Hotfix for Invisible Player and Creature Models

[Benjamin Arnold.3457]

We just shipped a hotfix that included a fix for player and humanoid creature models going permanently invisible, primarily in fractals. When the bug occurred, it would result in all future models failing to load and going invisible until a map swap.

This bug has been occurring for months, and we were having trouble finding a way to reproduce it. Thanks to clues from community reports, we were finally able to nail down a way to reproduce the bug consistently and thus were able to find the fix. The three key clues were:

1. It mainly occurs in fractals or dungeons. This told us it might have something to do with parties.
2. It doesn't occur with "Simple Party UI" checked, which pointed to party UI being involved.
3. It appears to happen most often when there is a weaver in the party, which happened to be due to a very specific skill, "Ride the Lightning"

It turns out there were actually two separate code bugs working in tandem with a particular skill and a specific timing, and that combination would result in the issue arising after repeated uses of the skill.

Please let us know if, after this fix, you notice anything else going strange with player or humanoid creature loading.

Thanks for your help in nailing this down!

[Benjamin Arnold.3457]

For those that like more information: The core issue was a model load interrupt resulting in dangling handle references to some textures in a global texture pool. Since the references never got cleared, we eventually ran into a situation where we had no textures left, resulting in a permanent loading failure while all future composite models waited for the textures to be available. The solution was to make sure that we always release the texture handles when our model loading is interrupted, along with making sure the party UI isn’t quite so overzealous on when it decides to reload models.

A lot of the early time without a repro was spent trying to figure out all the ways that models could go invisible, which led me to a lot of frustrating dead ends, thankfully it was not in vain.

[hornswroggle.8023]

@"Benjamin Arnold.3457" said:

2. It doesn't occur with "Simple Party UI" checked, which pointed to party UI being involved.

OMG So THATS why I never got this bug...

Congrats on squishing that pesky thing... must have been really satisfying

[Celsith.2753]

I'm so glad that this is fixed but what about in wvw? We have been dealing with a similar problem for at least the past 4 years, if not longer. Weapons go invisible, npc's go invisible, then you get either/or both your character going invisible or waypointing resulting in sitting in a loading screen for 5m+. People reported this issue time and time again, for months, detailing it's progression and that 'changes of state' seemed to hasten it along. Does this fix help with that too?

[Benjamin Arnold.3457]

@Celsith.2753 said:I'm so glad that this is fixed but what about in wvw? We have been dealing with a similar problem for at least the past 4 years, if not longer. Weapons go invisible, npc's go invisible, then you get either/or both your character going invisible or waypointing resulting in sitting in a loading screen for 5m+. People reported this issue time and time again, for months, detailing it's progression and that 'changes of state' seemed to hasten it along. Does this fix help with that too?

There may be other bugs that could cause things to go permanently invisible, but this bug certainly affected WvW. If you ever walked up to a keep and all the NPCs were invisible, it was probably this bug, and should be fixed.

[Benjamin Arnold.3457]

Party UI was not the only way that these texture handles could be orphaned, it was just the most common way to reproduce the issue. The fix should work for the other, less common ways to reproduce it.

[X T D.6458]

Thank you for finally fixing this bug, and like previously pointed out hopefully it fixes that annoying bug from occurring in WvW. Let me just leave some details here that I have noticed in WvW. It most often happens when spending at least an hour on the same map. Weapons and guard npcs would not render at all, many effects would also not render. Using a tonic can cause your character to go completely invisible. Also it occurs at the same time as the long loading screen bug, and I am sure the two are related. The only way to fix it is to change maps. Thanks.

[Illconceived Was Na.9781]

Stellar work, @Benjamin Arnold.3457 (and friends).(I enjoyed learning the backstory, too, for what was causing it and how you tracked it down. CSI: Game Developer.)

[Celsith.2753]

@Benjamin Arnold.3457 said:

@Celsith.2753 said:I'm so glad that this is fixed but what about in wvw? We have been dealing with a similar problem for at least the past 4 years, if not longer. Weapons go invisible, npc's go invisible, then you get either/or both your character going invisible or waypointing resulting in sitting in a loading screen for 5m+. People reported this issue time and time again, for months, detailing it's progression and that 'changes of state' seemed to hasten it along. Does this fix help with that too?

There may be other bugs that could cause things to go permanently invisible, but this bug certainly affected WvW. If you ever walked up to a keep and all the NPCs were invisible, it was probably this bug, and should be fixed.

I hope this is the case, thankyou very much.

[zealex.9410]

In Story time with Ben: Anet gets creative in their endeavor to limit the number of eles in fractals.

Claps to you good sir. :tongue:

[Cyninja.2954]

Whoop whoop, very nice find.

I was seldomly running into the bug myself (having simple party UI enabled) but am glad that people affected by it have been helped.

Great job and cool to read about what caused this.

[phs.6089]

So that was weaver, we played hide and seek with Amala for 20 minutes :)Thank you for information and hard work, to make our experience in fractals great again.

[AlraiLuxx.9413]

Thanks for doing a little behind the scenes write up. Always interesting to learn more about the game's internal workings.

[Yasi.9065]

@"Benjamin Arnold.3457" said:For those that like more information: The core issue was a model load interrupt resulting in dangling handle references to some textures in a global texture pool. Since the references never got cleared, we eventually ran into a situation where we had no textures left, resulting in a permanent loading failure while all future composite models waited for the textures to be available. The solution was to make sure that we always release the texture handles when our model loading is interrupted, along with making sure the party UI isn’t quite so overzealous on when it decides to reload models.

A lot of the early time without a repro was spent trying to figure out all the ways that models could go invisible, which led me to a lot of frustrating dead ends, thankfully it was not in vain.

Aww... you fixed it before I ever could experience it. My fractal static always was like "I dont see Arkk" "Yep invisible again" "No adds for me" "Wheres the anomaly!?!". It made me feel very excluded tbh ;p

And to think it was due to simple party UI.... thanks for the time spent hunting this down and fixing it :)

[Cyninja.2954]

While we are on grafic bugs, is there any eta to the black screen occurrences on nvidia cards? Has this issue even been reproduced internally?

I've had 3 in a 2 hour time window since the patch. Not sure if I've gotten unlucky or if this has increased (usual would be 1 every 2-3 days).

[Linken.6345]

Well done crushing this bug Ben&team.

[Deepcuts.9740]

Well done on fixing invisible mobs.Now it seems you broke the walls :)During today's Urban Battleground, some people could not see the walls.

[lunaeclipse.6843]

Ben deserves massive props for this. I'm not a programmer but i can't imagine how frustrating this bug was to fix.

Thank you so much.

[Marzina.3754]

I know this thread is old now, but thought I would post that I am continually seeing, or rather not seeing, invisible characters. New to the game and spun and after playing for 11 levels bought the upgrades and boosted one of my characters to 80. Now I am constantly running into this problem.

[Cyninja.2954]

@"Marzina.3754" said:I know this thread is old now, but thought I would post that I am continually seeing, or rather not seeing, invisible characters. New to the game and spun and after playing for 11 levels bought the upgrades and boosted one of my characters to 80. Now I am constantly running into this problem.

Check your setting for "Character Model Limit" under the Graphical Options tab. Make sure to set the limit up since having this setting low will result in less models being loaded and will result in some models not getting loaded, especially when a lot of things are happening.

If performance becomes an issue, it is better to reduce the quality in other areas like shadows, model quality or Antialiasing.