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When setting a particle system to be active after deactivating the remaining particles still floating in the air from earlier will flicker. This is harder to reproduce when smooth frame rate is enabled. The flicker is more consistent if the camera is closer to the particle system and the frame rate is fixed.
The Particle System will have a slight flicker once reactivated this is noticeable on the particles left behind still floating in the air.
There is no flicker
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