2.2 viewport conversion
1. converted from world space to camera space.
2. The camera 3 parameter definition (EYE, AT, UP) by the
3.EYE: camera position in world space; AT: the reference point in the scene the camera is directed (usually located in the middle of the scene position); UP: camera pointing upward vector (most of the time the y-axis)
4. configuration parameters using the view the view space coordinates (u, v, n):
The world space flag (0, e1, e2, e3 ); tag camera space (EYE, U, V, n-)
6. The converted world space to camera space: <1> is moved to the EYE 0, <2> a rotation operation, the two operations can be combined (u, v, n) is converted to (e1, e2, e3) is the view matrix
7. viewport matrix:
2.3 per-vertex lighting
1. Light will be calculated at each vertex.
The light source is defined in world space -> are now commonly used by lighting tile
visible region 3 becomes the scene view volume, the view volume can be regarded as an infinite pyramid. Contains four parameters (fovy, Aspect, n-, F) (after FIG complement)
4.ascept (aspect ratio viewing volume) = w / n; fovy: defines the visible region in the vertical direction; n: an origin and from the near clipping plane; f: distance from the origin to the far clipping plane
5. n and f are taken through the plane of the view frustum, the view frustum grasp the internal structure of the camera. In view of the vertebral body portion depending on the vertebral body before entering the test GPU--
6. The entry section view of a vertebral body before the trimming operation proceeds to clip space.
2.4.2 Projection Matrix
1. perspective projection: depending on the vertebral body by the rotary table is converted to a rectangular (matrix by the projection), the projection line starting from the original point shaped into the form of parallel lines transmit. Wherein: small near the far (distant objects is reduced, after a large distant objects may be too small and the projection near distance compared to the distance [from the center of projection (COP)] of)
2. projection matrix:
3. After the object is defined in the right-hand projection conversion clip space, the vertex processing stage can be regarded as the final step.