This allows you to add custom textures to renamed items, which can make custom textures for servers such as hypixel skyblock and Viper HCFactions (which is what im using it for :)
Here is what I put for the .properties file, use it kinda like a template lol:
type=item
items=minecraft:egg
texture=./rage_ball.png
nbt.display.Name=ipattern:*Rage Ball*
If i didnt explain the properties file enough in the video, the second line is for what the item is in minecraft, the third is referring to the texture that you want to add, and the last line is for the name of the item, excluding the bold or color characters.
Also if you want to change the texture of the enchanted golden apple, use this for the properties file:
type=item
matchItems=minecraft:golden_apple
texture=./gapple.png
damage=1
If you cannot see the custom items, check in optifine video settings, under quality there is a setting to enable custom items, make sure that is enabled!!!!
Comment any other resource pack vids i should make or any problems you are having!!! I hope this helped!!