Graphics processing systems

In a graphics processing system, when rendering plural views of the same scene (step 43), such as for stereoscopic rendering, the vertex shading operation is configured so that rather than executing the vertex shader program separately for each view that is being rendered, a single vertex shading program is executed once for all the views. The vertex shader program that is executed is configured to, for view-dependent operations, perform the respective operation separately for each view (step 48), so as to derive an appropriate vertex shaded output attribute value for each view, and is configured to, for vertex shading operations that are not dependent upon the view being rendered, perform those vertex shading operations only once for the set of views and to provide only a single vertex shaded output value for each vertex attribute in question for the set of views (step 49).