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  Free-flying camera Y axis movement too fast, is tangent vector calc wrong?  (Read 1173 times)
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Offline pixelprime

Junior Devvie

Medals: 3

« Posted 2013-02-20 10:33:23 »

Hi All,

I've written a camera class to handle FPS-style movement throughout the game world, but for some reason I don't seem to be traveling the correct distance along the Y axis when pointing in that direction. Here's the code that handles the calculation of 'moving forward' along the current vector:

protected void moveForward(float distance)
      // track value (for debugging)
      lastMoveForward = distance;
      speedX -= (distance * (float)Math.sin(Math.toRadians(yaw)));
      speedZ += (distance * (float)Math.cos(Math.toRadians(yaw)));
       if (flyMode) { speedY += distance * (float) Math.tan(Math.toRadians(pitch)); }

Some quick code notes:
yaw: a value between 0-359
pitch: a value clamped between -80 (looking down) and 80 (looking up)
speedX/Y/Z: values that are added to the camera's X, Y and Z positions respectively, then zeroed-out ready for the next tick.

Moving along the X and Z axes (when looking along those axes) works beautifully. The distance travelled is ~4 units per second.

However, when flyMode is switched on (for a free-flying camera), and looking up or down, the distance travelled is vastly different - more like 20-30 units per second.

Am I calculating the speed increment along the Y axis totally wrong? Or maybe a combination of them all?

Many thanks for any help anyone can offer. I'm already learning how tremendously resourceful this community can be : )
Offline DazKins
« Reply #1 - Posted 2013-02-20 12:23:12 »

You should not be using Math.tan() to calculate the new y value, You should be using Math.sin


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Offline pixelprime

Junior Devvie

Medals: 3

« Reply #2 - Posted 2013-02-20 13:10:40 »

That's perfect! Thanks for your help!
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