IrrLicht / 3D Geometry confusion

[disc330]

Below is the link to help understand the problem I am having:

http://www.youtube.com/watch?v=fN4hv4cd_1M

You will notice that when a bullet is fired, it seems like it fires in a random direction. It does not fire towards the centre of the screen at all.

However, these bullets are not being fired randomly, from the video you can see that they are infact being fired in a spherical range pre-determined around the character, depending on thier position. Also, you will see that when I move the mouse just slightly, the direction of the bullet eminently changes in relation to the players rotation.

I have been to several math forums asking for explanations or formulas that could help me with this, but they dont seem to work.

Here is the code I am using for this part of the program:

$NewX   =   (GetPosition($Camera, "X")  + $Distance * Cos(GetRotation($Camera,"X")) * Cos(GetRotation($Camera,"Y")))
$NewY   =   (GetPosition($Camera, "Y")  + $Distance * Sin(GetRotation($Camera,"X")) * Cos(GetRotation($Camera,"Y")))
$NewZ   =   (GetPosition($Camera, "Z")  + $Distance * Sin(GetRotation($Camera,"Y")))
$ShotAnimator = CreateFlyStraightAnimator(GetPosition($Camera, "X"), GetPosition($Camera, "Y"), GetPosition($Camera, "Z"), $NewX, $NewY, $NewZ, 2500, 0 )                                ;Thanks to WingedPanther @ CodeCall

If you have any ideas about how to fix this, please try to explain it rather than just post the answer, thanks for taking an interest in my problem. Oh, and if you need any more information just ask.

[A. Percy]

Below is the link to help understand the problem I am having:

http://www.youtube.com/watch?v=fN4hv4cd_1M

You will notice that when a bullet is fired, it seems like it fires in a random direction. It does not fire towards the centre of the screen at all.

However, these bullets are not being fired randomly, from the video you can see that they are infact being fired in a spherical range pre-determined around the character, depending on thier position. Also, you will see that when I move the mouse just slightly, the direction of the bullet eminently changes in relation to the players rotation.

I have been to several math forums asking for explanations or formulas that could help me with this, but they dont seem to work.

Here is the code I am using for this part of the program:

$NewX   =   (GetPosition($Camera, "X")  + $Distance * Cos(GetRotation($Camera,"X")) * Cos(GetRotation($Camera,"Y")))
$NewY   =   (GetPosition($Camera, "Y")  + $Distance * Sin(GetRotation($Camera,"X")) * Cos(GetRotation($Camera,"Y")))
$NewZ   =   (GetPosition($Camera, "Z")  + $Distance * Sin(GetRotation($Camera,"Y")))
$ShotAnimator = CreateFlyStraightAnimator(GetPosition($Camera, "X"), GetPosition($Camera, "Y"), GetPosition($Camera, "Z"), $NewX, $NewY, $NewZ, 2500, 0 )                                ;Thanks to WingedPanther @ CodeCall

If you have any ideas about how to fix this, please try to explain it rather than just post the answer, thanks for taking an interest in my problem. Oh, and if you need any more information just ask.

first you need convert your angle to radians to use autoit "cos" function. Something like: Cos( (2*$PI/360) * GetRotation($Camera,"X") )

[ProgAndy]

In Math.au3 there is a function called _Radian($Degrees) which does the conversion, too

[disc330]

$NewX   =  ( $StartX + $Distance * (Cos(_Radian(Mod(GetRotation($Camera,"X"),360))) * Cos(_Radian(Mod(GetRotation($Camera,"Y"),360)))))
$NewY   =  ( $StartY + $Distance * (Sin(_Radian(Mod(GetRotation($Camera,"X"),360))) * Cos(_Radian(Mod(GetRotation($Camera,"Y"),360)))))
$NewZ   =  ( $StartZ + $Distance * (Sin(_Radian(Mod(GetRotation($Camera,"Y"),360)))))

Thank you both very much.

Thats certainly progress, its not so sensitive now, however it seems that the angles are being inverted or something...

When firing a bullet at 270 radius, it will fly off towards 180... but! If I fire a bullet at 180, it doesnt go left again. Instead it goes back to the right, to 270.

The same happens when trying this with 180 and 90.

If I shoot facing 90, it goes towards 180. From 180, goes off to 90.

I'm sure there is a simple fix for it, but I know now that it isn't setting the raduis to be deducted from a preset value. =/

If you feel like helping me out again, go ahead. If not, thanks anyway for helping me so far.

EDIT: To help understand...: http://uk.youtube.com/watch?v=oy2vDG37X1Y

Edited January 18, 2009 by disc330

[A. Percy]

$NewX   =  ( $StartX + $Distance * (Cos(_Radian(Mod(GetRotation($Camera,"X"),360))) * Cos(_Radian(Mod(GetRotation($Camera,"Y"),360)))))
$NewY   =  ( $StartY + $Distance * (Sin(_Radian(Mod(GetRotation($Camera,"X"),360))) * Cos(_Radian(Mod(GetRotation($Camera,"Y"),360)))))
$NewZ   =  ( $StartZ + $Distance * (Sin(_Radian(Mod(GetRotation($Camera,"Y"),360)))))

Thank you both very much.

Thats certainly progress, its not so sensitive now, however it seems that the angles are being inverted or something...

When firing a bullet at 270 radius, it will fly off towards 180... but! If I fire a bullet at 180, it doesnt go left again. Instead it goes back to the right, to 270.

The same happens when trying this with 180 and 90.

If I shoot facing 90, it goes towards 180. From 180, goes off to 90.

I'm sure there is a simple fix for it, but I know now that it isn't setting the raduis to be deducted from a preset value. =/

If you feel like helping me out again, go ahead. If not, thanks anyway for helping me so far.

Yes! Sum 90 to angle. Cos( (2*$PI/360) * ( GetRotation($Camera,"Y") + 90 ) )