Re: [help-3dldf] Re: button-hole problem

"Laurence Finston" <[email protected]> Sat, 23 Apr 2005 20:21:14 +0200
Newsgroups gmane.comp.tex.metafont
Message-ID <[email protected]>
I wrote:

> The perspective transformation is created by taking an
> identity matrix and setting persp[2][2] = 0 and persp[2][3] = 1/distance
> (indexing starts at 0).  This is why distance may not be 0.

Sorry, this should be Focus::persp.matrix[2][2] and Focus::persp.matrix[2][3].
 Didn't mean to sow confusion.  `persp' is a `Transform' and 
`matrix' is a `Matrix', which  is a `typedef' for  `real[4][4]'.   `real' is a
`typedef' for either `float' or `double', depending on how precise you want to
be (currently `double' in my sources). 

Laurence