I can't see any textures of things like the mechanical belt and that stuff. I can see things like motors and pipes but that's it.

I have the same problem too, here's evidence

Can you send a screenshot? And do you have optifine/sodium/chlorine?

Did you install Flywheel with Create 0.3.1? If so, that caused it, remove Flywheel to fix it, or update Create if it won't break the pack you're playing.

The same problem occurs when I use flywheel-0.2.3 and create-0.3.2d and sodium-forge-2.9.10,but there is no problem when I replace it with OptiFine_1.16.5_HD_U_G8.

This is a compatibility issue with sodium-forge, removing it should solve the issue.

As mentioned in #2115, this bug appears to have been introduced with Create 0.3.2d, Flywheel 0.2.3, or both, as the previous versions do not experience this with Sodium Reforged 2.9.10 installed.

Duplicate of #2115