Smooth interpolation in texture distort?

I have been playing around with sanch’s “distort by texture” with the idea of doing some big projected lines round people on walls. At the moment the interpolation/filtering between the pixels isn’t so great - – it looks very jagged when blown up by a projector. It would be great if we could maybe alter the shader so that it smoothes the jaggies out a little – would this maybe have anything to do with bilinear interpolation, or am i barking up the wrong tree?

I had a look at tonfilm’s bicubic shader and tried hacking that header into the distortion shader to see what effect that might have but it didn’t really work…seems way beyond my limited shader skills unfortunately. Any ideas on ways to get a smooth look going?

I’ve attached a screenshot and then also a shot of what ideally it’d look more like in terms of smoothness (done in after effects, using the same source image and distortion mask).

cheers…

filter distort.jpg (127.9 kB)