viewProj
The viewProj matrix, often referred to as the view–projection matrix, is a fundamental construct in 3D computer graphics. It represents the combination of a camera's view transformation and the projection transformation that converts 3D world coordinates into 2D screen coordinates. By multiplying a vertex’s position first by the view matrix—accounting for camera position, orientation, and target—and then by the projection matrix—determining perspective or orthographic projection—the viewProj matrix condenses both steps into a single matrix operation. This consolidation reduces computational load in shaders and improves pipeline efficiency.
In practice, the view matrix is derived from the camera’s eye position, look-at point, and up vector,