Returns the 3D engine frame rate (Number of frames per second), depending of the specied 'Type'.
'Type' can be one of the following values:
#PB_Engine3D_Current : Current frame rate
#PB_Engine3D_Average : Average frame rate achieved since the engine is running
#PB_Engine3D_Maximum : Best frame rate achieved since the engine is running
#PB_Engine3D_Minimum : Worste frame rate achieved since the engine is running
#PB_Engine3D_Reset : Reset the frame rate statistiques (minimum, maximum and average)