Just set up a quick BP that spawns a Niagara System, but it is not casting shadows… I see the Cast Shadow Toggle is disabled by default and you can turn that on once the system is in the world. But because I am spawning it through the BP I don’t seem to have access to that option… Wondering if the systems need to be embedded as a component in the BP…
“CPU Sprites in UE4 can cast shadows on the environment… However, it should be noted that shadow casting such as this does not work for GPU particles.”
Do you know if you’re using GPU or CPU particles?
If you drop the emitter/system in the level (as opposed to spawning it) are you seeing shadows?
Yes, I am using CPU particles and if I drag and drop the Niagara System in the level and then select Cast Shadow in the attribute tab then it does work. But because that toggle is disabled by default, when I spawn the system through a BP I don’t know how to find that “Cast Shadow” button to be turn on.
Ok, try selecting the Niagara component in the components panel inside of your BP, then changing the setting there should spawn all instances of the BP with the setting on.
OR If for some reason that does not work, you could try to explicitly enable it. (Firing that logic on BeginPlay could work too, but the construction script happens just a little bit sooner)
For the record - I tried this with the ‘MeshRotation_System’ in the content examples (Incase you are using something different than a mesh renderer and still having issues)
Tangentially related: If you select a variable in your BP you can enable ‘expose on spawn’ and that will give you those inputs on your ‘spawn actor’ node.