Render to user-supplied framebuffer

[akre54]

User Story

As a developer I want to be able to render the basemap layers to a framebuffer, similar to deck.gl's _framebuffer option.

Rationale

My goal is to composite these layers separately as Textures, in a program like Photoshop or After Effects, or to do postprocessing on the individual layer passes.

Impact

Right now I can capture the canvas after all layers have been composited, but I'd really like to be able to render just a few layers (say, roads, waterways, etc) to a Framebuffer for editing.

[HarelM]

Rendering to textures is not performant enough for the map. I also don't fully understand the use case. I guess you can create multiple maps one on top of the the other with only the relevant layers and preserve drawing buffet to get it out of the canvas...

[akre54]

Thanks for the quick reply. My goal is something similar to Blender's Shader Passes. Namely I want to be able to render the passes to AOVs (think normals map, depth buffer, shadows, lighting) to be able to use for video compositing.

Performance is less of a concern for me because frame capture is async. I'm mostly asking for a way to hook into the draw calls and get access to the rendering buffers. I can accomplish this in Deck by passing in a Framebuffer, but an alternative could be to add a callback in the render pipeline.

[HarelM]

This sounds like a very specific case. I'm not sure maplibre has the relevant hooks at the moment. The closest thing I can think of is using the webgl context in a custom layer, but that's not exactly what you need. A lot of the code is done in the shaders themselves too. I would recommend trying to hack out a plugin of some sort to do that, but I'm not sure I would know where to start...

[akre54]

Thanks @HarelM. I'll do some exploration.

IMO this has lots of other applications but if it's not something the maintainers want to support at the moment I'll try to find a workaround.