Using texture for both input and output in redering

Hi there,

I would like to create some sort of ‘ripple’ effect in a texture. I’ve found several sources with algorithms on it, but I’m not sure on how to implement it yet in UE.

What I’v done before (outside) UE is to use a texture-buffer for both input and output from a shader. Then each pixel of the buffer can contain some information that is read by the shader, then processed, and then written to, for use in the next frame.
Is it possible to set something like this up in UE?

What I’ve tried so far:

point a “Scene capture 2D” at a box (aligned perfectly at one side).
Create a material that uses that SceneCapture2D
Apply the material to the box that the ‘SceneCapture2D’ is pointed at.
In my view this would create the ‘loop’ I wanted, the material is used for input, as well as output. And any effects applied should be additive. As a simple example I added some constant to the redness of each pixel, so I would have expected that each frame the redness would increase (because the increased redness would be used as an input for the next frame… right?). However, this does not seem to work as I expected (redness does not increase each frame). Probably because things are not implemented as straightforward as I thought.

Does anyone know how to this kind of thing? Or have an alternative for a ripple effect that is not too ‘expensive’ ?

Thanks!

I found out it is possible to do as I said, after some messing around it worked.
So if you point a sceneCapture2D at a billboard (for example) that shows the render target of that same sceneCapture2D, the render target is used both as input for the material, as well as the output.
However, lighting fails to calculate, it just hangs there at 50%… it might get stuck in a infinite loop because of the looped setup?