public void setIterations(int iterations) throws Exception {
        if (iterations <= 0) {
            throw new Exception(
                    "Number of iterations is not greater than zero");
        }
        this.iterations = iterations;
    }
Sets the number of times the fluid simulation should be iterated over
the heightmap. The more iterations, the fewer features (hills, etcetera)
the terrain will have, and the smoother it will be.

@param iterations
           the number of iterations to perform
@throws Exception
            if iterations is not greater than zero
jme3-terrain/src/main/java/com/jme3/terrain/heightmap/FluidSimHeightMap.java