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05-15-2001, 03:38 AM
Hello,
I was wondering, whats the mats for making a circular movement? i need it to move in x,y,z, for example a sphere. Can anyone help?
Thanx

Gavin
05-15-2001, 04:18 AM
You mean a bit like a planet orbiting????

05-15-2001, 08:42 AM
Exactly. Acytually, eliptic orbit. is there an equation?

rts
05-15-2001, 09:11 AM
Sure.


Look up "Mysterium Cosmographicum" and "Astronomia Nova", both by Johannes Keppler, published in 1596 and 1609 respectively.

chrisATI
05-15-2001, 12:03 PM
Originally posted by Alkakios3K:
Hello,
I was wondering, whats the mats for making a circular movement? i need it to move in x,y,z, for example a sphere. Can anyone help?
Thanx

rotate desired amount then translate distance = to radius.

next frame, rotate a little more and then translate again.

this is a very simple way to get the kind of movement you've described. http://www.opengl.org/discussion_boards/ubb/smile.gif



[This message has been edited by chrisATI (edited 05-15-2001).]

05-16-2001, 12:58 AM
Ok, thank you, it works.

Gavin
05-17-2001, 01:07 AM
Some pretty complex 'mats' there Alkakios! :-)

Tim Stirling
05-17-2001, 02:04 AM
The physics/maths behind the fact that planet's orbits are eliptcal isn't known so know equation will ever be correct but there are equations that simulate it- Empirial formulae they are called I think.

j
05-17-2001, 07:02 AM
Actually, they physics behind the planets orbiting is pretty well known. It's called gravity.

For calculating the orbit of one object around another object that we assume does not move, the "empirical formulas" are perfectly accurate.

It's calculating the trajectories of multiple objects that are all exerting gravitational influences on one another that we can't do perfectly.

j

rts
05-17-2001, 07:53 AM
Originally posted by Tim Stirling:
The physics/maths behind the fact that planet's orbits are eliptcal isn't known so know equation will ever be correct but there are equations that simulate it- Empirial formulae they are called I think.


Uhm... did you miss my post? We've known about these equations for 400 years, and Kepler's laws are accurate to within a few seconds of arc.

Oy.