Help with pixel swimming in 3D pixel art game

[pertholdth]

Hello, I am making a game in this style:

timestamped link

And I am having some trouble in this part, as you see, the game is 3d but uses pixel art graphics

Since the camera is perspective, when you move north to south the geometry and sprites get naturally scaled by distance and on slow camera movements a lot of pixel swimming is noticeable

I have all sprites on point filter and no anti-alias so I am getting this effect on everything:

Now in a pixel perfect game this is fixed by snapping pixels to a grid, but this game is not pixel perfect, the pixel art gets scaled down by distance and so that method doesnt work here

I asked the devs of this game about their solution and they were very friendly and explained their approach to this problem like this:

Begin quote -

“a good workaround for this is not not render everything nearest neighbour but actually with linear interpolation, but sort of tweaking the texture coordinates in the fragment shader to reduce the smoothing
(you can do that quite easily when you know the resolution of the texture - it’s basically like snapping texture coordinates to the center of the pixel unless they are very close to the border between two pixels)
We also do some post processing pixel smoothing which is quite elaborite and the effect is very suble. The texture interpolation definitely has the bigger effect”

• End Quote

However they have their own engine so they are not using unity, and I am not skilled enough to interpret what they are expressing, I was hoping someone more knowledgeable could help me interpret this and translate on how I would apply this method in unity.

I have tried switching the sprites from point to bilinear but then it just looks blurry and doesnt look like pixel art anymore (though it does stop the pixel swimming completely, except on the edges of the sprite, I imagine for the edges I would have to turn on anti alias, but i dont understand how a shader will turn it back into pixel art look)

Thanks for any advice

[kdgalla]

@pertholdth

I was hoping someone more knowledgeable could help me interpret this and translate on how I would apply this method in unity.

Essentially add anti-aliasing. I don’t know if there is an AA option that is literally “linear” interpolation but they’re all interpolation of some kind.

Edit: aside from post processing, you could also add interpolation by rendering to a render-texture with bilinear filtering enabled. If it’s too blurry then make the render texture twice, three, or even four times your intended pixel resolution.