• This problem is being reported to Firestorm support with increasing frequency now that the new Intel Skylake processors with Intel HD 500 series graphics are in wider use.

• Several of the affected users have verified that the problem happens on the current LL viewer - it reproduces on any viewer actually.

• I do not have a system which reproduces this problem myself but getting someone on an affected system to file a LL JIRA issue for this has proved fruitless so far, so I'm filing it as I believe I have enough information now for a valid report.

• I have no idea if this is even fixable in the viewer or whether it is a driver bug or a fault in the Intel 500 cards, but hopefully someone at LL has a system with Intel HD 500 series graphics and can reproduce this.

• This bug appears to be specific to only the new Intel HD Graphics 500 series cards.

• There are many different problems which can cause the viewer screen to flash but this one has very specific (& unfortuantely common) conditions that must be met to reproduce on the Intel HD 500 cards.

  Examples Of Affected Systems

  |Processor|Graphics Card|Driver Version|Open GL Version|Operating System|Notes|
  |
  |-|-|-|-|-|-|-|
  |Intel(R) Core(TM) i5-6400 CPU @ 2.70GHz (2712 MHz)|Intel(R) HD Graphics 530|10.18.0015.4271|4.2.0 - Build 10.18.15.4271|Microsoft Windows 10 64-bit (Build 10240)|Landru McCallen, verified repro on LL viewer|
  |
  |Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz (4007.99 MHz)|Intel(R) HD Graphics 530|10.18.0015.4279|4.2.0 - Build 10.18.15.4279|Microsoft Windows 10 64-bit (Build 10240)|Hazel Romano, verified repro on LL viewer|
  |
  |Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz (2496 MHz)|Intel(R) HD Graphics 520|10.18.0015.4293|4.2.0 - Build 10.18.15.4293|Microsoft Windows 10 64-bit (Build 10586)|Nyu Warblood, Surface 4 Pro|
  |
  |Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz (2591.98 MHz)|Intel(R) HD Graphics 520|10.18.0015.4248|4.2.0 - Build 10.18.15.4248|Microsoft Windows 10 64-bit (Build 10240)| Abbie Flagon. Optimus system luckily so fixed by switching to Nvidia card|
  |
  |Intel(R) Core(TM) i5-6200U CPU @ 2.30GHz (2400 MHz)|Intel(R) HD Graphics 520|10.18.0015.4279|4.2.0 - Build 10.18.15.4279|Microsoft Windows 10 64-bit (Build 10240)|Fullmetalone Resident|
  |
  |Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz (2591.99 MHz)|Intel(R) HD Graphics 530|20.19.0015.4352|4.2.0 - Build 20.19.15.4352|Microsoft Windows 10 64-bit (Build 10586)|Whirly Fizzle, THIS SYSTEM DOES NOT REPRODUCE THE BUG!|
  
  
  
  # Steps To Reproduce
  
  
  |

• Login on an affected system with an Intel(R) HD Graphics 500 series card.

• Either wear or stand near someone wearing any rigged mesh which has at least one face textured with a diffuse texture containing alpha which is set to alpha blending mode.

• I attached a simple rigged cube & diffuse texture to this issue which will reproduce the problem.
  There is nothing special about this mesh or texture though - the problem will reproduce with any worn rigged mesh with a diffuse texture set to alpha blending.

  • Upload the attached Test png texture to SL.

  • Upload the attached Rigged_Cube.dae to SL. "Include skin weight" must be enabled in the Upload tab of the mesh upload window.

  • Texture the rigged cube with Test png texture set as the diffuse texture. Set alpha mode to alpha blending.

    The following conditions must be met to reproduce the flashing:

• Worn rigged mesh in the scene which has at least one face textured with a diffuse texture containing alpha and set to alpha blending mode.
  Alpha masking and emissive mask mode do not reproduce the problem.
  Worn unrigged mesh does not reproduce the problem.

• If ALM is disabled the flashing will always reproduce unless Hardware skinning is disabled.

• If ALM is enabled the flashing will only reproduce when the avatar wearing the alpha blended rigged mesh is standing in or close to Linden water (Weird huh?)

• If Hardware Skinning is disabled, the flashing stops in this case too.

  Observed Behaviour

• Severe screen flashing where the repro meshes appear to explode constantly if the following conditions are met:
  When a repro mesh is worn by an avatar close to the person on an affected system with the following graphics settings, the bug will reproduce:

• ALM disabled + Hardware skinning enabled.

• ALM enabled + Hardware skinning enabled + Avatar wearing the mesh standing in Linden water.

• See the attached gifs showing examples of the screen flashing.

• Landru McCallen.gif shows a scene where only myself & Landru are present. I'm wearing a full body alpha with the rigged cube attachment textured with a single alpha blended diffuse texture - the orange box in the middle of the screen.
  As soon as I changed the texture to alpha masking+mask cutoff or emissive mask, the flashing ceased.

  Expected Behaviour

  No crazy flashing.

Attachments

• Hazel Romano .gif 2015-11-29 21:37:38
• Landru McCallen.gif 2015-11-29 21:37:38
• Plurk example.gif 2015-11-29 21:37:38
• Rigged_Cube.dae 2015-11-29 21:29:26
• Test png.png 2015-11-29 21:31:28

Links

Related

• [BUG-216113] Screen keeps glitching and making it impossible to do anything. #3572
• [BUG-216314] messed up screen #3716
• [BUG-225202] Viewer is having issues #4060

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