that won't be a drop then, my bad. if "item A from mod A is REQUIRED to make item B from mod B", then here is the answer:
public override void AddRecipes()
{
ModRecipe recipe = new ModRecipe(mod);
recipe.AddIngredient(74,9999);//this is vanilla item, just change the 74 to the id you want. id is easy to find with terraria official wiki.
recipe.AddIngredient(null, "GodEmblem"); // this is how you add item as an ingredient from the same mod
recipe.AddIngredient(GetItem("UniversalCraftingMaterial"), 10);// this is how you add MULTIPLE item as an ingredient from the same mod
recipe.AddIngredient(ModLoader.GetMod("CalamityMod").ItemType("YharimsCrystal"));//this is how you can add the "Yharim's Crystal" from "Calamity" as an ingredient
recipe.AddIngredient(ModLoader.GetMod("Fargowiltas").ItemType("UniverseSoul"));//this is how you can add the "Soul of Universe" from "Fargowiltas" as an ingredient
recipe.AddTile(412);//this is the required crafting station.412 is ancient manipulator. more info is on the official wiki
recipe.SetResult(this);//so obviously this method is in that class or the "this" keyword won't work
recipe.AddRecipe();
}
last but not least, just a little hint: you can get the mod id in the mods folder which can be easily found by click 2 buttons in game menu.(Mods-open mods folder) some mod name and mod id is different. the name is a piece of
, but the id MATTERS.
also, just in case you need, i will show you the mod I wrote. nothing else, just hell lot of recipes depends on an item I created called "Universal Crafting Material", which can be dropped from every mob in the game.