This resource pack is a template that allows you to completely disable vanilla shadow on item.

How does it work ?

It works using core shaders which allow in vanilla resource pack to change how the game render

How to use ?

1. Copy the folder "shaders" in your ressource-pack (or copy your texture-pack in my ressource-pack)

2. Then to disable shadow go to items/*your_item*.json and add those lines :

,
          "tints": [
            {
              "type": "minecraft:constant",
              "value": [1.0, 0.0, 0.0]
            }
          ]

for example :
paper.json \/

{
  "model": {
    "type": "select",
    "property": "custom_model_data",
    "fallback": {
      "type": "model",
      "model": "item/paper"
    },
    "cases": [
      {
        "when": "example",
        "model": {
          "type": "model",
          "model": "item/example",
          "tints": [
            {
              "type": "minecraft:constant",
              "value": [1.0, 0.0, 0.0]
            }
          ]
        }
      }
    ]
  }
}

. 3. Next go to models/item/*your_model*.json and add this line after "texture": "#[]":

, "tintindex": 0

for example :
example_model.json \/

{
	"textures": {
		"1": "item/example_model",
		"particle": "example_model"
	},
	"elements": [
		{
			"from": [4, 0, 4],
			"to": [8, 7, 12],
			"rotation": {"angle": 0, "axis": "y", "origin": [8, 3.5, 8]},
			"faces": {
				"north": {"uv": [9.5, 8, 11.5, 11.5], "texture": "#1", "tintindex": 0},
				"east": {"uv": [4.5, 0, 8.5, 3.5], "texture": "#1", "tintindex": 0},
				"south": {"uv": [11, 0, 13, 3.5], "texture": "#1", "tintindex": 0},
				"west": {"uv": [4.5, 3.5, 8.5, 7], "texture": "#1", "tintindex": 0},
				"up": {"uv": [4.5, 12, 2.5, 8], "texture": "#1", "tintindex": 0},
				"down": {"uv": [11.5, 4, 9.5, 8], "texture": "#1", "tintindex": 0}
			}
		},
    ...