I’m Julien and this is my first post here!
Hope I’m in the right place for the issue I’m facing.
I’ve started learning UE4 in 2020 and I did overcome many difficulties thanks to wonderful resources available online, in this forum and other places.
Though, now is the time for me to reach out for help.
I’m working on an effect where particles are emitted from a video texture. Particles spawn on a rectangle surface, inherit from the color of the video texture corresponding to their position, and then travel at constant speed away from the rectangle.
My problem is that the effect doesn’t work until I open the Niagara System. It doesn’t seem to compile until then.
All works fine after I open the Niagara System, it works when playing in preview mode, but it doesn’t work again in the packaged game.
I am certain that it comes from the “sample texture” node in the Niagara emitter, because if I duplicate the system and delete the node, the particles are emitted (the white particles in attached pictures).
It seems that the Niagara system has trouble sampling the video texture.
Any idea on how to fix this issue?
I guess I should somehow force the Niagara system to compile via blueprint, but I don’t know enough about the engine to do so.
I hope my explanations are clear enough, tell me if it isn’t.
Thanks very much,
Happy end of the year.
Engine version: 4.25.4
Also, the video is stored in Content/Movies, as I’ve red it should be.
Hi, I would like to keep this thread alive as I encountered the same problem when I packaged the game for android.
I selected ETC2 option for packaging and tested it with my phone. An explosion animation done with Niagara system didn’t spawn or it just didn’t show anything visually.
When I tested on mobile preview mode on editor, Niagara effects worked, but still required couple of seconds to compile the shader. It didn’t show the effect fully in the first couple of trigger events. It still requires some time to wait after the first trigger event to show the full animation.
I’m also having this problem and it looks like it’s an engine bug. I have a Niagara system with a single looping particle that only begins working in game after I open up the effect.
After I open up the effect it works the entire time the editor is open, but when I close the editor and open it back up again, the effect stops working again. The effect does not work in packaged executables either.
If I make a package AFTER opening the effect to get it working again, then the built package fails to start when I run it and I get a LowLevelFatalError from line 1161 in AsyncLoading2.cpp stating “Bad export index”.
This is a complete wild guess, but you could try putting your whole Niagara folder in “additional asset directories to cook” just to make absolutely sure it cooks it. It should be right under the map list in packaging settings.
CHANGE THE LIFE OR LIFESPAN TO BE HONEST I CANT EVEN REMEMBER WHAT THEY CALL IT BECAUSE I JUST TYPE LIFE IN THE DETAILS PANEL TO SEARCH
THE LIFE CAN BE NON-ZERO TO INITIATE THE RESPAWN OF THE NIAGARA PARTICLE SYSTEM
WORK WITH THE LIFE, THAT’S THE ANSWER
AND YES, SOMETIMES IT NEEDS COMPILED BUT IF YOU BUILD WHILE IT WORKS AND THERE ARE NO VALIDITY ERRORS ALSO IF THE LIFE IS NOT ALREADY SET TO END THE PARTICLE EFFECT AT A CERTAIN TIME THEN WHATEVER IT HAS TO HAPPEN, YOU HAVE TO COMPILE THE EFFECTS, THEN MAKE SURE THEY ARE PLAYING PROPERLY
YEA.
SO.
CHANGE THE LIFE BECAUSE MINE NEVER JUST SPAWN. I HAVE TO TELL THEM TO LAST LIKE 10000 SECONDS.
Hey! I have same issue in 5.3. It happens for me when I’m using “Generate Collision Event” with world space emitter. I have fixed this issue when disabled “Bake Rapid Iteration Parameters” in “Performance” block in System parameters.
Happens for us every time we pull from our repo with certain Niagara Systems.
The issue seems to be related to user parameters not being updated, recompiling and saving fixes it.
Also 5.3 and none of the fixes mentioned here work
