jagged shadows object population

Started by radix, November 29, 2016, 12:44:56 AM

Previous topic - Next topic

radix

Hi everyone, I'm having trouble with shadows cast by obj populations in tg4.

So I have a population which I'm using to scatter rock objects. When the population is at 0 for both the area rotation and area centre (the default location) the shadows cast by the objects appear as I would expect.

However, when I move the population further away from the default 0,0,0 population location, the more jagged and detached the shadows become. If I go far away enough, the population shadows disappear entirely.

I thought perhaps this was because the 'Area rotation' wasn't perfectly parallel to the ground, but even when I manually rotated the population bounding box flat to the surface, the issue remained. I also thought perhaps the rocks weren't perfectly flat on the terrain, but they are, even though they may look like they're floating, like in the "REF B" image.  (REF A is with the population at 000, REF B and C have been moved).

Am I missing something obvious, or is this a bug? I'm on a mac. I was having that obj shadow related problem earlier (http://www.planetside.co.uk/forums/index.php/topic,22424.0.html), so perhaps this is related?

Dune

Must be a (Mac-related) bug. This is what happens if I pop some rocks at the equator. Only GISD is a bit weird.

radix

Thanks for testing, yeah seems to be just a mac issue :/

Oshyan

Very strange. Unfortunately our Mac developer is still offline after the New Zealand earthquake, but we'll try to look into this ASAP.

- Oshyan

Oshyan

After looking at this issue a bit more, we don't think it's Mac-specific, although it may for some reason be worse on the Mac. It has to do with limited precision of coordinate systems in the renderer when dealing with very large distances. The coordinate system basically loses precision when far away from 0,0,0 (coordinate origin). These and other related issues are especially prominent when you are close to the surface *and* far away from the origin, so it's not advisable to do that if you can avoid it. But this specific shadow problem seems worse than it should be, so we'll look into how we might be able to mitigate it.

- Oshyan

radix

Thanks Oshyan, hopefully this won't be too tricky a fix