No active OpenGL context on RenderEngine.render #78921

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Miguel Pozo · 2020-07-14T17:28:50+02:00

Miguel Pozo commented

2020-07-14 17:28:50 +02:00

Could we get OpenGL working for F12 rendering on external render engines?

We're currently working on an OpenGL based render engine add-on. https://github.com/BlenderNPR/BEER

Viewport rendering works fine because when Blender calls the RenderEngine.view_draw function the OpenGL offscreen draw context is active, but there's no active context when RenderEngine.render (F12 render) is called.

I've tried to modify external_engine.c, taking eevee_engine.c as reference, to get OpenGL working on the render callback. But I got kind of lost.

@brecht @fclem @mano-wii

Could we get OpenGL working for F12 rendering on external render engines? We're currently working on an OpenGL based render engine add-on. https://github.com/BlenderNPR/BEER Viewport rendering works fine because when Blender calls the RenderEngine.view_draw function the OpenGL offscreen draw context is active, but there's no active context when RenderEngine.render (F12 render) is called. I've tried to modify external_engine.c, taking eevee_engine.c as reference, to get OpenGL working on the render callback. But I got kind of lost. @brecht @fclem @mano-wii

Miguel Pozo commented

2020-07-14 17:28:50 +02:00

Added subscriber: @pragma37

Brecht Van Lommel was assigned by Miguel Pozo

2020-07-14 17:36:12 +02:00

Miguel Pozo commented

2020-07-14 17:36:12 +02:00

Added subscribers: @fclem, @mano-wii, @brecht

Evan Wilson commented

2020-07-14 22:10:08 +02:00

Added subscriber: @EAW

Evan Wilson commented

2020-07-14 22:10:08 +02:00

(Possibly) Related: #77958, #54638 & D6585

(Possibly) Related: #77958, #54638 & [D6585](https://archive.blender.org/developer/D6585)

Brecht Van Lommel removed their assignment 2020-07-14 22:31:42 +02:00

Brecht Van Lommel commented

2020-07-14 22:31:42 +02:00

Changed status from 'Needs Triage' to: 'Archived'

Brecht Van Lommel closed this issue

2020-07-14 22:31:42 +02:00

Brecht Van Lommel commented

2020-07-14 22:31:42 +02:00

Feel free to submit a patch (even if it doesn't work at all and you have questions on how to proceed). But you can't create tasks here that you want other developers to work on.

https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests

Feel free to submit a patch (even if it doesn't work at all and you have questions on how to proceed). But you can't create tasks here that you want other developers to work on. https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests

Miguel Pozo commented

2020-07-14 23:30:51 +02:00

@EAW Thank you! #77958 is kind of similar.

@brecht I'm not asking any other developer to work on this. I'm literally just asking if this is an option.

Seems like it should be a somewhat trivial change so if it doensn't work already maybe there's a reason for it. (The offscreen context could be in use in another thread, for example)

I quoted the Render API and the GPU developers (https://wiki.blender.org/wiki/Modules) because I expected you could give me at least some basic information or point me in the right direction.

@EAW Thank you! #77958 is kind of similar. @brecht I'm not asking any other developer to work on this. I'm literally just asking if this is an option. Seems like it should be a somewhat trivial change so if it doensn't work already maybe there's a reason for it. (The offscreen context could be in use in another thread, for example) I quoted the Render API and the GPU developers (https://wiki.blender.org/wiki/Modules) because I expected you could give me at least some basic information or point me in the right direction.

Brecht Van Lommel commented

2020-07-14 23:54:40 +02:00

For discussion there is https://devtalk.blender.org. A task assigned to a developer means the developer is expected to do the task.

This should be an option, with a flag on the render engine to indicate if an OpenGL context is needed by the renderer. We don't want to create an OpenGL context for renderers that don't need it.

DRW_render_to_image has the code for Eevee, initializing/deinitializing the OpenGL context at the start/end of the function. This code could be moved from the draw module to the render module, and Eevee and Workbench would then set the flag to request an OpenGL context.

For discussion there is https://devtalk.blender.org. A task assigned to a developer means the developer is expected to do the task. This should be an option, with a flag on the render engine to indicate if an OpenGL context is needed by the renderer. We don't want to create an OpenGL context for renderers that don't need it. `DRW_render_to_image` has the code for Eevee, initializing/deinitializing the OpenGL context at the start/end of the function. This code could be moved from the draw module to the render module, and Eevee and Workbench would then set the flag to request an OpenGL context.

Miguel Pozo commented

2020-07-15 19:11:13 +02:00

In #78921#979150, @brecht wrote:
A task assigned to a developer means the developer is expected to do the task.

Noted, sorry for that.

I've submited a patch. D8305

> In #78921#979150, @brecht wrote: >A task assigned to a developer means the developer is expected to do the task. Noted, sorry for that. I've submited a patch. [D8305](https://archive.blender.org/developer/D8305)

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No active OpenGL context on RenderEngine.render #78921