[Visual bug] Lines appearing above some blocks

[Demirath]

Description of Issue

Blocks with 2d textures, such as crops, fire, grass, flowers, and amethyst display thin lines "above" them (away from the anchoring block) when viewed from nearly edge-on. The lines appear to be a partial, upside-down version of the texture.

Some examples:

Steps to Reproduce

1. Install Optifine 1.21.4
2. Stand so that a 2d texture nearly, but not quite, disappears

OptiFine Version

OptiFine HD U J3 for Minecraft 1.21.4

Installation Method

Standalone

F3 Debug Screenshot

Prior Testing

• Does this happen in Vanilla without OptiFine? No.

Additional Information

This may be related to another bug with flat textures, where fire displayed at the bottom of the screen is a featureless semitransparent rectangle:

[GeForceLegend]

Those lines are side effects of Optifine using mipmap on those blocks. In vanilla those blocks have mipmap disabled when rendering.

This may work as intended if Optifine behaves same without shaders previously. However, I would suggest do not merge cutout and cutout_mipped without shaders enabled.