For connected and emissive textures Optifine required for 1.12 and Fusion required for 1.21.
I was inspired by Ore Highlighter created by Zyrphox and Visible Ores created by Techy69.
Mod support 1.12:
Galacticraft;
Immersive Engineering;
Tinkers Construct;
Thermal Foundation.
Mod support 1.21:
None for now
Note: If you get "OpenGL Error: 1281 (Invalid value)" go to Video Settings > Performance and set "Render regions" to OFF (source)
Note2: If emissive textures doesn't work, try to reload resource pack by pressing F3+T, it needed only first time per client launch
