Coordinate transformation in pipelines

1.   As shown in the figure above , An object is first in a local coordinate system , after model Matrix transformation , Including rotation, translation, zoom and so on , In world coordinates .
2. adopt view The matrix is transformed into the observation space .view The matrix is actually a matrix that translates the camera T A matrix of coordinate changes R Synthetic .view Matrix requires camera position 、 Up vector 、 Three vectors of the target position .
3.   adopt projection Matrix transformation into clipping space . The above three steps are generally carried out in the vertex coordinate system .
4. By perspective Division , Convert to standardized equipment coordinates (Normalized Device Coordinate, NDC).
5. Change through the viewport , Convert to screen space .