hwCamera - create a virtual camera for viewing a scene
| Pos | 3F | The position of the camera |
| Dir | 3F | The direction the camera is pointing |
| Up | 3F | The direction which is considered "up" |
| Field | 1F | The field of view, in degrees |
| Aspect | 1F | Aspect ratio of the viewport |
| Perspective | 1B | True for perspective projection, false for orthographic projection |
| Planes | 2F | The front and back clipping planes, defined as distances along the Dir vector from the Pos point. |
| Jitter | 2F | X/Y microjitter, for antialiasing |
| Skew | 2F | X/Y skew, for skewed cameras |
| Mirror | 1B | True iff the image should be mirrored in X |
| Pos | {0,0,-1.4} |
| Dir | {0,0,1} |
| Up | {0,1,0} |
| Field | 90 |
| Aspect | 1.0 |
| Perspective | HW_TRUE |
| Planes | {0.4, 2.4} |
| Jitter | {0,0} |
| Skew | {0,0} |
| Mirror | HW_FALSE |
The hwCamera class provides a mechanism for specifying a virtual camera through which a scene may be viewed. The camera is located at a particular point in 3-dimensional space, and points in a certain direction. The camera may be rotated around this direction by modifying the Up vector. The Planes describe the volume being examined by the camera; objects in front of the first plane or behind the second are not visible. The Planes additionally define the depth range used for depth buffering; for best visual results, you should try to set the Planes value to just encompass all of the interesting objects in the view.
By default, the view is an orthographic projection of the unit cube about the origin. In order to establish a camera object as the current viewing camera, merely execute its draw method. Note that the camera MUST be drawn before any lights or objects are drawn; if this rule is not followed, visual results are undefined. Note also that only the first camera drawn after an hwUpdate has any effect; subsequent camera draws are ignored. This allows, for example, an interactive camera to take precedence over an animated camera.
/* Create a perspective view of the origin from far away, but
* with a fairly narrow field-of-view
*/
hwObject
camera;
camera = hwCamera->create( hwCamera );
HW_MODIFY_3F( camera, hwStrPos, 0, 0, 300 );
HW_MODIFY_1F( camera, hwStrField, 30 );
HW_MODIFY_2F( camera, hwStrPlanes, 1.0, 600.0 );
HW_MODIFY_1B( camera, hwStrPerspective, HW_TRUE );
camera->draw( camera );
# A perspective view of the origin from far away
hwCamera {
Pos = {0,0,300}
Field = 30
Planes = {1,600}
Perspective = True
}