Atlas crashes when modifying terrain elevation

[michael]

Atlas will freeze, then crash if I use the modify terrain elevation tool to change the terrain height on a map. This prevents me from modifying and creating maps.

[michael]

Unfortunately, the Atlas crash does not create a crashlog.

[historic_bruno]

Not reproducible here, on XP with integrated (non-shader) Intel graphics. If you start with a blank map in Atlas, it crashes as soon as you use the terrain elevation tools? Do the crashes go away if you remove the fancy graphics settings from your local.cfg? What is displayed when Atlas crashes, any error dialog?

[michael]

No error dialog, sadly. Atlas stops working, the UI goes blank, I see the "Not Responding" text at the top, I have to 'X' out multiple times before the Windows crash dialog appears ("pyrogenesis.exe has stopped working...").

Luckily, this time the mainlog generated a slew of warnings at the bottom:

Info when linking program 'shaders/glsl/model_common.vs'+'shaders/glsl/solid_tex.fs': Vertex info ----------- 0(115) : warning C7050: "cosVec.w" might be used before being initialized

Info when linking program 'shaders/glsl/model_common.vs'+'shaders/glsl/model_common.fs': Vertex info ----------- 0(115) : warning C7050: "cosVec.w" might be used before being initialized

Oddly enough, the game did not find these warnings to be interesting enough to add to the interestinglog.

Removing everything from local.cfg does not fix the problem.

[michael]

Running Windows debugger I get this:

​http://pastebin.com/Lt1y0tSx

[michael]

More debugging:

​http://pastebin.com/gL8XHSNb

[historic_bruno]

Was discussed on IRC ​2013-08-06 from 19:44. May be heap corruption based on the call stacks, if someone else can test Atlas on Windows 8 that would be good, and running valgrind's memcheck on Atlas might uncover something.

[michael]

Crash occurs when editing the terrain textures as well.

Debug output for this crash here:

​http://pastebin.com/xvFtd9eY

[historic_bruno]

Michael, can you check if you have the latest graphics drivers?

Also test if it helps to put novbo=true in your local.cfg.

[historic_bruno]

Others are reporting a crash in Atlas related to terrain modification, see IRC logs from ​2013-08-19 starting at 15:35 (independent of r13714 which is a fix for another crash). I still cannot reproduce an Atlas crash and valgrind is telling me nothing.

[michael]

novbo=true Seems to help for now. I'll report back if I get another crash.

[michael]

novbo=true Gives bad artifacts with sheep, Cretan Date Palms, Mauryan civ center, and other meshes. However, it does seem to help prevent Atlas crashes so far.

[historic_bruno]

Yeah, it's only meant for testing purposes :) But now we know there's a workaround for your crash - and more importantly, it's related to vertex buffers.

As for the artifacts you're seeing with novbo, Philip has found the likely cause of that (incorrect range being passed to glDrawRangeElements in model rendering, for more details see IRC logs ​2013-08-21 from ~19:02), so we'll fix that first. It might solve your original crash, if not, at least you'll have a workaround for using Atlas until it does get fixed.

[philip]

In 13734:

Fix rendering artifacts with novbo=true gentangents=true

glDrawRangeElements needs to know the range of vertexs that are used
by the index array. With VBOs it doesn't really matter if the range
is wrong (all the vertexes are in GPU memory anyway), but with CPU
vertex arrays the driver has to memcpy the given range of data, so
incorrect bounds will result in garbage data being rendered.

With gentangents, the rendered mesh can have more vertexes than the
original CModelDef, but was rendered with the CModelDef's vertex count.

Use the correct vertex count instead.

Refs #2050.

[historic_bruno]

Ok, the latest autobuild has Philip's fix. Can you try Atlas without novbo=true to see if it still crashes?

[michael]

novbo=false gives a crash within minutes of elevating the terrain. Crash happens as I am modifying/elevating the terrain and moving the camera (the camera bit may be superfluous).

novbo=true still seems to prevent any crash.

[historic_bruno]

Ok, we may need to do more in depth debugging of this after A14 release. It's probably not worth blocking the release for Atlas, and it's not an easy problem to reproduce :(

[historic_bruno]

This and #2081 are so far only reported by Michael.

[wraitii]

I'd venture and say it's probably linked to drivers...

[historic_bruno]

Reported by Michael in IRC that Atlas doesn't crash now, and is fairly stable. So I will close the ticket as "works for me". If the problem comes back, please reopen.