Any ideas how to fix this?
The hdri comes in well under the horizon, set to full dome, doesn’t happen with a vray plane. It’s worse when using motion blur.
This is using a simulation grid with infinite ocean rendering turned on, subdivisions at 4.
Hi! @Neilg !
Did you solve the horizon glitch? We have exactly the same problem with version PhoenixFD 4.30.00. and Vray 5 hotfix 2. Tried to play with displacement, motion blur, horizon roughness but no luck. BTW it happens with a simple VRayPlane as well so maybe it’s not even related to phoenix.
This happens with any geometry and I am guessing it is a conflict with the scene boundary. So as far as I can see an infinite anything won’t work here, only something finite.
For example, with IPR running, I scaled up a circular plane object arbitrarily and at a fixed given point that line appears, like it hit the scene edge and didn’t know what to do.
Changing units doesn’t fix or alter it. Odd limitation for sure, unless there is a secret fix 
EDIT: I found out that it is the reflection glossiness…the cause of other issues too. Anything below 100 and there’ll be a line.
EDIT 2: I thought I remembered this problem…switch to blinn and it disappears Black horizon line and artifacts - Issues - Chaos Forum
Yeah, sorry - should have updated. switched to blinn, set glossy to 1.0, painting out the new fireflies in post.
this film is nearly done now, should be posting it soon!
Thing is, with blinn it’s possible to use glossiness, which is good.
Too late now of course 
I wish these sorts of things would be added to docs…would make things so much simpler if there was an updating list of them.
I’ll give it a try with blinn mode! Thanks!