Rotation Issue in XNA 3.0

September 6, 2008 by admin
Filed under: Xbox360 News

1	//…
2	protected override void Update(GameTime gameTime)
3	{
4	if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
5	this.Exit();
6
7	#if !XBOX
8	if (Keyboard.GetState().IsKeyDown(Keys.Escape))
9	this.Exit();
10	#endif
11
12	GamePadState gamePadStateP1 = GamePad.GetState(PlayerIndex.One);
13	GamePadState gamePadStateP2 = GamePad.GetState(PlayerIndex.Two);
14	GamePadState gamePadStateP3 = GamePad.GetState(PlayerIndex.Three);
15	GamePadState gamePadStateP4 = GamePad.GetState(PlayerIndex.Four);
16
17	#if !XBOX
18	KeyboardState keyboardState = Keyboard.GetState();
19	#endif
20
21	previousGamePadStateP1 = GamePad.GetState(PlayerIndex.One);
22	previousGamePadStateP2 = GamePad.GetState(PlayerIndex.Two);
23	previousGamePadStateP3 = GamePad.GetState(PlayerIndex.Three);
24	previousGamePadStateP4 = GamePad.GetState(PlayerIndex.Four);
25
26	terrain.rotation.X = ((gamePadStateP1.Triggers.Right / 2) - (gamePadStateP1.Triggers.Left / 2) - 1.5f);
27
28	terrain.rotation.Z = gamePadStateP1.ThumbSticks.Left.Y;
29
30	base.Update(gameTime);
31	}
32	//…
33	void DrawGameObject(GameObject gameobject)
34	{
35	foreach (ModelMesh mesh in gameobject.model.Meshes)
36	{
37	foreach (BasicEffect effect in mesh.Effects)
38	{
39	effect.EnableDefaultLighting();
40	effect.PreferPerPixelLighting = true;
41
42	effect.World =
43	Matrix.CreateFromYawPitchRoll(
44	gameobject.rotation.Y,
45	gameobject.rotation.X,
46	gameobject.rotation.Z) *
47
48	Matrix.CreateScale(gameobject.scale) *
49	Matrix.CreateTranslation(gameobject.position);
50
51	effect.Projection = cameraProjectionMatrix;
52	effect.View = cameraViewMatrix;
53	}
54	gameobject.position += gameobject.velocity;
55	mesh.Draw();
56	}
57	}
58	//…
59

I've started my own game project based on the 3D tutorial. I didn't
complete the tutorial but I had the basics of what I needed for my
game. But, there's one issue that has stopped me from progressing. The
rotation doesn't work right. The X rotation works fine, but when trying
to rotate Y and Z, they act like one another. Example: trying to tilt
the level forward using the Y axis spins it like a record. Trying to
tilt it using the Z axis also spins like a record, but in the opposite
direction.

If you look at line 28, there's a rotation on the Z axis, but I also tried the Y axis and neither achieves the affect I'm looking for.

Here's the full project: http://www.thestoryofbob.com/content/RotateIssue.zip

If it matters, I modeled in freeware program Blender and I used XNA 3.0 CTP.

Any help would be greatly appreciated.

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