In article <MPG.226e18be342be9fb98b767@[EMAIL PROTECTED]
>,
Rob Morley <nospam@[EMAIL PROTECTED]
> wrote:
> In article <4803fff1$0$22229$4c368faf@[EMAIL PROTECTED]
>, krishnananda
> k@[EMAIL PROTECTED]
says...
> > In article <tcb704dutte32pjs3cc602rstt8dfvbqn9@[EMAIL PROTECTED]
>,
> > tony cooper <tony_cooper213@[EMAIL PROTECTED]
> wrote:
> >
> > > Go back to the beginning.
> >
> > Speaking of which, has anyone heard from the OP amidst all this
> > geometric chatter (both Euclidean and Non-Euclidean)?
> >
> > What was the (original) question?
> >
> He wanted this translated into comprehensible English:
> //
> Camera plane.....The camera plane is a horizontal line that runs
> directly across the camera position as it relates to the positon of the
> subject. The subject is at the center of a circle and the camera is at
> the outside edge of the circle so we are able to move lights around an
> invisible circle at different degrees
> //
This appears to be very similar to several sites having 3-D graphics
programming tutorials. One key is that while in photography the film
plane's location is completely independent of the subject's location, in
3-D programming the "camera" (bundle of behaviors) is intimately
connected to the subject. The line through the axis of the lens defaults
to pointing directly at the subject unless specifically programmed
otherwise.
OpenGL:
<http://www.falloutsoftware.com/tutorials/gl/gl0.htm>
Panda3D:
<http://panda3d.org/wiki/index.php/Lenses_and_Field_of_View>
The terminology used in 3-D programming while similar to that used in
photography usually has markedly different meanings, in context. 3-D has
such things as camera planes, viewing planes, clipping planes, viewing
distances, etc. Much of it combines classical perspective drawing
concepts with multivariable (matrix) algebra and trigonometry.
"Camera" and "lights" in 3-D programming have very different meanings
than in photography, primarily because the terms are used as metaphors
to help understand the higher mathematics, and the "objects" are really
sets of behaviors. Some rendering algorithms like Phong shading (used in
games) vastly simplify things photographers take for granted such as the
inverse square law. Ray Tracing is much more computationally intensive
as it not only includes the inverse-square law but also models the
refractive and reflective indices of real-world materials.
I recommend looking at the classic "Handbook of Mathematics" by
Bronshtien, Semendyayev, Musiol, and Muehlig, pp. 128 - 179, Chapter 3
"Geometry". This covers elementary plane geometry, alternate derivations
of polygons and circles, applications to triangulation and surveying,
stereometry, polyhedra, curved solids, non-euclidian coordinate systems,
spherical trigonometry, orthodromes, and loxodromes.
Anyone with a basic high-school geometry and algebra background should
be able to understand the discussions and diagrams if not all of the
equations and formulae.
--k
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