Particles – the default ones (smoke/fire) and the ones emitted by particle emitters – don’t render correctly when they are emitted in front of/on top of semi-transparent parts.
Instead of rendering on top of the parts like they should, the particles render behind them. This bug happens in studio and in game.
Here’s a repro: particleemitter_bug.rbxl (16.2 KB)
In the repro, there are three parts: a background part with 0.3 transparency, a part that has a particle emitter, and a transparent part that emits the default fire. The parts with particles are placed above the background part. From the side view, you can see the particles just fine. However, from the top view, the particles are hidden behind the transparent part.
Side view:
Top view:
Bottom view:
GIF:
