Allow a method to reverse ParticleEmitter's direction

At the moment it’s not possible to get a particle effect to appear at an outer-most point, sending particles towards an origin point. (Reverse particle direction)

I had an idea involving a way to make the speed property of particles negative. What this would do is simply make the particle’s position the same as if it were at the end of its lifetime at a positive speed (so in a way, pre-calculate the end position of the particle) and then move it towards the emitter’s origin.

This is a fairly simple idea in terms of explanation but it would make room for quite a few effects that developers can use. Many effects people would love to make rely on this out->in direction, so I think the use cases are more than present enough for a demand on this feature.

What do you all think?


Really good idea, even though I (and others I know) have thought of having reverse-particles would be cool, we never thought to make a feature request.

Currently the only way you can do anything like this is by decreasing size on large, stationary particles, which isn’t very cool.


Yes I hope this happens because with the current way ParticleEmitters work,
you can make Explosions (In->Out) but not Implosions (Out->In).

There is no current way to do that with just one ParticleEmitter.

You would have to make like a ring of tiny invisible parts with a ParticleEmitter in each one, aligning the front face of each part towards a center point, and having the emitters go from big to small as it reaches the center point to give it that Black Hole effect.

Edit: Also this would make it possible to do reverse time effects. Say you are doing a cutscene and a car blows up. You use a particle emitter to do the explosion while parts fly everywhere. But then the cutscene slows down and then stops, part movement is frozen still. Then time reverses and everything goes back to the car and the car fixes itself as if the explosion never happened. This is possible but with one exception, the ParticleEmitter wouldn’t stop, it will keep its exploding out effect during the time reversal. So this is one use case where a reverse property or something would come in handy.


Excuse me for the necrobump, but if this isn’t already achievable, then I feel I should bring this topic back up again. I’m sure people could find many use cases for reverse particles, like a black hole and having gusts go into it or something. I can’t explain my stance in depth right now, but what I can say is that I’d like this.


Currently this has a low chance of being implemented because there are not concrete use cases. It would help if you give specific examples and post screenshots from games/movies that have effects you’d like to make.

I would love to see an expansion of the particle system. It’s very restrictive compared to other game engines. Even by simply allowing particles to be pulled instead of pushed, tons of effects become far easier and less intensive to achieve.

For example, this inwards portal effect requires 63 ParticleEmitters to make all of the particles converge. With reversible ParticleEmitters this would require only 1.

Common effects with moving water or wind involve sucking rather than blowing (ie. Eely in Super Mario Sunshine). While Eely is mostly a stationary character, to achieve an inwards wind or water effect on a moving object or character, multiple ParticleEmitters are required and all of their positions must be maintained relative to the moving entity. This is tedious to set up and unreasonably intensive for more complex effects as a large amount of ParticleEmitters are required to reduce the amount of obvious emission points.

7 ParticleEmitters were needed to achieve this effect on only the single dimension shown in this video, and you can clearly see where the particles are originating from which is unattractive.

It’s also common to see charge attacks or spells that directly target things accumulate energy or power by drawing particles inwards towards the weapon or target. Here are some isolated examples of this found on YouTube.

(source: game vfx demo - YouTube, game vfx demo - YouTube, game vfx demo - YouTube).

I have wanted to do charge attacks with inwardly drawn “charging” particles, but creating attractive effects is a pain because I have to resort to hacks like rapidly shrinking textures. This trick is also difficult to work with without programming due to restrictions with the visual NumberSequence selector (value maxes out at 10), which makes larger effects difficult to fine-tune.