How to create an air distortion/blur effect in eevee?

Question

I would like to recreate an air distortion/blur effect like the ones seen in marvel vs capcom 3 to give more "punch" to my animations (images attached to give an idea of what im looking for)

Answer 1

One way to do it would be to play with Principled BSDF Transmission and IOR.

I modeled a crude Christmas tree like shape by taking a cylinder and adding some edge loops to it. Next I selected randomly some of the faces and extruded them along individual normals. Then I moved the extruded vertices down.

and set the Principled BSDF transmission to 1 and IOR to 1.01.

This basically means that the material is almost air but not quite. It's quite close to warm air with a lot of distortion.

Remember to check Screen Space Reflections under Render Properties and Refraction under Screen Space Reflections.

and Screen Space Refraction under Material properties.

Next I animated the object to scale up, follow a curve and vanish by changing IOR from 1.01 to 1.00.

Answer 2

I'm not sure it's possible due to the way EEVEE handles lighting and refraction calculations. I went with my intuition to try and create a node setup that could be used to warp the background similarly to what you showed (animating it, and making it "pop" in and out of existence is a later step). I tried adding this to a plane in front of the background. However, while I could get a rather convincing replica using Cycles, the same thing gives jack-all-nothing in EEVEE. See the images below:

Cycles

EEVEE (Nothing but disappointment)

To anyone reading - If I am incorrect, and there is in fact a way to do this, please feel free to share, as this would be a rather substantial answer.