Path: chuka.playstation.co.uk!news
From: "John Elliot" <cg98@dial.pipex.com>
Newsgroups: scee.yaroze.programming.3d_graphics
Subject: Viewpoint rotation
Date: 6 Sep 1997 19:27:50 GMT
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Hi everyone,

I've just created a demo in which you use the joypad controls to spin
around a chessboard-like model in the middle of the screen.

I did this by changing the viewpoint variables, e.g. rotate.vpx/y/z and
position.vpx/y/z by recalculating their values each time a joypad button
was pressed. In other words, the object displayed was not moved at all,
only the direction from which it was viewed.

The only problem with this is that it involved a lot of uses of cos() and
sin(), which resulted in a considerable slowdown in frame-rate, even though
my entire model was only 37 textured polygons.

Is this the only way to move the viewpoint around an object, or am I
missing some programming trick unique to yaroze? I know you can set the
hierarchy of an object, and that this might have something to do with it,
but I could do with a bit of help if this is the way to go.

If anyone has any ideas or examples, I'd be very grateful.

Thanks,

		Jon.