custom_item_models_attachable > rp > textures > terrain_texture.json
{
"resource_pack_name": "vanilla",
"texture_name": "atlas.terrain",
"padding": 8,
"num_mip_levels": 4,
"texture_data": {
"gmdl_1": {
"textures": "textures/blocks/geysercmd/gmdl_1"
}
}
}