[2.0.03] Rendering Bug : Horizon cut-off at certain angles

[Doomroll]

Graphics Card: AMD Radeon R9 280X
Graphics Driver: 15.301.1801.1001
CPU: AMD FX-4170 Quad

This bug was seen on my previous R7 250 as well.

Line Horizon cuts off and the expanding horizon is rendered extremely dark at certain angles when also using upper/lower sector things in the same map. When looking directly at the horizon it renders fine, but standing directly next to the Line Horizon and turning to certain angles, the horizon cuts of and renders very very dark (virtually completely black). Example Video HERE

I have found the following solutions:

1) Removing any Upper/Lower Sector things (or simply not tagging them)
2) Setting Sector Light Mode to Software
3) Setting Fog Mode to Standard or Off

[Graf Zahl]

I can't debug a video. You'll have to send me the map to check it.

[Doomroll]

True Story. Sorry about that.

HERE IT IS

Forgive the missing textures on MAP02...I didn't include the resources for it. Shouldn't matter, anyway, because the issue is most notable on MAP01 in the very northwest corner by the "Beach".

[Graf Zahl]

fixed. This was caused by losing the viewpoint in the shader which caused incorrect fog distance calculation. Believe it or not, the house's roof was the culprit...

[Doomroll]

That's awesome to hear! I knew it had something to do with the roof since it stopped happening when I removed the sector portal, I just didn't know how. But you're saying it had to do with the geometry inside the upper sector, not just rendering the sector?

I am super fascinated by this sort of thing, but I only understand about 1% of it. In any case, thanks so much for all your work on this port!

[Graf Zahl]

It had to do with the presence of the portal.
Here's what happened:

- main map was rendered (with player as camera)
- portal was rendered (with repositioned camera)
- horizon was rendered (still with the roof's camera viewpoint)

But the horizon needs to be rendererd with the player as camera viewpoint so that the fog distance can be calculated correctly.

[Doomroll]

Well, hell, that's actually really simple to understand. As usual, I was overthinking it.

I just tested it using the latest build and it's rendering beautifully. Again, thanks for that...and thanks for taking the time to explain it, too!