////  px_rgba.fs//  examples/tests/skybox////  Created by Zach Pomerantz on 3/10/2016//  Copyright 2016 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html  vec3 getSkyboxColor() {    float red = (cos(iGlobalTime) + 1) / 2;    vec3 color = vec3(red, 1.0, 1.0);     vec3 coord = normalize(_normal);    vec3 texel = texture(cubeMap, coord).rgb;    color *= texel;     return color;}