Working with the View Matrix
The view matrix takes the world space coordinates produced by the modelview matrix and transforms them into the camera or eye space. The eye space assumes the origin of this space to be at the position of the camera or viewer’s eye. As we saw in Chapter 4, Graphics and Game Engine Components, the eye space can either be a frustum (a pyramid with the top cut off for perspective views) or orthogonal (a rectangular prism for parallel views). The view matrix can take translation and rotations like the modelview matrix, but instead of transforming individual objects, it transforms everything in the world. That’s because it’s basically the equivalent of moving a camera around in the world, and then determining what the world will look like through that camera.
Unlike the modelview matrix, which can be loaded after an OpenGL call to glGetDoublev( GL_MODELVIEW_MATRIX)
, the view matrix sets a special matrix mode. The view matrix is multiplied...