Adding special effects such as bump maps to water material is a great way to add realism because bump maps add depth and detail to materials. In the case of this model, the bump maps add the ripples on top of the water we are all use to seeing on any body of water like a lake or a pool.

Also, if your renderer has special water effects such a bump maps, then they can be used to make realistic water which will reflect buildings, sky and other background objects realistically.

• Distorted reflections to represent water ripples.
• More Realistic highlights from reflection of light.
• Realistic transparency caused by ripples and reflection of light.

Image of a pool with no bump map applied.