var texture = THREE.ImageUtils.loadTexture(basePath + '/images/textures/dt.jpg', new         THREE.UVMapping());
texture.wrapT = THREE.RepeatWrapping;
texture.wrapS = THREE.RepeatWrapping;
texture.repeat.set(1,1);
stairmaterials[0] = new THREE.MeshBasicMaterial(
    {
        side: THREE.DoubleSide,
        map: texture
    });

geom.computeBoundingBox();

var max = geom.boundingBox.max;
var min = geom.boundingBox.min;

var offset = new THREE.Vector2(0 - min.x, 0 - min.z);
var range = new THREE.Vector2(max.x - min.x, max.z - min.z);

geom.faceVertexUvs[0] = [];
var faces = geom.faces;

for (i = 0; i < geom.faces.length; i++) {

    var v1 = geom.vertices[faces[i].a];
    var v2 = geom.vertices[faces[i].b];
    var v3 = geom.vertices[faces[i].c];

    geom.faceVertexUvs[0].push([
        new THREE.Vector2(( v1.x + offset.x ) / range.x, ( v1.z + offset.z ) / range.z),
        new THREE.Vector2(( v2.x + offset.x ) / range.x, ( v2.z + offset.z ) / range.z),
        new THREE.Vector2(( v3.x + offset.x ) / range.x, ( v3.z + offset.z ) / range.z)
    ]);

}

geom.uvsNeedUpdate = true;