message: don't set sun parameters if we didn't have SH
  The parameters would turn out as NaN.
  We might need a better API for this, but it's
  never okay to set NaN values.
diff: @@ -384,12 +384,14 @@ void SimpleViewer::setIndirectLight(filament::IndirectLight* ibl,
  if (ibl) {
  float3 d = filament::IndirectLight::getDirectionEstimate(sh3);
  float4 c = filament::IndirectLight::getColorEstimate(sh3, d);
  + if (!std::isnan(d.x * d.y * d.z)) {
  mSettings.lighting.sunlightDirection = d;
  mSettings.lighting.sunlightColor = c.rgb;
  mSettings.lighting.sunlightIntensity = c[3] * ibl->getIntensity();
  updateIndirectLight();
  }
  }
  +}
  void SimpleViewer::updateIndirectLight() {
  using namespace filament::math;
  