A graphics processing apparatus and method of graphics processing is disclosed. Obscuration identification circuitry is configured to receive graphics fragments from rasterization circuitry and to identify an obscuration condition if a received graphics fragment, in combination with at least one previously received graphics fragment, will obscure at least one further previously received graphics fragment. Process killing circuitry is configured to prevent further processing occurring in the graphics processing apparatus with respect to the at least one further previously received graphics fragment if the obscuration identification circuitry identifies the obscuration condition.