UE4 C# RPG Core APIs

RPG Core APIs Sample

This sample demonstrates how to implement core RPG mechanics using Unreal Engine 4's C# APIs. We'll cover character stats, inventory management, and basic combat logic.

Character Stats Component

Create a component to manage character attributes like Health, Mana, Strength, etc.

                    
                        using UnrealEngine.Core.Components;
                        using System;

                        namespace MyGame.Components
                        {
                            public class CharacterStatsComponent : ActorComponent
                            {
                                // Base stats
                                public int MaxHealth { get; private set; } = 100;
                                public int CurrentHealth { get; private set; } = 100;
                                public int MaxMana { get; private set; } = 50;
                                public int CurrentMana { get; private set; } = 50;
                                public int Strength { get; private set; } = 10;

                                // Events for health/mana changes
                                public event Action<int, int> HealthChanged;
                                public event Action<int, int> ManaChanged;

                                public void TakeDamage(int damageAmount)
                                {
                                    CurrentHealth -= damageAmount;
                                    CurrentHealth = Mathf.Clamp(CurrentHealth, 0, MaxHealth);
                                    HealthChanged?.Invoke(CurrentHealth, MaxHealth);

                                    if (CurrentHealth == 0)
                                    {
                                        // Handle death logic
                                    }
                                }

                                public void UseMana(int manaCost)
                                {
                                    if (CurrentMana >= manaCost)
                                    {
                                        CurrentMana -= manaCost;
                                        ManaChanged?.Invoke(CurrentMana, MaxMana);
                                    }
                                }

                                // Add methods for restoring health/mana, leveling up, etc.
                            }
                        }
                    
                

Inventory System

Implement a basic inventory using a list or dictionary to store items.

                    
                        using System.Collections.Generic;

                        namespace MyGame.Inventory
                        {
                            public class Item
                            {
                                public string Name{ get; }
                                public string Description{ get; }
                                // Add item properties like type, effects, stack size
                            }

                            public class InventoryManager
                            {
                                private List<Item> items = new List<Item>();

                                public void AddItem(Item itemToAdd)
                                {
                                    items.Add(itemToAdd);
                                    // Trigger UI update event
                                }

                                public bool RemoveItem(Item itemToRemove)
                                {
                                    bool removed = items.Remove(itemToRemove);
                                    // Trigger UI update event
                                    return removed;
                                }

                                public IReadOnlyList<Item> GetItems()
                                {
                                    return items.AsReadOnly();
                                }

                                // Add methods for using items, equipping items, etc.
                            }
                        }
                    
                

Combat System

A simplified combat logic where characters attack each other, applying damage based on stats.

                    
                        using UnrealEngine.Core;
                        using MyGame.Components;
                        using System;

                        namespace MyGame.Combat
                        {
                            public static class CombatSystem
                            {
                                // Simple damage calculation
                                public static int CalculateDamage(CharacterStatsComponent attackerStats, CharacterStatsComponent defenderStats)
                                {
                                    int baseDamage = attackerStats.Strength * 2;
                                    // Add modifiers from weapons, skills, etc.
                                    return baseDamage;
                                }

                                public static void PerformAttack(Actor attacker, Actor target)
                                {
                                    CharacterStatsComponent attackerStats = attacker.GetComponentOfType<CharacterStatsComponent>();
                                    CharacterStatsComponent targetStats = target.GetComponentOfType<CharacterStatsComponent>();

                                    if (attackerStats != null && targetStats != null)
                                    {
                                        int damage = CalculateDamage(attackerStats, targetStats);
                                        targetStats.TakeDamage(damage);
                                        // Play attack animation, sound effects, etc.
                                        Log.Info($"{attacker.Name} attacked {target.Name} for {damage} damage.");
                                    }
                                }
                            }
                        }
                    
                

Integration with Game World

These components and systems would be attached to Actors in your Unreal Engine game world. For example, a Player Character Actor might have a CharacterStatsComponent and an InventoryManager.