🎉 Celebrating 25 Years of GameDev.net! 🎉

Not many can claim 25 years on the Internet! Join us in celebrating this milestone. Learn more about our history, and thank you for being a part of our community!

Lesson 09 wording

Started by
3 comments, last by nefthy 18 years, 2 months ago
First of all, thank you. I really enjoy the NeHe Tutorial on OpenGL so far. I'm currently at Lesson 09 but I find the example with the spinning room slightly confussing: "The first thing we do is spin the scene on the x axis. If we spin 90 degrees..." Aren't we rotating the scene on the y-axis to move -x "into the screen"? In the following paragraph of the lesson it continues: "because we've rotated on the y plane" My question is this, what is the difference between spinning the scene on the x axis and rotating on the y plane. If there is no difference how does glRotatef(tilt,1.0f,0.0f,0.0f) achieve a rotation on the y plane when the 1.0 coordinate is the x-parameter? Nicolai de Haan Copenhagen, Denmark
Advertisement
It's a bit hard to understand i know.
And there is probobly other ways of doing this, but this one is pretty good though, im shure you could do without the tilt rotation if you just fiddle a little with the coordinates.
Yeah, i got the same question and was surprised that someone wrote nearly the same I would probably have done :)
The rotation is obviously (if u launched the prog) 'around' the x-axis. But if it is so, the x-axis is the only one that does _not_ move. than i have to correct nehe (if i had his e-mail .. hmm): There is no exact y-plane, it is uncertain. imo the 'y,z-plane' would be better; and a rotation on the y,z-plane is the same like one _around_ the x-axis.
and the procedure 'glrotatef' does rotate by [1.param] degrees around a line (axis), defined by the origin and the second point defined by [params 2-4] , so in the example around the x-axis.
I hope this helps you, and more than lc_overlord's post, who only admits thats little hard to understand but doesnt do a try to explain...

ps: Does anyone know where the 'impressum' (contact, etc..) of nehe's production site is (maybe i still overlooked it, but i searched some time...); or simply his e-mail?
So, now i am registered, I did the last 'anonymus' post (thought I though could enter a name, but...
NeHe does no longer administer the site.
Andrew Russell is now in charge of nehe.gamedave.net so you might want to contact him with the issue.

This topic is closed to new replies.

Advertisement