public Matrix4f getProjectionMatrix() {
        if (overrideProjection) {
            return projectionMatrixOverride;
        }

        return projectionMatrix;
    }
Provides access to the projection matrix.
@return the projection matrix of the camera.

<p>The view projection matrix  transforms eye space into clip space.
This matrix is usually defined by the viewport and perspective settings
of the camera.
jme3-core/src/main/java/com/jme3/renderer/Camera.java