Camera Angle Questions...

Question

The keys w & s are used for forwards and backwards. (using sin and cos functions.)
The keys a & d rotate the character directly.
The keys z & c are used to strafe.
The Camera is currently programmed to follow directly behind the character object. Basically the transform for the camera is
change1.setTranslation(new Vector3f(xloc2,5f,zloc2));
where xloc2 is calculated to be about 10 units behind the character. The character's head is programmed to be at about 5f (y-axis). How can I program the camera to be slightly above it's current position, AND face down slightly to the character.
I tried this, but only the second rotation gets used..
change1.rotX(.5f);
change1.rotY(yrotationangle); // Makes it so your accually looking at the character
So how do I rotate x AND y, without having to calculate some sort of z rotation, preferably. Thanks

Answer 1

How can I program the camera
to be slightly above it's current position, AND face
down slightly to the character.use the TransformGroup.lookAt method, which allows you to specify where the camera is, which direction is Up, and a point that the camera should "look at" (i.e. should be located on the z-axis of the transform), along with a scale. This way, you don't have to worry about computing angles, etc. just keep track of where you want the camera to be, and where you want it to look.
I tried this, but only the second rotation gets
used..
change1.rotX(.5f);
change1.rotY(yrotationangle); // Makes it so your
accually looking at the characterthat's right. the rotX, rotY, and rotZ methods completely reinitialize the Transform (i.e. they set it to the Identity matrix) before performing the rotation.
If you always want to rotate on one axis, then follow it with a rotation on another, look into using Euler angles. The Transform3D provides a method for using those.
Or, look into that actual Rotation Matrices for X and Y rotations. You can find these all over the place on the net, including Wikipedia. Generate the matrices yourself (javax.vecmath package has an implementation for 4D matrices), then multiply them together to get the composition of both rotations.
Or, use two TransformGroups: Set a Y-axis rotation to one of them, and an X-axis rotation to the other. Set the Y-axis rotation above (or below) the X-axis rotation, and the camera beneath those. Then both rotations will take effect.
Finally, once you start getting into complicated rotations, it might be worth your while to learn about quaternions. They make rotations much easier to specify.
To prevent things from dissappearing when you get too close, set the near clipping distance closer to the camera. Set the far clipping distance farther from the camera. Clipping distances are a part of the View object. If you don't know about View objects, chances are, you're using SimpleUniverse. Then call SimpleUniverse.getViewer().getView() (I think. Something like that, anyway).
Also, you can also widen or narrow your field of view, which allows you to control how much you see WITHOUT changing your clipping distances.