Concrete (of any type) created using the slope option from the little chisel tool renders with a jarring shading gradient. I've included sloped blocks from ArchitectureCraft (link) as comparison.

Screenshots in the following order:

• List of mods
• Without optifine
• With optifine

ArchitectureCraft blocks form the closer strip, and LittleTiles blocks are next to it. Block types from closest to farthest: concrete, light grey concrete, coal, quartz block. I've included the latter two only for contrast. Interestingly enough, the problem only seems to affect concrete.

The only resource pack I'm using (link) does not affect concrete, and I'm using default shaders in the example.

Thanks, and keep up the great work!

Remove Optifine and it will work. Sorry, but there is nothing I can do about it.

I dug a little deeper: Setting smooth shadows to off completely removes the checkering effect, with or without Optifine.

Notice that the following is running Optifine with connected glass textures. I tested without Optifine too; it looks good too. However, smooth shadows to off displays hard borders between blocks with different light levels, so... it's still not really an option.

I'm not sure if this information changes anything at all, but thanks for looking into the issue anyways.

Yeah same with some shaders. I really hope those things don't occur in 1.15 anymore.

Just in case, same thing happens with non-slopes, without Optifine:

But only if tiles are next to normal blocks:

if ground is tiles too:

So as it isn't possible to fix, can you add an option (in chisel and adv. recipe) to keep full block sized tiles as tiles as a workaround?

Not entirely sure what is going on, but there are some issues which will be fixed in the next version.