Vector3[] face = i.next();
//compute normal
Vector3 n =face[1].sub(face[0]).cross(face[2].sub(face[1])).normalize();
for ( Vector3 v: face) {
gl.glNormal3d(n.x, n.y, n.z);
//gl.glTexCoord2f(1.0f, 1.0f);
//gl.glColor3d(v.a1, v.a2, v.a3);
gl.glVertex3d(v.x, v.y, v.z);
gl.glTexCoord2f(0.0f, 1.0f);
}