void FixedUpdate()
 {
     if (spawnerSystem == null)
     {
         spawnerSystem = World.DefaultGameObjectInjectionWorld.GetOrCreateSystem <FixedRateSpawnerSystem>();
     }
     Time.fixedDeltaTime  = fixedTimestepSlider.value;
     sliderLabelText.text = $"Fixed Timestep: {fixedTimestepSlider.value*1000} ms";
     spawnerSystem.Update();
 }
 private void FixedUpdate()
 {
     if (spawnerSystem == null)
     {
         spawnerSystem = World.Active.GetOrCreateSystem <FixedRateSpawnerSystem>();
     }
     Time.fixedDeltaTime  = fixedTimestepSlider.value;
     sliderLabelText.text = $"Fixed Timestep: {fixedTimestepSlider.value*1000} ms";
     spawnerSystem.Update();
 }