EGUI Textures

[rchiaramo]

Context: I’ve been working on a small program that will become a real time ray tracer. At this point, all I want is a window that opens and displays a panel on the left with data/controls, and then a central panel that will use wgpu to draw data that I put into an array of u8. The egui_app_demo and Custom3D was my learning template, and I basically got that up and running.

Along the way, I struggled with modifying the wgpu texture. In the end I solved my issue by sending the texture created in the constructor with device.new_texture along with the callback resources (instead of the uniform buffer that was sent in Custom3D), and then used queue.write_texture in the prepare method with new data.

I spent a lot of time trying to get TextureID and TextureHandle and such to work, but I ended up deciding that they were doing something a little different than what I wanted (but perhaps I’m wrong). I couldn’t understand why I could create a texture with device.create and even used renderer to get a TextureID, but couldn’t use any of those things to get a TextureHandle.

Am I correct in concluding that using commands like egui::Context::load_texture and TextureHandle::set are for using egui textures that you’d draw with e.g., ui.paint and aren’t interacting with the original wgpu texture? I’m clearly super confused about this issue.

More generally: I’ve looked at the wgpu tutorial, but feel like I’m miles away from understanding how this all works in a way where I can create something new on my own for whatever task I’m implementing.

Where can I learn more about render passes, textures, buffers, etc.? Later, when I want to start moving my (now) CPU based ray tracer to the GPU, I feel like I’m going to need to know a lot more about setting binding groups and buffers and creating new pipelines, instances…is there a resource where I can really get into the weeds?

Any suggestions would be appreciated! Thank you in advance.

[qzd1989]

I'm trying to working on the samething too.
I record the screen and get a loop, the loop produces wgpu::Texture continuously. I want to play it as a real-time video.
I haven't solve it.

[rchiaramo]

So I basically just use the callback function to paint the screen. Instead of sending an f32 like angle in the demo, I send a pixel array. Then in the prepare routine I call queue.write_texture...etc. (I'm doing something deliberately silly at the moment as I get my CPU ray tracer up and running...I build the pixel array with my CPU render routine and then just use wgpu to display the texture.)

I'm trying to figure out if there's another method to get access to the device and queue without going through the callback. In winit/imgui examples I've seen, the entire wgpu state is saved in a struct and available for use in the event loop, which is easy to follow. I'd like to know if I can do the same thing, or if I need to go through the callback. That's my current project...lol