I’ve created a wind effect for my grass that is bound to a moving noise pattern to give the sense of wind gust. But when use on my very large landscape, on certain zone of the map, the system bug and we have no more noise pattern but just “line”. Hard to describe, see the video attach. Any idea what can be the cause?
Look at the video closely.
It’s a blurry mess probably from something like Gsync or VSync or your current rendering setup TSAA or similar.
Additionally, it’s possible that with larger worlds and no world origin re-basing your math is completely wrong due to floating point errors.
It would depend on how close to 0,0,0 the issue starts to occur, but you would see more and more of it become a “line” due to the fact that all the math starts to be less and less precise.
Thanks for the reply
The blurry mess is due to windows screen capture potato quality, sorry.
What’s weird is that it’s not gradually becoming messy the further I’m from origin, but it’s a discrete moment as seen in the video (the view is standing on the frontier). And I say massive world but it’s around 64km * 64km not thousand of km. And doesn’t Large world coordinate remove the distance from origin problem (at least for scale like mine)?
No it doesent.
0.6f x 100.00f already gives you floating point errors.
The difference is that the error is miniscule and you wont really notice it on something like a blade of grass moving.
But as you drift away further, then the once miniscule error is more significant.
To the point it eventually becomes a problem.
Large world coordinates also dont have anything to do with the material pipeline. So even if they did work for gameplay (hint, they do not), it wouldnt change much if this is in fact a floating point driven issue.
You could try plugging some known math into one of the debugging nodes to see how bad a result you are getting…
Oh and even with that, its hily provable the issue is the engine applying your WPO to the mesh while the mesh is at that location.
Basically having trouble adding the local position to your math because of floating point precision (which is not really something you can test in the material).
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thanks. soooo I’m kind of f*** I guess, that would also explain some weird behavior like trees kind of jerk movement in the wind with the default simple wind or pivot painter of asset 
World Origin Shifting / Rebasing will probably address the issue nicely, but you likely have to drop back a version of the engine or 2 and use the regular landscape rather than the new system.
Though surely, the origin shifting works in the new engine too somehow…
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