Efficient way to sample screen for afterimage shader?

Help Shaders
1

Godot Version

4.2.2

Question

Hello, I’m going for a tracer effect kind of like this but more blurred:

Right now I have it working but it’s not very performant. My way of sampling the screen is with the following operations

var curr_image = $SubViewport.get_texture().get_image()
var texture = ImageTexture.create_from_image(curr_image)
material.set_shader_parameter("curr_texture", texture)

SubViewport is the view of the player, and I sample every few frames.
The shader averages the pixels together of 4 images it stores in it’s parameters to create an after image effect.

Is there anyway to make this more efficient? Maybe completely through shader code?

Thank you!

2

Is this what you are looking for?

3

Thanks for the reply

but not quite, in my use case I need to store the current view for a few frames. So I can average them over time to create an afterimage.

With pure shader code I couldn’t find a way to store data in memory for operations a few frames later. But if there was a way it would definitely be more efficient than gdscript.