So, I’ve been working with the Niagara fluids from the 5.0 content examples, and I’m noting that they don’t actually appear to be visible in Lumen reflections. This alone isn’t that strange, I figured something as complex as real-time fluid simulation might not talk to RT that well initally, but it gets stranger.
I tested every sim, but the confusing ones are the 2DGasSmokeFire_CameraFacing, and the 3DLiquidDamBreak, and they behave very differenty: the 2D camera-aligned fire sim isn’t visible in lumen or other reflections beyond screen-space, but the path-tracer not only picks it up, but realistically propagates emissive lighting in real time. Hardware RT can access the path-tracer, but unlike other Niagara particles, it isn’t visible in lumen reflections.
The 3D liquid sims are also strange: they’re not visible in lumen reflections (in 5.0, I’ve tested them in _main builds that support translucent reflections and they work great), but they’re an unlit black color in the path-tracer. I believe this has less to do with Niagara and RT and more with the SingleLayerWater material, but I truly don’t know.
Has anyone else experimented with these effects? Would love to hear more, I am blown away by how powerful (and expensive) they are.