Camera Control in DirectX

Croow gave the way that DirectX doesn't like very much, but it's fun to see. If you play around alot, you can cause movement that's quite wild.

Here's the way using Matrices (which tends to be much nicer).

First you must understand what we're doing here. Here is how the DirectX view matrix is set up. (I think)
Right, Look and Up are axis definitions for orientation (x=Right, y=Up , and z=Look)

Right.x     Look.x     Up.x         0
Right.y     Look.y     Up.y         0
Right.z     Look.z     Up.z         0
Position.x Position.y Position.z 1

You can access these members of your view matrix by using matrix coordinates (  row , column )
In C++ access D3DXMATRIX data members by putting an underscore ( '_' ), the row number, then column number. (example: matrix1._14 is row 1 column 4, which would be zero in a view matrix) .

Now to rotate.

Create 3 variables (float), one for each axis. These will hold the current rotation angles.
Create 3 D3DXVECTOR3 variables. These will be your Right, Up, and Look vectors.
Make sure you initialize them with data such as Right= 1,0,0 , Up = 0,1,0 , Look = 0,0,1 (which are the default values).
Next, you need to make sure these vectors are all perpendicular to eachother. Do this with the following code.

D3DXVec3Normalize(&Look, &Look);
D3DXVec3Cross(&Right, &Up, &Look);
//this function is the Cross product, which creates a perpendicular vector to two vectors (this is also how you calculate polygon normals - except you use normaized vectors formed by edges)
D3DXVec3Normalize(&Right, &Right);
D3DXVec3Cross(&Up, &Look, &Right);
D3DXVec3Normalize(&Up, &Up);

Notice that this makes all the vectors perpendicular to the Look vector. You could make them all perpedicular to another one of the axis if you wish.
Now, create rotation matrices for each axis using D3DXMatrixRotationAxis. Example code:

D3DXMatrixRotationAxis(&mat_X_Rot, &Right, x_angle);
D3DXMatrixRotationAxis(&mat_Y_Rot, &Up, y_angle);
D3DXMatrixRotationAxis(&mat_Z_Rot, &Look, z_angle);

Now transform the vectors by the matrices.

D3DXVec3TransformCoord(&Look, &Look, &mat_Y_Rot);
D3DXVec3TransformCoord(&Right, &Right, &mat_Y_Rot);

D3DXVec3TransformCoord(&Look, &Look, &mat_X_Rot);
D3DXVec3TransformCoord(&Up, &Up, &mat_X_Rot);

D3DXVec3TransformCoord(&Right, &Right, &mat_Z_Rot);
D3DXVec3TransformCoord(&Up, &Up, &mat_Z_Rot);

In that code you are essentially just rotating one axis about another.
Now, using what I've told you earlier, YOU fill in your view matrix.
By the way, don't forget to create it with D3DXMatrixLookAtLH.

This ONLY covers orientation. I didn't mention much else that you need to know.
(like that if you have position involved here, that you need to make _41, _42, and _43 = to
D3DXVec3Dot(&Position, &(the vector in the above rows of this column (ex: row 1's = Right ) )  )  )

There is also a much simpler way to do this using quaternions, but quaternions, to me, are one of those things that I use, but don't understand.

RageDBL