Re: Some vector math for computational geometry.

On Aug 31, 10:30 pm, William Elliot <ma...@xxxxxxxxxxxxxxxxxx> wrote:
On Fri, 31 Aug 2007, rsprawls wrote:
Not knowing how this group represents vectors when boldfacing isn't
possible, I'll use my own notation.

p(t) = p0 + tdv (NOTE: dv is a single variable. I need to
differentiate between the scalar and vector expression of d)
p dot n = ds (ds is the scalar expression of d)

dv (an unadvised notation) is a variable over what?

Since the forums can't do boldfacing, the notation used for vectors,
what is the alternative? Telling people and hoping they can keep it
straight?

Now, since in the next line I said ds is the scalar
expression...perhaps I'm assuming too much to no explicitly state dv
is the vector expression?


Since we want the point at where the ray/line and plane intersect, we
do some subbing and solve for t.

What plane? What's subbing?

Um, the plane of intersection? The plane expressed by the three
points that define the triangle contained within the plane.

Subbing is shorthand for substitution or substitute. Sometimes it's
sufficient to say sub rather than substitute, especially when my
handwriting is better than my typing skills (didn't have a keyboard or
typewriter when I was a boy).



(p0 + tdv) dot n = ds

What's ds? Another vector? What's n?

Forget I said anything. Disregard the remainder.

.