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# Why PI?

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Hi, I am not that new to programming but I am new to 3d programming and it has been a very long time since I did Maths at school. In a lot of sample code (Java3d) I have been looking at, people always seem to rotate using a division of PI instead of an absolute value - why is this? Also, could anyone explain some of the basics Maths I should be learning to help me with 3d Thanks

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There isn''t any basic maths in 3D...

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ok, misuse of semantics, some of the fundamental maths in 3d

quote:
Original post by Captain Logic
There isn't any basic maths in 3D...

[edited by - Kanamit on November 6, 2003 3:50:08 AM]

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What do you mean by a "division of pi" as opposed to an "absolute value?" Do you mean something like angle *= pi / 2 instead of angle *= 1.571?

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yeah

quote:
Original post by merlin9x9
What do you mean by a "division of pi" as opposed to an "absolute value?" Do you mean something like angle *= pi / 2 instead of angle *= 1.571 ?

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For those that did as well, google up "Polyphonic C#" and occam2.

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It''s easy to understand, especially the value used there has some kind of meaning in math. In other word, it helps increasing the readability.

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In history, only steam engine and electromagnetics impelled human beings to make progress......

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quote:
Original post by Kanamit
yeah

quote:
Original post by merlin9x9
What do you mean by a "division of pi" as opposed to an "absolute value?" Do you mean something like angle *= pi / 2 instead of angle *= 1.571 ?

ok here a bit basic: sin, ocs, sinf, cosf etc all work with RAD values in your computer, so passing 360 (in degree) is senseless, because this will give you a false result. now you will have to convert the deg to RAD before passing them to sin etc (or simply calculate each angle in RAD and store it as this...). to convert RAD to deg(°) you will have to know that 2*Pi in RAD == 360 in deg (now it should be easy to convert between both).

T2k

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mmmm... i like pie.

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meh likes candy :O *not*

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