Create a Dynamic Dialogue UI with TextMeshPro in Unity

Posted by Gemma Ellison

July 11, 2025

So, you’re venturing into the world of game development, and you want to add some engaging conversations to your game? Excellent choice! Dialogue systems can breathe life into your characters and make your game world feel more interactive. But let’s be honest: getting started can feel daunting. That’s where TextMeshPro comes in – and this guide. We’re not just going to build a dialogue system; we’re going to build your dialogue system, customized and ready to expand. Forget generic tutorials. Let’s dive into how to create a robust and flexible dialogue UI using TextMeshPro in Unity.

Setting Up Your Scene and TextMeshPro

First, let’s address the elephant in the room: why TextMeshPro? The answer is simple: crisp, clear text, regardless of resolution. This is crucial for a professional-looking UI.

Step 1: Import TextMeshPro. Navigate to Window > Package Manager and search for "TextMeshPro". Install it. Don’t skip this step! Your future self will thank you.

Step 2: Create the UI Canvas. Right-click in your Hierarchy and select UI > Canvas. Ensure the Render Mode is set to “Screen Space - Overlay” for simplicity. (Consider “Screen Space - Camera” for more advanced setups later.)

Step 3: Add a Panel for Dialogue. Right-click on your Canvas and select UI > Panel. This will be the background for your dialogue box. Adjust its size and color to your liking. Anchor it to the bottom of the screen for easy viewing.

Step 4: Create the Text Display. Right-click on your Panel and select TextMeshPro > Text - TextMeshPro. This is where the dialogue text will appear. Scale the text box to fit comfortably within the panel, leaving space for a character name or portrait.

Common Pitfall: Forgetting to set the RectTransform anchors correctly. Anchors determine how the UI element scales with different screen sizes. Spend time understanding them – it’s a lifesaver.

Scripting the Dialogue Manager

Now, let’s get to the heart of the system: the Dialogue Manager script. This script will handle displaying text and managing dialogue flow.

Step 1: Create a C# Script called "DialogueManager".

Step 2: Define a Dialogue Data Structure. Create a simple data structure (e.g., a class or struct) to hold the dialogue text and any branching options.

[System.Serializable]
public class DialogueLine
{
    public string speakerName;
    public string text;
    public DialogueOption[] options;
}

[System.Serializable]
public class DialogueOption
{
    public string text;
    public int nextLineIndex;
}

Step 3: Implement the DialogueManager Script.

using TMPro;
using UnityEngine;
using UnityEngine.UI;

public class DialogueManager : MonoBehaviour
{
    public TextMeshProUGUI speakerNameText;
    public TextMeshProUGUI dialogueText;
    public Button[] optionButtons;
    public GameObject dialoguePanel;

    public DialogueLine[] dialogueLines; // Array of dialogue lines
    private int currentLineIndex = 0;

    void Start()
    {
        // Initially hide the dialogue panel
        dialoguePanel.SetActive(false);

        //Optional: You could load dialogue from a JSON file here. This would be more scalable.
        //Example: dialogueLines = LoadDialogueFromJson("dialogue.json");
    }

    public void StartDialogue()
    {
        dialoguePanel.SetActive(true);
        currentLineIndex = 0;
        DisplayDialogueLine(dialogueLines[currentLineIndex]);
    }

    public void DisplayNextLine()
    {
        currentLineIndex++;

        if (currentLineIndex < dialogueLines.Length)
        {
            DisplayDialogueLine(dialogueLines[currentLineIndex]);
        }
        else
        {
            EndDialogue();
        }
    }

    private void DisplayDialogueLine(DialogueLine line)
    {
        speakerNameText.text = line.speakerName;
        dialogueText.text = line.text;

        //Handle Options
        if (line.options != null && line.options.Length > 0)
        {
            EnableOptions(line.options);
        }
        else
        {
            DisableOptions();
        }
    }

    public void ChooseOption(int optionIndex)
    {
      DialogueOption chosenOption = dialogueLines[currentLineIndex].options[optionIndex];
        currentLineIndex = chosenOption.nextLineIndex;
        DisplayDialogueLine(dialogueLines[currentLineIndex]);
    }


    private void EnableOptions(DialogueOption[] options)
    {
      for (int i = 0; i < optionButtons.Length; i++)
      {
        if (i < options.Length)
        {
          int optionIndex = i; //Capture the index for the button click event
          optionButtons[i].gameObject.SetActive(true);
          optionButtons[i].GetComponentInChildren<TextMeshProUGUI>().text = options[i].text;
          optionButtons[i].onClick.RemoveAllListeners(); //Important: Clear existing listeners!
          optionButtons[i].onClick.AddListener(() => ChooseOption(optionIndex)); //Assign a new listener.
        }
        else
        {
          optionButtons[i].gameObject.SetActive(false); //Hide unused buttons.
        }
      }
    }

    private void DisableOptions()
    {
      foreach(Button button in optionButtons)
      {
        button.gameObject.SetActive(false);
      }
    }

    private void EndDialogue()
    {
        dialoguePanel.SetActive(false);
    }
}

Step 4: Connect the UI Elements. In the Unity Editor, create a new empty GameObject. Attach the DialogueManager script to it. Drag and drop the TextMeshProUGUI objects (speaker name and dialogue text), the Panel (dialoguePanel), and the buttons into the corresponding fields in the Inspector. You’ll need to create buttons beforehand, similar to how you created the text element. Attach them to the panel.

Step 5: Populate the dialogueLines Array. This is where you define your dialogue. Create some DialogueLine objects in the Inspector and fill in the text, speaker name, and options. This part can be tedious. Consider loading the dialogue from a file (JSON or XML) for larger conversations.

Triggering the Dialogue

The final piece: how do we start the dialogue?

Step 1: Create an Interaction Script. This script will detect when the player interacts with an object.

Step 2: Implement a Simple Trigger. Use OnTriggerEnter to detect when the player enters a trigger zone.

using UnityEngine;

public class DialogueTrigger : MonoBehaviour
{
    public DialogueManager dialogueManager;

    private void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Player")) // Make sure your player has a "Player" tag
        {
            dialogueManager.StartDialogue();
        }
    }
}

Step 3: Attach the Trigger Script. Attach the DialogueTrigger script to an object in your scene (e.g., an NPC). Add a Collider and set it to Is Trigger. Drag your DialogueManager GameObject into the dialogueManager field in the Inspector.

Common Pitfall: Forget to tag your player object with the “Player” tag. This is a classic mistake that will prevent the dialogue from triggering.

Challenges and Expanding the System

Here’s where things get interesting. You’ve built a basic system. Now, how do you make it better?

Challenge: Long text overflowing the text box.
- Solution: Implement a text scrolling or pagination system. Consider using coroutines to display the text character by character for a more engaging effect.
Challenge: Managing complex branching dialogues.
- Solution: Use a visual scripting tool like Fungus or create a custom dialogue graph editor. This will make it easier to visualize and manage complex conversations.
Challenge: Localizing the dialogue into multiple languages.
- Solution: Use Unity’s localization package or a third-party solution like I2 Localization. Store your dialogue text in separate files for each language.
Value: Think about how the game world will react to the choices the player will make within the dialogue UI. This will add to the immersiveness of your game.

By embracing TextMeshPro and carefully crafting your dialogue system, you can create engaging and memorable conversations that elevate your game from good to unforgettable. Now go forth and create compelling stories!