classes/class_renderingdevice

[giscus[bot]]

classes/class_renderingdevice

Inherits: Object Abstraction for working with modern low-level graphics APIs. Description: RenderingDevice is an abstraction for working with modern low-level graphics APIs such as Vulkan. Compared...

https://docs.godotengine.org/en/stable/classes/class_renderingdevice.html

[acui]

I made an example on using the RenderingDevice and draw_list to build a customized pipeline and output the result to screen.
https://github.com/acui/customized-pipeline

[Agakitsune]

Good example, but instead of using screen_get_framebuffer_format, it's better to create a new framebuffer format with framebuffer_format_create or to get the format from the framebuffer RID with framebuffer_get_format because when creating the render pipeline, it uses a Render Pass that is not optimal for the frambuffer (wrong color format, no depth/stencil attachment)

[acui]

Thanks. I have updated the code to use the format of the render framebuffer.

[chokomancarr]

If you want to run a compute shader in a separate thread by using local rendering devices (to be able to use submit() and sync() and avoid stalling the rendering thread by doing work in parallel), you can actually share textures between rendering devices, despite the docs for create_local_rendering_device saying:

Cannot draw to the screen nor share data with the global RenderingDevice.

the trick is to create the texture in the main thread and share it with the compute thread for updating:

## main thread
var rd := RenderingServer.get_rendering_device()
var fmt : RDTextureFormat = ...
var view : RDTextureView = ...
var texture := rd.texture_create(fmt, view)
var texture_resource := rd.get_driver_resource(RenderingDevice.DRIVER_RESOURCE_TEXTURE, texture, 0)

# pass `texture_resource` (which is just an integer) to your compute thread...

## compute thread
var rd := RenderingServer.create_local_rendering_device()
# put the resource value in the `image` argument, and other formats should match `fmt` above
var texture := rd.texture_create_from_extension(RenderingDevice.TEXTURE_TYPE_2D, ..., texture_resource, ...)

# now you can write to `texture` here and it will be reflected on the main thread after `submit()`!

[chokomancarr]

the only limiting factor here is that texture_create_from_extension doesn't accept mipmap count as of 4.4, so you can only write to the base mipmap (see 105570). Also this doesn't work for non-texture resources.

[Calinou]

Note that the issue linked above is fixed as of 4.5.