Function erode

terrain.js:384–392

(h, amount)

}

function erode(h, amount) {
    var er = erosionRate(h);
    var newh = zero(h.mesh);
    var maxr = d3.max(er);
    for (var i = 0; i < h.length; i++) {
        newh[i] = h[i] - amount * (er[i] / maxr);
    }
    return newh;
}

function doErosion(h, amount, n) {
    n = n || 1;