Well,
Try to imagine river that flows over the hill and leaf is in the water. Hill is object,
river is texture (which is not important I'm just changing UV coordinates with TextureMatrix to get moving effect)
and leaf is also an object.
So leaf follows flow of the river.
Of course you can assume that Camera is fixed.
I'm sending you embarrassing picture to get the idea, and hope it's enough.
Thank you kindly for what you have done and still doing.
Try to imagine river that flows over the hill and leaf is in the water. Hill is object,
river is texture (which is not important I'm just changing UV coordinates with TextureMatrix to get moving effect)
and leaf is also an object.
So leaf follows flow of the river.
Of course you can assume that Camera is fixed.
I'm sending you embarrassing picture to get the idea, and hope it's enough.
Thank you kindly for what you have done and still doing.