The background is completely transparent

[lngex]

Using "Viewport Builder::with transparent(true)" to set transparency will result in shadow or translucency. I hope a function can be provided to achieve complete transparency.

[jayy-ahn]

Have you tried implementing fn clear_color to MyEguiApp?

impl MyEquiApp {
    fn new(...) {...}
    fn clear_color(&self, _visuals: &egui::Visuals) -> [f32; 4] {
        [0.0, 0.0, 0.0, 0.0]
    }
}

This made the window completely transparent in another project I'm working on.

[lngex]

Have you tried implementing fn clear_color to MyEguiApp?

impl MyEquiApp {
    fn new(...) {...}
    fn clear_color(&self, _visuals: &egui::Visuals) -> [f32; 4] {
        [0.0, 0.0, 0.0, 0.0]
    }
}

This made the window completely transparent in another project I'm working on.

Using this method will cause the window to be completely black

[lngex]

Implement clear color and return [0,0,0,0],But the window is not transparent

[jayy-ahn]

Try adding a CentralPanel with the frame filled with Color32::TRANSPARENT.

impl eframe::App for MyEguiApp {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        egui::Window::new("test").show(ctx, |ui| {
            ui.heading("hi");
        };
        egui::CentralPanel::default()
            .frame(egui::Frame::default().fill(Color32::TRANSPARENT))
            .show(ctx, |ui| {});
    }
    fn clear_color(...) {...}

[lngex]

I tried to do what you said, but it still didn't work as expected.

[lucasmerlin]

@jayy-ahn @lngex I'm curious if you're using the gl or the wgpu backend? Maybe that makes a difference?

[lngex]

@jayy-ahn@lngex我很好奇你是使用gl还是wgpu后端？也许这会有所不同？
I turned on the log, and the log shows the glow used.

[2024-09-24T13:38:30Z DEBUG eframe] Using the glow renderer
[2024-09-24T13:38:30Z TRACE eframe::native::run] Entering the winit event loop (run_on_demand)…
[2024-09-24T13:38:30Z TRACE eframe::native::run] winit event: NewEvents(Init)
[2024-09-24T13:38:30Z TRACE eframe::native::run] event_result: Wait
[2024-09-24T13:38:30Z TRACE eframe::native::run] winit event: Resumed
[2024-09-24T13:38:30Z DEBUG eframe::native::glow_integration] Event::Resumed

This works fine on my other computer, but on this one the background is always black