Slate is a graphics library developed by Epic Games and used in UE4 editor and can be used in games (no engine matter) and standalone desktop apps and mobile apps.

But How is it rendered? with openGL or DirectX etc… (On GPU) or on CPU like how Windows Forms rendered?

If rendered in GPU ; why osd is not working? (actually it dosent work also with ViewPort that should be rendered on GPU)

If rendered in CPU ; why in windows task manager Editor is using Gpu 3D performance even when we are in blueprint editor with no 3D scene.

and Is there any thing like OpenGL but for CPU so for example I can make my own UI framework?

Slate is going to be directX, and the blueprint rendering will be DirectX as well. Which is why you see it has 3d performance in the blueprint editor. Blueprints are going to be using textures/Lines/quads in directx.

Slate is just their UI rendering engine. I'm not sure how to use it oustide of Unreal Engine. If you want to build windows native UI elements (like a game editor, text editor, microsoft word), then you can look at some things like WxWidgets which is cross platform.

If you want in-game UI rendering, then you can write a simple one if you know DirectX, or figure it out with the game-engine you are using (Unity/Unreal etc).

Thanks. but why I cant see any osd even in 3d viewport?

Thanks. but why I cant see any osd even in 3d viewport?

We dont see osd in cry engine because it is using MFC and QT but we can see in cryengine's 3d view

What is osd?

osd is a tool for gamers which puts some text/graph about fps, hardware usage in opengl/DirectX context

so the games can see what is the fps, cpu/gpu/ram etc usage.

I use that to detect which application in using OpenGL/DirectX