In article <3d9dbd7c$1@news.povray.org>,
 "Tom Melly" <tom### [at] tomandlucouk> wrote:

> I haven't used trace for a while now, but iirc what you want to do is check
> whether Norm.x and Norm.z are under a certain range. I think the following 
> would only place a sphere if the point was perfectly flat:

Just checking y would be easier. If it is very near 1, both x and y must 
be near 0. It is equal to the sine of the angle to a horizontal plane. 
And if it is non-0, the intersection is valid, so you don't even have to 
check for < 0, 0, 0> any more.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

Post a reply to this message