Creating 3D models

To create custom models I use BlockBench which is a free, easy to use and amazing tool to make Minecraft model.

Creating 3D model from a texture

Important

If you're using a non-vanilla texture (your .png file) you have to open the .json file of your model and do a little edit.

If your model is using a custom texture you have to make sure to put your namespace in front of the texture name. For example if you have this 3D model and the texture has this path: plugins\ItemsAdder\data\resource_pack\assets\my_items\textures\item\custom_item_1.png

 "textures":{
      "0":"item/custom_item_1"
   },

you have to add the namespace in front of it (my_items in my example, you have to use your namespace).

 "textures":{
      "0":"my_items:item/custom_item_1"
   },