Model rendering bug. 1.8 Linux

[eyceguy]

Hey all! Think I found a minor bug.
I recently had my hard drive that was holding my O/S die on me. (No worries, Myth2 was on another drive ). So I decided to try to ditch Windows one more time and do a solo Linux build.

Anywho. The bug I mentioned occurs when I load up a map, none of the map models render. I did some sleuthing and I found out that it only happens with I have 3D fog enabled. Also it only happens the first time I load a map eg If I load Willow Creek or another map, and then back out and load up the same map or another then the map models render. This happens both in full screen and windowed. And nothing jumps out at me in the log file.

Not a big issue to me since I can just go without 3D fog, in which case the models load and display properly from the get go.

Anyway some specs here if you need them:
Fedora 19, with Kernel 3.11.3-201.fc19.x86_64
nVidia gtx650, with current official drivers. 325.15
**edit** forgot my myth2 build: 427

If you have any more questions or need a screenie lemme know.

Thanks!

[Melekor]

Please post a copy of your myth_log.txt as well as a screenshot of the rendering bug.

[eyceguy]

myth2log

Code: Select all

2013-10-13 19:20:34  
Myth II Build 427 running under Linux ----------------------------------------------
Loading poweruser.txt... not found.
DEBUG: Updating monolithic tag cache:
	Initial count: 103
	Number removed: 0
	Number added: 0
	New count: 103
DEBUG: Adding 15 monolithic tags:
	small install
	medium install
	large install
	international small install
	international large install
	Patch 1.2
	Patch 1.3
	Patch 1.4
	Patch 1.5
	GateofStormsNet
	Patch 1.8 Interface
	Expanded Interface (LPL)
	Patch Templates
	Magma - Bungie Map Textures v1
	Magma - Detail Texture Megapack
Scanning for software devices...
	Found 1 to use
Scanning for OpenGL devices...
	Found 1 to use
	GeForce GTX 650/PCIe/SSE2 | NVIDIA Corporation | OpenGL 4.3
Initializing sound with OpenAL...
OpenAL: Loaded OpenAL library 'libopenal.so.1'.
OpenAL initialized successfully.
Warning: Failed to play cutscene '01.mov' using ffplay - make sure FFmpeg is installed.
Running OpenGL 4.3 at 1280 x 800 (VSync ON)
Starting mesh "Willow Creek"...
Using 1.8.0 gameplay...
OpenGL: Initialized with ErasePreviousFrame=0, MaxAnisotropy=8, MSAASamples=1, UseDepthTest=1, UseMipMaps=1, UseNPO2Textures=1, UseShaders=1, UpdateCMapChunked=1, UseCMapTiles=1, UseAppleClientStorage=0
Saving screenshot to screenshots/screenshot- 2013-10-13 19.20.59.bmp...
Quitting single player game...
Closing Myth.

and screenie
linky

[Idles]

Nice thorough bug report. That's quite a fun issue. This is currently being looked into--don't want anyone thinking their bug reports go into a black hole.

[Melekor]

The screenshot looks like models are being rendered with depth write disabled. You can see the model is actually being rendered, but it's covered up by the mesh everywhere except the hole at the windmill base.

I tried modifying the code to purposely disable depth write for models and here's what I got: http://www.projectmagma.net/%7Emelekor/ ... -write.jpg

looks identical.


I'm not sure how depth write is being disabled on the first run for you. I don't think 3D fog is related because willow creek does not use 3D fog and thus the 3D fog code is not active on willow creek. Can you confirm the interaction with fog? I wasn't able to reproduce the issue on my at all linux virtual machine which leads me to believe it's driver related.

[eyceguy]

*edit*
Okay. So apparently, I mislead even myself. This issue happens with 3d fog on or of (my bad sorry ). It seems to happen no matter the setting when using the OpenGL 4.3 renderer. But like I said before, its only the first map loaded. Subsequent loaded maps render just fine.

*edit numero zwei*
Just for sh!ts and giggles, I decided to run the windows exe under wine with the same settings to see if the error reproduced there as well, since both would be forced through the system's opengl/nvidia as both are 32bit programs (the native linux and the wine executable). This issue did not happen. I dunno if there is a difference, but the linux version is still at 427 vanilla whereas the windows binary is 427b.
Is it possible that some shared code got modified for the 427b release that may not have been applied to the linux version?

[Melekor]

427b was a windows specific fix for something completely unrelated to graphics/opengl. I have a theory that there might be a bug in our opengl setup code on linux, I am investigating this and will get back to you.

[Melekor]

Can you also see through terrain at certain angles, like in this screenshot (below)?

http://www.projectmagma.net/%7Emelekor/ ... buffer.jpg

[eyceguy]

Loaded up Stair of Grief, and the answer is yes I can see through the terrain there.

[Melekor]

Cool, that lends credence to my theory that the context is being created with no depth buffer on the first run.

I made a test build that should confirm the theory, if the issue doesn't happen with it: http://www.projectmagma.net/%7Emelekor/ ... pthdbg.zip . Can you give it a spin and let us know if it fixes the issue?

[eyceguy]

Although I have to leave for work soon, I did try a few levels and that seems to have removed the bug. I will do some more testing when I get home tonight.

Thanks!

[Melekor]

Sounds promising, let us know if you've confirmed the fix.

[eyceguy]

I'm quite confident that the issue has been resolved here. I haven't seen it appear.

Thanks for your work!

[Melekor]

Great, I'll make sure that gets into the next fix build then. Thanks for your help on this!

[Codex]

This fixed the same issue for me. Thanks!