GZDoom on GL 3.x core profile

[Graf Zahl]

Clip planes should already be disabled on that hardware. This cannot be done via CVar, it requires alteration of the shader so that the variables are never accessed.
No idea why it goes entirely black...

You can try setting gl_plane_reflection to 0 to disable the feature entirely and see what happens.

[Rachael]

That stopped the screen from going black at that spot.

[Rachael]

Okay - (sorry for bump/double post but I figured this information might be important)

Playing Sapphire (here's a direct link for anyone else who wants to test it), I did notice on my NVidia 860M, that facing southeast at point -2141, 2141 causes a black flicker to appear. You have to move around a bit in order to get it. Turn plane reflections off, and it goes away.

EDIT: More info - look right down into one (what would otherwise create an "infinite mirrors" effect) causes the screen to go completely black.

[Graf Zahl]

Damnit! I just played that map three weeks ago and it was all fine. I wonder what happened here.

[Rachael]

Also at -2400 6300 there is a huge HOM in the window looking outside. It seems like that is taking advantage of a quirk in ancient versions of GZDoom where the sky would fill the buffer completely if any point of it was visible - so that could be a mapping thing. I remember back in those days I did a similar trick in Skulltag because it rendered faster than using Line_Horizon.

[Graf Zahl]

Fixed the black screen. The portal code used a 2D drawing function which is no longer allowed. I just missed that one when making the changes.

[Graf Zahl]

About the HOM, I cannot reproduce this. The sky renders fine in all render paths.

[Rachael]

This is on my NVidia 860M. The HOM appears as white now because I set r_clearbuffer 2 in my autoexec. I can see the top and the bottom of the sector, and the sky shows through, but the entire white area is not drawn at all. It is affected by changes to r_clearbuffer. The same thing happens on Intel HD4600. This is pretty ancient - it took digging up a really old version (~2005 or so) not to see this happen. The HOM is present in ZDoom, also.

[Graf Zahl]

In ZDoom this creates HOM for me, too, which means that this really is a mapping bug.

In GZDoom it only happens if gl_no_skyclear is set to 1. This forces all skies to use the stencil method. If this is 0, the first sky will be drawn below the scene without a stencil so that the HOM will never show.

[Rachael]

Ah, that fixed it. I think I will just keep it at 0 since a lot of mapping that I've done uses this "bug" as well.

[Graf Zahl]

Map bug, not "bug". This is undefined behavior, so if you can you should fix it.

[Rachael]

I don't have write access to said maps anymore - and I think the project to which they belonged is long dead now.

[Gez]

Okay - (sorry for bump/double post but I figured this information might be important)

Playing Sapphire (here's a direct link for anyone else who wants to test it), I did notice on my NVidia 860M, that facing southeast at point -2141, 2141 causes a black flicker to appear. You have to move around a bit in order to get it. Turn plane reflections off, and it goes away.

EDIT: More info - look right down into one (what would otherwise create an "infinite mirrors" effect) causes the screen to go completely black.

It might be the same thing: there's a point in Torm's Wolfendoom BOA mod where mirrors on the walls are facing each other. (In the St. Quentin Paris map, C1M5.) Screen goes black when that happens. Turning away restores normal rendering.

[Graf Zahl]

It is the same thing.

[Rachael]

Alright Graf: You're gonna probably find this weird - or maybe it will all just make sense to you - but, either way - when you fixed the plane reflection bug, it fixed it on AMD drivers, too. Clipping planes are still broken as before but otherwise - everything's just dandy. No black screen. Having to use a self-compiled build, at the moment now to test this, rather than the official devbuilds, since they seem to be falling behind. Singular reflective floors are working great, now, on my AMD.

But that makes me wonder if it was the same problem to start with. I am doubting that clipping planes had anything to do with the black screen, before. It could have just been my sudden warp to that specific position where the problem occurred, and clipping planes simply made the other problem you fixed less visible on the drivers that supported them - but more visible on the drivers they were broken on.