Warp 3d plane to 2d screen space GLSL:

gistfile1.txt

    uniform sampler2D uTexture;
    uniform float uAspect; //Aspect ratio of the screen
    uniform float uProgress;

...
at the end of the vertex shader:

        vec4 worldPosition = projectionMatrix * modelViewMatrix * vec4(pos, 1.);
        vec4 screenPosition = vec4((uv-.5)*2.,0.,1.);
        ivec2 texDim = textureSize(uTexture,0);
        float imageAspect = float(texDim.x) / float(texDim.y);
        if(imageAspect > uAspect)
          screenPosition.y = screenPosition.y * uAspect / imageAspect;   
        else
          screenPosition.x = screenPosition.x / uAspect * imageAspect;
        gl_Position = mix(worldPosition,screenPosition, uProgress);

https://codesandbox.io/p/sandbox/shader-forked-xp469x