In dual monitor, Mesh disappears when Opensubdiv's on #48953

New Issue

Darío Baldi · 2016-07-27T03:08:28+02:00

Darío Baldi commented

2016-07-27 03:08:28 +02:00

I'm not sure if it's a bug or an Opensubdiv limitation.

System Information
Windows 7, NVDIA GTX 650

Blender Version
Tried in these versions and it didn't work in any.
2.76b - hash: f337fea
2.77 - hash: abf6f08
2.77 - hash: eececb0 (buildbot)

Short description of error
In a dual monitor set-up with 2 or more 3d View windows, mesh disappears when opensubdiv is on in all but one window. I tried with simple cube scene and with Victor's rig (CL) and couldn't reproduce the issue.

Exact steps for others to reproduce the error
Turn off/on open subdiv, mesh will appear/disappear. I attached a blend file of the scene.
Blend file: opensubdiv bug.blend
My system info:system-info.txt

Gif showing problem:

I'm not sure if it's a bug or an Opensubdiv limitation. **System Information** Windows 7, NVDIA GTX 650 **Blender Version** Tried in these versions and it didn't work in any. 2.76b - hash: f337fea 2.77 - hash: abf6f08 2.77 - hash: eececb0 (buildbot) **Short description of error** In a dual monitor set-up with 2 or more 3d View windows, mesh disappears when opensubdiv is on in all but one window. I tried with simple cube scene and with Victor's rig (CL) and couldn't reproduce the issue. **Exact steps for others to reproduce the error** Turn off/on open subdiv, mesh will appear/disappear. I attached a blend file of the scene. Blend file: [opensubdiv bug.blend](https://archive.blender.org/developer/F328482/opensubdiv_bug.blend) My system info:[system-info.txt](https://archive.blender.org/developer/F328479/system-info.txt) Gif showing problem: ![opensubdiv-bug.gif](https://archive.blender.org/developer/F328487/opensubdiv-bug.gif)

Darío Baldi commented

2016-07-27 03:08:28 +02:00

Changed status to: 'Open'

Darío Baldi commented

2016-07-27 03:08:28 +02:00

Added subscriber: @dario.baldi

Sergey Sharybin commented

2016-07-27 10:01:45 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2016-07-27 10:01:45 +02:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2016-07-27 10:01:45 +02:00

Sergey Sharybin self-assigned this 2016-07-27 10:01:45 +02:00

Sergey Sharybin commented

2016-07-27 10:01:45 +02:00

This is a known issue which was already reported here.

This is a specific behavior of how OpenGL and how we use it in Blender. The thing here is that for the performance gains Blender will use separate OpenGL contexts for different windows. But at the same time, so-called VAOs (Vertex Array Objects) are required for OpenSubdiv. Those are like the only ones who are not shared across different OpenGL contexts.

The difficult part here is that drawing code in Blender doesn't really know what window it operates in, what VAO will be relevant to it, how to create VAO when opening new window and destroying VAO when closing a window.

I didn't want to start hacking the system to add quick support for those, because it's like stressing drawing and window management code beyond it's limits, and we also have bigger plans on re-designing the whole drawing code in Blender for 2.8. So would rather invest time we work on really strong new design that trying to hack current limited design.

Thanks for the report, but it's a TODO for now.

This is a known issue which was already reported here. This is a specific behavior of how OpenGL and how we use it in Blender. The thing here is that for the performance gains Blender will use separate OpenGL contexts for different windows. But at the same time, so-called VAOs (Vertex Array Objects) are required for OpenSubdiv. Those are like the only ones who are not shared across different OpenGL contexts. The difficult part here is that drawing code in Blender doesn't really know what window it operates in, what VAO will be relevant to it, how to create VAO when opening new window and destroying VAO when closing a window. I didn't want to start hacking the system to add quick support for those, because it's like stressing drawing and window management code beyond it's limits, and we also have bigger plans on re-designing the whole drawing code in Blender for 2.8. So would rather invest time we work on really strong new design that trying to hack current limited design. Thanks for the report, but it's a TODO for now.

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In dual monitor, Mesh disappears when Opensubdiv's on #48953