>>I'm looking for some simple geometric formulae such as

>> distance from a point to a line segment

>> distance from a point to a bezier

>> distance from a point to an ellipse

>> how to determine whether a point is inside an ellipse

>> how to determine whether a point is inside a polygon

>> etc.

>I am also interested in any references to this information, as well as

> intersection of a line and a plane

> intersection of a line and a sphere

>I would appreciate it if someone could forward any pointers to

>such info. Thanks much in advance.

>Alex Brown

Alex,

I recently posted a long, long note on the fastest test for a point

inside a polygon. Line/plane, line/sphere, and line/quadric intersections

are covered in lots of places: SIGGRAPH 87 "Intro to Ray Tracing" Course

Notes has them all, Kay & Kajiya's "Ray Tracing Complex Scenes" in SIGGRAPH

'86 Proceedings is about the newest in a long line of sources for ray/plane

intersection, sphere & other quadrics are in Kajiya's SIGGRAPH 83 "Tutorial

on Ray Tracing" in the "State of the Art in Image Synthesis" Course Notes.

I just received some recommendations on good books on geometry for use in

computer graphics, and will list these below (haven't checked them all out

yet, though).

"A Programmer's Geometry", A. Bowyer, J. Woodwark, Butterworths Press, 1983?

- heard about from some people at Cornell's computer graphics lab as being

fairly helpful.

A bunch of recommendations came from Jeff Goldsmith at JPL:

Computational Geometry for Design and Manufacture

Faux & Pratt

--an early CAD text. It has lots of good stuff

on splines and 3D math.

Differential Geometry of Curves and Surfaces

DoCarmo

--A super text on classical differential geometry.

(Not quite the same as analytic geometry.)

CRC Standard Math Tables

--This has an awesome section on analytic geometry.

Calculus, too. Can't live without it. It is not

the same as the first part of the Chemistry and

Physics one.

Analytic Geometry

S* and Ballou

--Once was the standard college text on the subject.

That was a long time ago, but it is very easy to

read and it covers the fundamentals.

That's all, folks,

Eric Haines