Hi Devs,
I found a solution for a bug and wan´t to share it so you won´t waste your time like i did…
If you are using the “Sample RVT” Node in Niagara, make sure there is at least one actor with a material in the level which is reading the same RVT file.
Otherwise the RVT Drawing for this file is in something like a “Standby” mode.
It seems like unreal doesn´t draw the RVT when you only use it in Niagara “Sample RVT” Node.
I align my particles to the ground with RVT World Height from the landscape material.
I experienced my particles walking through little hills and hover aboth the surface.
The RVT will have a very bad solution or just a precalculated version or something when it is not used by a material in the world.
After I added an actor with a material which is reading from the RVT my particles aligned perfect with the ground.
Regards Nik 