anxcon opened this issue on May 19, 2005 · 23 posts
anxcon posted Thu, 19 May 2005 at 8:10 PM
oook need a math formula for a poser mat im makin trying to find the angle of a triangle (one corner) i know X length and Y length, and they intersect at 90 deg but the other 2 corners, how to find the angle? i know itll be some simple stupid formula :x
svdl posted Thu, 19 May 2005 at 8:16 PM
corner angle =atan(y/x), this will give you the corner opposite the y edge.
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wheatpenny posted Thu, 19 May 2005 at 8:17 PM Site Admin
All 3 angles of a triangle add up to 180 degrees. so the other two angle are 180 - 90= 90 degrees, so the other two angles are 45 degrees each (90 + 45 + 45 = 180).
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svdl posted Thu, 19 May 2005 at 8:40 PM
martian_manhunter: that's only true when the x length and y length are equal!
The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter
wheatpenny posted Thu, 19 May 2005 at 8:51 PM Site Admin
One of the angles is a righ angle. The only possible way to make a triangle with a right angle is if the other two angles are 45 each. If either of them was more than 45 degrees, that would force the third angle to be obtuse( and not a right-angle), and if either of them were less than 45 then that would make the third angle acute (and not a right-angle)
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svdl posted Thu, 19 May 2005 at 8:59 PM
Sorry martian_manhunter, if one angle is 90 degrees, the other two don't have to be 45 each. One at x degrees, one at (90-x) degrees is just fine. You only have to calculate one of these angles using the atan formula, the other is obtained by substraction.
The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter
anxcon posted Thu, 19 May 2005 at 9:05 PM
what is atan? (ArcTan?) which is ? :x this be a good time to say i go a C- in math? haha
anxcon posted Thu, 19 May 2005 at 9:06 PM
o and svdl is right one angle is 90 degrees the other 2 i dont know the angle for and X and Y are not same length
ScottA posted Thu, 19 May 2005 at 9:07 PM
If either one of you guys mentions "Pythagorean theorem" I'm gonna go praying mantis on y'all. ;-)
Bobasaur posted Thu, 19 May 2005 at 9:12 PM
Before they made me they broke the mold!
http://home.roadrunner.com/~kflach/
svdl posted Thu, 19 May 2005 at 9:16 PM
anxcon: atan is arctan indeed. Most programming languages have the atan function built in (Python has it in the Math module), most pocket calculators call it arctan or inverse tan.
The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter
anxcon posted Thu, 19 May 2005 at 9:16 PM
poser nodes have no arctan :x
wheatpenny posted Thu, 19 May 2005 at 9:19 PM Site Admin
Now you lost me completely. atan is what you go to Hawaii to get...
Jeff
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svdl posted Thu, 19 May 2005 at 9:23 PM
anxcon: you're right. The math functions of the shader nodes do not provide a way to calculate the angle. But do you need the angle itself, or do you need it's sine or cosine? In that case, the dot product can help you out. If you tell me what you want to do, I'll probably be able to make you a partial node setup that does the job.
The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter
anxcon posted Thu, 19 May 2005 at 9:27 PM
that little calc is like........1 part of out 100 im using P6 mat room instead of paint programs and making me some wallpaper lol my last wallpaper, 109 nodes :x this one is going to top it tan-1(x/y) works! thanks :D but now......how do i make tan-1 since no tan-1 node x_x
svdl posted Thu, 19 May 2005 at 9:37 PM
The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter
anxcon posted Thu, 19 May 2005 at 9:44 PM
i know that formula from hyperreal :x feels like an idiot cuz answer right in front of me
ashish_s_india posted Thu, 19 May 2005 at 10:13 PM
Well Guys, A very simple way would be, that the Sine of the Angles would be in the same ratio as the sides opposite to 'em. AB/AC = sin c / sin b sine = Height / Hypotenuse Hypotenuse = sqrt(HeightHeight + BaseBase)
Butch posted Thu, 19 May 2005 at 11:18 PM
Is one and one still two? I guess that my trig teacher in high school was right after all, you never know when you might need this stuff. Geez I hate when a teacher can tell you I told you so, even if she isn't around to do it!
anxcon posted Fri, 20 May 2005 at 1:27 PM
sad this is, this thread went past 2 posts :P
Jim Burton posted Fri, 20 May 2005 at 4:25 PM
ArtTan = "Angle whose Tan is" Make it clear? ;-) People have all these nifty calculators and no idea which button to push. I remember in the bad-old days when we used 12 place log tables to work out the math on this stuff.
semidieu posted Sat, 21 May 2005 at 2:32 AM
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Here is a solution from stewer... It approximate the arctan function.
Jim Burton posted Sat, 21 May 2005 at 11:51 AM
I dimly remember it(as it was a long time ago)... Some fought the yellow man with rifles, some with guns, other with math, Sitting in the back of a 3/4 truck, 12 place log-log tables in hand, writing down the numbers, Log for Tan of 9,482.93 mils, added to the line above, and so on, All done by hand, not even a adding machine. The end result located the cannon, two guns and two howitzers, mostly, If they knew where they sat they knew where to shoot. Just a clog in a vast war-machine. I, on the other hand, mostly drove a 2 1/2 ton truck. Such is the importance of good math!