Question No pixel art game occasional tilemap seams

In our game we have 2d art and 2d tile-maps with orthographic camera that zooms in and out during gameplay. The assets are configured with bilinear filter in the sprite atlas and with mipmapping enabled. This solution works for us but there are very occasional seams in our tilemaps (when moving the camera very occasionally one line crossing all tile layers and showing what's behind will show up).

I've tried everything that I can think of and could find: adding more padding to tiles, changing cell gaps, disabling/enabling anti aliasing, camera movement, disabling mipmapping....

My question is then: Is this unavoidable for our current setup?

Edit: sample project https://github.com/SwingWren/2d-ocasional-tile-seams-demo

 

• How did you add the padding?
• What is the content of padding?
• Is the camera significantly zoomed out when seams appear?

 

I was just creating a sample project, easier to see and change https://github.com/SwingWren/2d-ocasional-tile-seams-demo. Just press play and wait for the red lines to appear (the color of the camera background), you may need to be patient as sometimes it takes more times for the lines to show up.

 

normally atlas with padding = 2 solves this problem

however you using bilinear filter and mip maps might be messing with the solution

maybe try increasing padding to an unreasonable amount like 10, or 20, see what happens

 

It doesn't seem to help, either with minmaps or without minmaps enabled

 

As you can see the padding is added through sprite atlas.
The seams appear regardless of the zoom