Haha well i guess its great to see that professional games use the same technique.The trick is to make it not just rotate back and forth but to increase and decrease height a little bit. The awesome thing about the sine movement is you can configure the values so that they are slightly random. For example, instead of all the grass objects swaying left and right at the same time, you can change the period offset to be randomized by 100%, causing all the objects to sway in the same cycle but starting at different points. However, I might rename Period offset to 'phase' because I think phase is the physics term when referring to waves. Also yeah my grass is a bit crazy and fast, but if you tweak the values in the properties you can make it more subtle.