Unity Openable Classic and Sliding Doors

In this tutorial, I will be showing how to make a classic and a sliding door in Unity.

Classic Door

A classic door is a regular door that is opened by rotating around its hinges.

Steps

To make a regular door in Unity, follow the steps below:

• Create a new script, call it 'SC_DoorScript', remove everything from it then paste the code below:

SC_DoorScript.cs

//Make an empty GameObject and call it "Door"
//Drag and drop your Door model into Scene and rename it to "Body"
//Make sure that the "Door" Object is at the side of the "Body" object (The place where a Door Hinge should be)
//Move the "Body" Object inside "Door"
//Add a Collider (preferably SphereCollider) to "Door" object and make it bigger then the "Body" model
//Assign this script to a "Door" Object (the one with a Trigger Collider)
//Make sure the main Character is tagged "Player"
//Upon walking into trigger area press "F" to open / close the door

using UnityEngine;

public class SC_DoorScript : MonoBehaviour
{
    // Smoothly open a door
    public AnimationCurve openSpeedCurve = new AnimationCurve(new Keyframe[] { new Keyframe(0, 1, 0, 0), new Keyframe(0.8f, 1, 0, 0), new Keyframe(1, 0, 0, 0) }); //Contols the open speed at a specific time (ex. the door opens fast at the start then slows down at the end)
    public float openSpeedMultiplier = 2.0f; //Increasing this value will make the door open faster
    public float doorOpenAngle = 90.0f; //Global door open speed that will multiply the openSpeedCurve

    bool open = false;
    bool enter = false;

    float defaultRotationAngle;
    float currentRotationAngle;
    float openTime = 0;

    void Start()
    {
        defaultRotationAngle = transform.localEulerAngles.y;
        currentRotationAngle = transform.localEulerAngles.y;

        //Set Collider as trigger
        GetComponent<Collider>().isTrigger = true;
    }

    // Main function
    void Update()
    {
        if (openTime < 1)
        {
            openTime += Time.deltaTime * openSpeedMultiplier * openSpeedCurve.Evaluate(openTime);
        }
        transform.localEulerAngles = new Vector3(transform.localEulerAngles.x, Mathf.LerpAngle(currentRotationAngle, defaultRotationAngle + (open ? doorOpenAngle : 0), openTime), transform.localEulerAngles.z);

        if (Input.GetKeyDown(KeyCode.F) && enter)
        {
            open = !open;
            currentRotationAngle = transform.localEulerAngles.y;
            openTime = 0;
        }
    }

    // Display a simple info message when player is inside the trigger area (This is for testing purposes only so you can remove it)
    void OnGUI()
    {
        if (enter)
        {
            GUI.Label(new Rect(Screen.width / 2 - 75, Screen.height - 100, 155, 30), "Press 'F' to " + (open ? "close" : "open") + " the door");
        }
    }
    //

    // Activate the Main function when Player enter the trigger area
    void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Player"))
        {
            enter = true;
        }
    }

    // Deactivate the Main function when Player exit the trigger area
    void OnTriggerExit(Collider other)
    {
        if (other.CompareTag("Player"))
        {
            enter = false;
        }
    }
}

• Drag & drop your door model into the Scene view (or create a new Cube and scale it to resemble a door)
• Create a new GameObject (GameObject -> Create Empty) and name it "Door"
• Move the "Door" object to the position where the door hinge should be

• Attach a SphereCollider component to the "Door" object and change its radius so it's larger than a door (this will be the area from where the player will be able to open the door)
• Move your door model inside the "Door" object
• Make sure your player is tagged as "Player"
• Upon walking into the trigger area you should be able to open/close the door by pressing 'F'.

Sliding Door

A sliding door is a door that opens by sliding into a specific direction (ex. up, down, left, or right) and is often used in Sci-fi levels.

Steps

To make a sliding door in Unity, follow the steps below:

• Create a new script, call it 'SC_SlidingDoor', remove everything from it then paste the code below:

SC_SlidingDoor.cs

//Make an empty GameObject and call it "SlidingDoor"
//Drag and drop your Door model into Scene and rename it to "Body"
//Move the "Body" Object inside "SlidingDoor"
//Add a Collider (preferably SphereCollider) to "SlidingDoor" Object and make it bigger then the "Body" model
//Assign this script to a "SlidingDoor" Object (the one with a Trigger Collider)
//Make sure the main Character is tagged "Player"
//Upon walking into trigger area the door should Open automatically

using UnityEngine;

public class SC_SlidingDoor : MonoBehaviour
{
    // Sliding door
    public AnimationCurve openSpeedCurve = new AnimationCurve(new Keyframe[] { new Keyframe(0, 1, 0, 0), new Keyframe(0.8f, 1, 0, 0), new Keyframe(1, 0, 0, 0) }); //Contols the open speed at a specific time (ex. the door opens fast at the start then slows down at the end)
    public enum OpenDirection { x, y, z }
    public OpenDirection direction = OpenDirection.y;
    public float openDistance = 3f; //How far should door slide (change direction by entering either a positive or a negative value)
    public float openSpeedMultiplier = 2.0f; //Increasing this value will make the door open faster
    public Transform doorBody; //Door body Transform

    bool open = false;

    Vector3 defaultDoorPosition;
    Vector3 currentDoorPosition;
    float openTime = 0;

    void Start()
    {
        if (doorBody)
        {
            defaultDoorPosition = doorBody.localPosition;
        }

        //Set Collider as trigger
        GetComponent<Collider>().isTrigger = true;
    }

    // Main function
    void Update()
    {
        if (!doorBody)
            return;

        if (openTime < 1)
        {
            openTime += Time.deltaTime * openSpeedMultiplier * openSpeedCurve.Evaluate(openTime);
        }

        if (direction == OpenDirection.x)
        {
            doorBody.localPosition = new Vector3(Mathf.Lerp(currentDoorPosition.x, defaultDoorPosition.x + (open ? openDistance : 0), openTime), doorBody.localPosition.y, doorBody.localPosition.z);
        }
        else if (direction == OpenDirection.y)
        {
            doorBody.localPosition = new Vector3(doorBody.localPosition.x, Mathf.Lerp(currentDoorPosition.y, defaultDoorPosition.y + (open ? openDistance : 0), openTime), doorBody.localPosition.z);
        }
        else if (direction == OpenDirection.z)
        {
            doorBody.localPosition = new Vector3(doorBody.localPosition.x, doorBody.localPosition.y, Mathf.Lerp(currentDoorPosition.z, defaultDoorPosition.z + (open ? openDistance : 0), openTime));
        }
    }

    // Activate the Main function when Player enter the trigger area
    void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Player"))
        {
            open = true;
            currentDoorPosition = doorBody.localPosition;
            openTime = 0;
        }
    }

    // Deactivate the Main function when Player exit the trigger area
    void OnTriggerExit(Collider other)
    {
        if (other.CompareTag("Player"))
        {
            open = false;
            currentDoorPosition = doorBody.localPosition;
            openTime = 0;
        }
    }
}

• Drag & drop your door model into the Scene view (or create a new Cube and scale it to resemble a door)
• Create a new GameObject (GameObject -> Create Empty) and name it "SlidingDoor"
• Move the "SlidingDoor" object to the center position of your door model
• Attach a SphereCollider component to the "SlidingDoor" object and change its radius so it's larger than a door (this will be the area that will trigger the open event)
• Move your door model inside the "SlidingDoor" object
• Make sure your player is tagged as "Player"
• Upon walking into the trigger area the door should open automatically and then close once the player leaves the trigger area.