about this at http://en.wikipedia.org/wiki/Isometric_projection

The perspective lens and zoom-focus lens provide more "regular"
projections, and are usually what you want to use.

The spherical lens _does_ actually create a fish-eye effect, but
remember that the lenses only affect projection of vertices. This
means that if you render a cube with 1x1x1 segments using a spherical
lens, all lines will remain straight. If you however increase the
density of the mesh, say to 20x20x20 segments, you will be able to see
the fish-eye effect since there are more points that are projected and
distorted in the cube.

The AbstractLens class is not a lens per sé, but an abstract base
class extended by the lens implementations (other lens classes) for
shared functionality and polymorphic behavior (e.g. being able to
replace one with another.)


Cheers
/R

On Dec 4, 11:23 am, Darcey Lloyd <[email protected]> wrote:
> Hmmm... Will probably leave these alone then...
>
> Thanks Rene
>
> D
>
> On 4 December 2010 00:15, Rene Tellez <[email protected]> wrote:
>
>
>
>
>
>
>
> > I believe that *OrthogonalLens* transform the scene into Orthogonal view
> > which means that lines are parallel to each other. One usually use this for
> > to create a 2d scene since Orthogonal view doesn't portray distance between
> > objects very well. On the other hand* PrespectiveLens* are more suited for
> > 3d scenes since it draw lines from a certain point in the scene (usually the
> > camera) and distance can be better view. I don't know what the other lens
> > do.

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