So, you’ve poured your heart and soul into crafting a custom item or block for your game. You’ve got the textures perfect, the functionality nailed down, and now you want players to actually *create* it. The standard crafting methods just don’t cut it, and you need something more…structured. You want a recipe where the arrangement of ingredients matters, a true shaped recipe. This guide will walk you through the process of transforming your custom recipe type into a functioning shaped recipe.
What exactly *is* a shaped recipe? It’s a crafting recipe where the placement of ingredients within the crafting grid dictates the outcome. Think about the iconic wooden pickaxe. The planks and sticks *must* be arranged in a specific ‘T’ formation, or you’ll end up with…nothing! That’s the power of shaped recipes. They allow you to create intuitive and engaging crafting experiences.
The goal of this article is straightforward: to equip you with the knowledge and code necessary to register your custom recipe type and make it behave just like those familiar shaped recipes you see every day in your favorite games. We’ll break down the essential components and provide practical examples to guide you through the process.
This guide assumes you have a basic understanding of modding, particularly within the framework. This includes creating custom items and blocks, understanding the basics of JSON configuration, and working with your platform’s existing recipe systems. If you’re completely new to modding, I recommend taking some time to familiarize yourself with the fundamentals before diving into this more advanced topic.
Understanding Recipe Types and Recipe Serializers
Let’s begin by exploring the core concepts of recipe types and recipe serializers. These are the building blocks that will allow us to define and implement our custom shaped recipe.
Recipe Types
Think of recipe types as labels that distinguish different kinds of crafting recipes. These labels let the game know the purpose of the recipe, like crafting, smelting, or blasting. Minecraft/your game provides built-in recipe types, like `crafting_table`, `smelting`, and `campfire_cooking`. For our custom recipes, we’ll need to forge our unique recipe type. This will tell the game, “Hey, this is a special type of recipe that needs to be handled differently.”
Here’s a simplified code snippet that illustrates the registration of a recipe type (note: this is a placeholder and needs adaptation for your chosen platform):
// Example (Conceptual - needs platform-specific implementation)
public static final RecipeType<MyCustomRecipe> MY_RECIPE_TYPE =
RecipeType.register("mymod:custom_crafting");
This code snippet registers a recipe type with the ID `”mymod:custom_crafting”`. Remember to adapt the namespace `”mymod”` to your own mod’s unique identifier to prevent conflicts.
Recipe Serializers
The recipe serializer acts as a translator between the recipe data stored in a JSON file and the usable recipe object in your code. It handles the crucial job of reading recipe data from those easily editable JSON files and converting it into something the game can understand. Conversely, it can also write recipe data back to JSON, which is helpful for data packs or dynamic recipe generation.
For shaped recipes, the JSON format typically includes a “pattern” representing the layout of ingredients in the crafting grid, “keys” mapping characters in the pattern to specific ingredients, and a “result” defining the item produced.
Here’s a simplified code example of a recipe serializer class (again, this is a placeholder and requires platform-specific implementation):
// Example (Conceptual - needs platform-specific implementation)
public class MyCustomRecipeSerializer implements RecipeSerializer<MyCustomRecipe> {
@Override
public MyCustomRecipe fromJson(ResourceLocation recipeId, JsonObject json) {
// Code to parse the JSON and create a MyCustomRecipe object
return null; // Placeholder
}
// (Optional) toJson method for writing recipes to JSON
}
The `fromJson()` method is where the magic happens. It’s responsible for parsing the JSON data and creating an instance of your custom recipe class.
Implementing the Recipe Class
This is where we breathe life into our shaped recipe. We’ll create a custom recipe class that defines how our recipe functions.
Crafting a Custom Recipe Class
First, create a class that inherits from the appropriate base class or interface, like `IRecipe` or `Recipe`. This class will store all the information about the recipe, including the pattern of ingredients, the list of ingredients themselves, and the final product.
Key Methods to Implement
This class needs to implement several key methods:
* `matches(Inventory inv, World world)`: This is the heart of your shaped recipe logic! It determines whether the items in the crafting grid match the recipe’s pattern. We’ll delve into this one in detail shortly.
* `assemble(Inventory inv)`: This method is called when the recipe matches. It returns the resulting item stack.
* `canCraftInDimensions(int width, int height)`: This method checks if the recipe can be crafted in the current crafting grid size. For a standard crafting table, this would be typically `true`.
* `getRecipeType()`: This method simply returns the custom recipe type you registered earlier.
* `getSerializer()`: This method returns the custom recipe serializer you’ll create in the next step.
Detailed `matches()` Implementation
The `matches()` method is where you’ll implement the pattern-matching logic. You’ll iterate through the crafting grid and compare the items in each slot to the corresponding character in the recipe’s pattern.
Here’s a breakdown of the logic:
* First, iterate through the crafting grid (usually a two-dimensional array representing the slots).
* For each slot, compare the item in that slot to the corresponding character in the recipe’s pattern.
* Use the ingredient list to efficiently check if the item in a slot matches any of the valid ingredients for that character. This is where `Ingredient.test(ItemStack)` comes in handy, allowing you to check if an item stack is a valid ingredient without writing complex comparisons.
* Handle empty slots gracefully. You might want to allow empty slots in certain positions or require specific items.
Here’s a simplified code snippet demonstrating the core logic of the `matches()` method:
// Example (Conceptual - needs platform-specific implementation)
@Override
public boolean matches(CraftingInventory inv, Level world) {
for (int i = 0; i <= inv.getWidth() - patternWidth; i++) {
for (int j = 0; j <= inv.getHeight() - patternHeight; j++) {
if (checkMatch(inv, i, j, false)) {
return true;
}
if (patternMirrored && checkMatch(inv, i, j, true)) {
return true;
}
}
}
return false;
}
private boolean checkMatch(CraftingInventory inv, int startX, int startY, boolean mirrored) {
for (int x = 0; x < patternWidth; x++) {
for (int y = 0; y < patternHeight; y++) {
Ingredient ingredient = ingredients[patternWidth * y + x];
ItemStack stack = inv.getItem(startX + x + (startY + y) * inv.getWidth());
if (!ingredient.isEmpty() && !ingredient.test(stack)) {
return false;
}
}
}
return true;
}
`assemble()` and Result Creation
The `assemble()` method is relatively straightforward. You simply use the result defined in your recipe data to create the item stack to return. This is what players will receive when they craft your item.
If your recipe involves container items (like buckets or bottles), you’ll need to handle those appropriately. For example, you might want to return an empty bucket after crafting a potion.
Implementing the Recipe Serializer
Now, let’s create the serializer that will handle the JSON parsing.
Crafting a Custom Recipe Serializer Class
Create a class that inherits from the appropriate `RecipeSerializer` interface. This class will contain two key methods: `fromJson()` and, optionally, `toJson()`.
Key Methods to Implement
* `fromJson(JsonObject json)`: This is where you’ll parse the JSON data from the recipe file. It’s responsible for extracting the pattern, keys, and result and creating an instance of your custom recipe class.
* `toJson(Recipe recipe)`: This method is optional but useful for data packs or dynamic recipe generation. It converts a recipe object back into JSON format.
Parsing the JSON (`fromJson()`)
Inside the `fromJson()` method, you’ll need to extract the various parts of the recipe from the JSON object.
* Getting the Pattern: Extract the pattern array from the JSON object. This is typically an array of strings representing the rows of the crafting grid.
* Getting the Keys (Ingredient Mappings): Extract the keys object from the JSON object. Each key maps a character in the pattern to an ingredient.
* Creating `Ingredient` objects: Use the platform’s specific method (e.g., `Ingredient.fromJson(JsonObject)`) to create `Ingredient` objects from the ingredient data in the JSON.
* Getting the Result: Extract the result object from the JSON and create the output `ItemStack`.
Crucially, you need to include error handling to gracefully handle invalid JSON formats or missing data. Use `JsonSyntaxException` (or its equivalent in your platform) to signal errors.
Here’s a simplified code snippet illustrating the core parsing steps:
// Example (Conceptual - needs platform-specific implementation)
@Override
public MyCustomRecipe fromJson(ResourceLocation recipeId, JsonObject json) {
JsonArray patternArr = JsonHelper.getAsJsonArray(json, "pattern");
List<String> pattern = new ArrayList<>();
for (int i = 0; i < patternArr.size(); ++i) {
pattern.add(JsonHelper.convertToString(patternArr.get(i), "pattern[" + i + "]"));
}
JsonObject keyJson = JsonHelper.getAsJsonObject(json, "key");
Map<Character, Ingredient> key = new HashMap<>();
for (Map.Entry<String, JsonElement> entry : keyJson.entrySet()) {
if (entry.getKey().length() != 1) {
throw new JsonParseException("Invalid key entry: '" + entry.getKey() + "' is an invalid symbol (must be 1 character only).");
}
if (" ".equals(entry.getKey())) {
throw new JsonParseException("Invalid key entry: ' ' is a reserved symbol.");
}
key.put(entry.getKey().charAt(0), Ingredient.fromJson(entry.getValue()));
}
JsonObject resultJson = JsonHelper.getAsJsonObject(json, "result");
ItemStack result = ShapedRecipe.itemStackFromJson(resultJson);
return new MyCustomRecipe(recipeId, pattern, key, result);
}
Registering the Serializer
You’ll need to register your custom recipe serializer with the game. The specific code for this will depend on your platform, but it usually involves registering the serializer with the appropriate registry.
Registering the Recipe Type
Creating a Registry Object
Here, you’ll want to create an object that stores the custom recipe type, usually using a Registry Object.
public static final RegistryObject<RecipeType<YourRecipe>> RECIPE_TYPE = RegistryObject.create();
Creating a Registry Event
Lastly, a Registry Event will be needed to register the recipe.
Creating JSON Recipe Files
The final piece of the puzzle is creating the JSON recipe files that will define your shaped recipes.
Folder Structure
The JSON recipe files typically go into a specific folder structure within your mod’s assets directory. The exact structure depends on the platform, but it’s often something like `data/
JSON Example
Here’s a complete example of a JSON file for a shaped recipe that uses your custom recipe type:
{
"type": "mymod:custom_crafting",
"pattern": [
"III",
" S ",
" S "
],
"key": {
"I": {
"item": "minecraft:iron_ingot"
},
"S": {
"item": "minecraft:stick"
}
},
"result": {
"item": "mymod:iron_hammer",
"count": 1
}
}
* `”type”`: Specifies the custom recipe type you registered earlier.
* `”pattern”`: Defines the shape of the recipe in the crafting grid.
* `”key”`: Maps each character in the pattern to a specific ingredient.
* `”result”`: Specifies the output item and the number of items produced.
Namespace Considerations
Always use a unique namespace for your recipes to avoid conflicts with other mods.
Testing and Debugging
Once you’ve implemented all the code and created the JSON recipe files, it’s time to test your creation.
Loading and Validation
First, check that your recipes are loading correctly when the game starts. Look for any errors in the console or log files related to recipe loading.
Crafting In-Game
Next, verify that your recipes appear in the crafting table or crafting interface and that they produce the correct output.
Debugging Tips
Here are some debugging tips:
* Add logging statements in your `matches()` method to help debug why a recipe isn’t matching.
* Use a debugger to step through the code and examine the values of variables during recipe matching.
* Check for common errors like incorrect JSON syntax, incorrect ingredient IDs, or typos in the pattern.
Advanced Considerations (Optional)
Here are some more advanced topics to consider:
* Recipe Book Integration: Integrate the created recipe in the recipe book in the game
* Data Pack Compatibility: Ensure that created recipe is compatible with data packs.
* Dynamic Recipes: Generating recipes dynamically instead of static JSON files
Conclusion
Congratulations! You’ve now learned how to create a custom recipe type that functions as a shaped recipe. This powerful technique allows you to craft complex and engaging crafting recipes for your custom items and blocks, adding depth and interest to your mod.
I encourage you to dive deeper into your platform’s documentation, experiment with different recipe configurations, and continue pushing the boundaries of what’s possible. Go forth and create amazing crafting experiences!
