message: webgl1 compat
diff: @@ -12,7 +12,9 @@ export const apply_light_color = `
  if (uBumpFrequency > 0.0 && uBumpAmplitude > 0.0) {
  vec3 bumpNormal = perturbNormal(-vViewPosition, normal, fbm(vModelPosition * uBumpFrequency), (uBumpAmplitude * bumpiness) / uBumpFrequency);
  #ifdef enabledFragDepth
  - if (!any(isNaN(bumpNormal))) normal = bumpNormal;
  + if (!isNaN(bumpNormal.x) && !isNaN(bumpNormal.y) && !isNaN(bumpNormal.z)) {
  + normal = bumpNormal;
  + }
  #else
  normal = bumpNormal;
  #endif
  