Question smooth emit over time/distance using velocity only

Hello.
With fast movement, spawning can appear to be "choppy". This is in part due to the fact there's "too much movement" between two frames. So increasing the spawnRate won't really help.
What can be done instead is to store the "Previous Position" (previous frame position) and interpolate between the previous and current frame.

In the Setup that I'm sharing, the "Lead particles" system is storing the "Current Position" in an attribute (oldPosition). This is done before the velocity integration (Moving position due to velocity) by the Update Context.


To spawn particles, I'm using a "Trigger Event Always" that will fire every frame.

If I get the "Source position" of the lead particle and use it directly to set the position of the Child particles, as said earlier, we can see a stepping effect.






So, as we have stored the Position before velocity integration in the "oldPosition" attribute, we can interpolate between the "Source oldPosition" and "Source Position". And to interpolate and random values between 0-1 will do the trick:


Instead of using a Random, you can use the SpawnIndex attribute. As we're using a Trigger Event Always, all particles are spawn on the same frame in a burst fashion. This mean that each frame, this index will be between 0- and the Count number set in the trigger event.

With this in mind, we can use it to interpolate our position.

 

Hope this post will help you.I'm including a small package so that you can take a look.
Have a nice day.

 

No worries. Hope it helped. Have a great day.