How to add transparency on edge of object?

[0alisa]

I have a model of a lake, which I place onto a flat grass object.

Currently, the edge of the lake is very noticeable.

Attached is a picture of the lake model

I cannot use shaders or procedural textures, as the model is used for an opengl game.

What I would like - is to be able to create an outer set of polygons around the lake, that I can assign a different surface. Then onto the outer polygon surfaces, apply a new water image which the alpha channel varies to merge the water into the grass in a non-uniform manner.

Is this possible?

[lolly]

Originally Posted by 0alisa

Attached is a picture of the lake model

Nothing is attached