ParticleEmitters have a biased particle distribution on their X axis, despite having a SpreadAngle of (180, 180)
Reproduction Steps
To reproduce, insert a Part into the workspace, and insert an Attachment with a ParticleEmitter inside of it. Set its SpreadAngle to (180, 180). To best visualize the bug, set its Rate to 1000, its Drag to 3, and its speed to (5, 40).
The following photos demonstrate this behavior. They are both taken from the top perspective.
With ParticleEmitter:Emit(10000):
With ParticleEmitter.Enabled (with rate of 1000):
Expected behavior
ParticleEmitters should have an equal distribution on all axes
Actual behavior
ParticleEmitters have a biased distribution on the X axis
Workaround
Use Sphere
for the ParticleEmitter’s Shape property. This doesn’t work for particles under attachments.