I'm currently struggling with a very bizarre issue that happened in UE5 when using Houdini Niagara plugins to create crowds.
For context to understand the issue, I'll try to explain clearly to the best of my ability.
I did a crowd fx before in UE4 a while ago. Using the houdini niagara point cache workflow, which is houdini niagara plugins in UE4's niagara system. I'm using houdini's point cache in UE4's niagara system and a list of VAT static characters to be instance randomly by niagara onto the points position. The fx works and run normally in UE4 even when close & re-launched the project again. Ticking the "Auto-activate" on & off works & runs normally too. (preview images will be provided for visualization below)
image above showing UE4 niagara working normally upon reopening project & toggling auto activate param
image above shows the UE4 niagara details tab auto activation checked on
However, things are strangely different in UE5. I use the exact same workflow, using houdini niagara plguin for UE5, same setup in nigara system in UE5, using the same concept for setting up the crowd. Which is VAT static characters to be instance onto houdini point cache randomly by niagara system in UE5.
But, here lies the problem. Once the niagara system is placed in the scene, after closing the project and re-launching it again, the niagara crowd does not do what it is intended to do.
Example, I have a list of 10 VAT character to be randomly instance onto the provided point cache with 20 point count. But after closing the project & re-launching it again, niagara immediately instance all 10 character onto all 20 point at once.
You'd expect niagara to randomly pick & place any one character from the list to placed it on the points. A single point should have only a single character on it by default. This issue did not happen in UE4 but it happen in UE5. (preview images will be provided for visualization below)
image above shows UE5 niagara acting strangely upon reopening project & toggling auto activate param does nothing
image above shows the UE5 niagara details tab auto activation checked on
For the love of god, I can't seem to figure out why & how this is happening and I will greatly appreciate if there is a simple & straight forward solution to this. I'm not entirely sure if I am actually missing something here or did something fundamentally changed in how niagara works in UE5. Or is there something going wrong with houdini niagara plguin?
Because this was not an issue in UE4's houdini niagara crowd.
So far, the only solution I know is that I have to open / launch the niagara system window to force niagara to refresh then only it works. Imagine what if there are 5 to 10+ niagara system in the scene, this gets very tedious and frustrating to do this 1 by 1.
I really do hope someone can provide some guidance & very much appreciated!
Kind regards & cheers!
