Emission of the Particle System is not visible when the Particle System is manually simulated

2023.2.X

As Designed

This happens because the Parent GameObject is not part of the particle "Effect". The Effect is defined as being all GameObjects that contain a ParticleSystem Component. This means that you can get the preview working in a few ways: 1. As you say, select TrailTest instead 2. Select TrailTest, and, in the Scene View preview options that appear, change Simulate Layers to a layer that includes the particle effect. Now it will always be visible in the scene view 3. Add a ParticleSystem component to Orbiter, and turn off all its modules (Shape, Renderer)