Creating an Interactive 3D world with C# and DirectX

3. Set Camera

In the Form1 class, you declare and initialize some variables to set up the camera position and then move it through the scene as follows:

//Declaring variables for camera movement
float sngPositionX;
float sngPositionY;
float sngPositionZ;
float snglookatX;
float snglookatY;
float snglookatZ;
float sngAngleX;
float sngAngleY;

Now, coming back to the Form1_Load event, you set the position of the camera:

//Set the view to perspective
TVScene.SetViewFrustum(45.0f,1000.0f);

The arguments for the above function are:

sAngleFOV	Angle in degrees representing the FOV (Field of vision) of the view.
sFarPlane	Maximum distance of vision. Everything after this imaginary far plane will be not rendered.

//set our camera location and lookat point, etc.
sngPositionX = 0.0f;
sngPositionY = 0.3f;
sngPositionZ = 0.0f;
snglookatX   = 0.0f;
snglookatY   = 0.0f;
snglookatZ   = 0.0f;
sngAngleY    = -1.57f;

With SetCamera, you can't define a camera with a totally vertical orientation. To do this, you have to use the RotateX method or use special matrices. SetCamera also can be used with a trigonometry equation to get a fully working camera system.

TVScene.SetCamera(xpos As Single, ypos As Single,
                  zpos As Single, xlookat As Single,
                  ylookat As Single, zlookat As Single)

xpos	X coordinate of the camera position
ypos	Y coordinate of the camera position (altitude)
zpos	Z coordinate of the camera position
xlookat	X coordinate of the camera look at point
ylookat	Y coordinate of the camera look at point (altitude)
zlookat	Z coordinate of the camera look at point

The behaviour is undefined if you use Position = LookAtPoint values.

//The camera is initially set to the origin (0, 0, 0) values
TVScene.SetCamera(sngPositionX, sngPositionY, ngPositionZ, snglookatX,
                  snglookatY, snglookatZ);

Figure 9: Setting camera position and look at position