Author Topic: general coding question (extreme maths) (Read 1629 times)

Vortex · September 12, 2013, 07:11:04 PM

okay so this isn't for a project in TS, so any direct TS implementations aren't going to help me, however help is still very appreciated.

In my application I have two objects operating on a 2d environment.

Each object has an x,y coordinate, and I need to know how to point object 1 to object 2 using those x,y coordinates. This has to be done using degrees to rotate the object or radians (which i have no idea what they are or how to use them)

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Kalphiter� · September 12, 2013, 07:22:30 PM

Do you specify the rotations in degrees or radians??

Vortex · September 12, 2013, 07:28:10 PM

Quote from: Kalphiter� on September 12, 2013, 07:22:30 PM

Do you specify the rotations in degrees or radians??

either or, doesn't matter

Kalphiter� · September 12, 2013, 07:55:22 PM

1) Add both x-values (negatives are important) of the two points to create "Rx"; do the same for "Ry".

2) arctan(Ry/Rx) is the angle; correct result for proper quadrant

If Rx is zero, the angle is either 90 degrees or 270 degrees. FYI, Torque has an arctangent function that automatically corrects the angle for the quadrant.

Vortex · September 12, 2013, 08:00:21 PM

Quote from: Kalphiter� on September 12, 2013, 07:55:22 PM

1) Add both x-values (negatives are important) of the two points to create "Rx"; do the same for "Ry".

2) arctan(Ry/Rx) is the angle; correct result for proper quadrant

If Rx is zero, the angle is either 90 degrees or 270 degrees. FYI, Torque has an arctangent function that automatically corrects the angle for the quadrant.

forget i knew it

i was using tanh instead of atan

Kalphiter� · September 12, 2013, 08:01:24 PM

Quote from: Vortex on September 12, 2013, 08:00:21 PM

forget i knew it

i was using tanh instead of atan

tanh is hyperbolic tangent and I have no loving clue what it does.

Vortex · September 12, 2013, 08:10:06 PM

Quote from: Kalphiter� on September 12, 2013, 08:01:24 PM

tanh is hyperbolic tangent and I have no loving clue what it does.

neither do i dont feel too bad

Xalos · September 13, 2013, 11:59:27 AM

Turning an object on a two-dimensional plane to face another object is simple.

Code: [Select]

function turnTo(%obj, %targ)
{
   %pos = %obj.getPosition();
   %diff = vectorSub(%targ.getPosition(), %pos);
   %ang = mAtan(getWord(%diff, 0), getWord(%diff, 1));
   %obj.setTransform(%pos@" 0 0 1 "@%ang);
}

Vortex · September 13, 2013, 03:47:03 PM

so i attempted to reverse it, sort of

trying to get the x,y coordinates of an object using the angle from the other object to that object.

basically i really forgeted up

i tried to sine and cosine of the angle which from what i've seen should retrieve the x,y but they always return 0,0