Dec 13, 2005, 02:36 PM

I've been reading ThemsAllTook excellent introduction to matrices at,

http://www.sacredsoftware.net/tutorials/...ices.xhtml

After reading the article, I understand which elements are filled out

for the various transformation matrices: translation, rotation, scaling, etc.

My question is what is the transformation matrix multiplied with?

Say I've got a cube currently drawn on my OpenGL screen. I want to

rotate it by some amount. I fill out the matrix's elements relevant to

rotation. I then take the matrix and then what? The article says:

"A transformation matrix is essentially a map from one coordinate system to another. By multiplying a vector or a set of vectors by a matrix, you apply the matrix's transformation to the vector"

Does this imply that my cube displayed on my OpenGL screen consists of a set of vectors? I was thinking that the cube was composed of a set of

vertices?

Here's something probably completely bogus. When the above statement

says, "A transformation matrix is essentially a map from one coordinate system to another" this isn't saying that each pixel coordinate on the screen is mapped

to a new pixel coordinate?

Maybe when all is said and done, I simply don't understand exactly what an openGL image consists of?

http://www.sacredsoftware.net/tutorials/...ices.xhtml

After reading the article, I understand which elements are filled out

for the various transformation matrices: translation, rotation, scaling, etc.

My question is what is the transformation matrix multiplied with?

Say I've got a cube currently drawn on my OpenGL screen. I want to

rotate it by some amount. I fill out the matrix's elements relevant to

rotation. I then take the matrix and then what? The article says:

"A transformation matrix is essentially a map from one coordinate system to another. By multiplying a vector or a set of vectors by a matrix, you apply the matrix's transformation to the vector"

Does this imply that my cube displayed on my OpenGL screen consists of a set of vectors? I was thinking that the cube was composed of a set of

vertices?

Here's something probably completely bogus. When the above statement

says, "A transformation matrix is essentially a map from one coordinate system to another" this isn't saying that each pixel coordinate on the screen is mapped

to a new pixel coordinate?

Maybe when all is said and done, I simply don't understand exactly what an openGL image consists of?