How do I change the model's expressions during gameplay?

CBeam

I have checked the live2D Manual at "Cubism SDK > platform > Unity", and I haven't found a clear way to change a model's expressions or animations through code.

What I'm trying to do is a function I can call, for example "ShowHappyCharacter();" and "ShowSadCharacter();" that I can use to change the expressions during gameplay.

naotaro

Hi, CBeam .

I think change of model's expressions is a code only to SampleApp1 project of Live2D Unity SDK.
It has change of model's expressions in LAppModel.cs .

[SampleApp1/Assets/Scripts/sample/LAppModel.cs]

public void Init(String modelJson)
{
	・
	・
	// Expression .json Load
	if (modelSetting.GetExpressionNum() != 0)
	{
		var len = modelSetting.GetExpressionNum();
		for (int i = 0; i < len; i++)
		{
			loadExpression(modelSetting.GetExpressionName(i), modelHomeDir + modelSetting.GetExpressionFile(i));
		}
	}
	・
	・
}

public void Update()
{
	・
	・
	// Expression parameter update
	if (expressionManager != null) expressionManager.updateParam(live2DModel);
	・
	・
	
	// parameter update
	live2DModel.update();
}

Good luck !

Wai

I really wish I could help you with this CBeam, but I know nothing about Unity. I hope naotaro answered your question. He/She is awesome. Good luck!!

CBeam

Ah, it's ok Wai, thank you though.

Naotaro, I think I have not explained my situation properly, but I am thankful for your response. What I want to do is to have the live2d model's emotion to change during gameplay, so I think that a function that uses "Input" during the "Update()" is required, but I don't know which.

For example, when I press "A", the emotion changes to "Confident Smile", and when I press "B", it changes to "Laughing".

Finding a function that changes the expression during "Update()" depending on a variable would also solve my issue.

naotaro

My Acquaintance is creating a simple script . Please wait a little .

yasu.o@live2d

Hi, CBeam.

You can switch facial expression by changing /sample/Simple/simpleModel.cs of Live2D SDK like below:

using UnityEngine;
using live2d;
using live2d.framework; //

[ExecuteInEditMode]
public class SimpleModel : MonoBehaviour 
{
	public TextAsset mocFile ;
	public Texture2D[] textureFiles ;
	
	private Live2DModelUnity live2DModel;
    private Matrix4x4 live2DCanvasPos;

    // expression
    public TextAsset expJsonA, expJsonB; //Please Drag & Drop .exp.json to expJsonA and expJsonB in the Inspector of the Unity Editor.
    AMotion expressionMotionA, expressionMotionB;
    MotionQueueManager expressionMgr;
	
	void Start ()
    {
        if (live2DModel != null) return;
        Live2D.init();

        live2DModel = Live2DModelUnity.loadModel(mocFile.bytes);
        for (int i = 0; i < textureFiles.Length; i++)
        {
            live2DModel.setTexture(i, textureFiles[i]);
        }

        float modelWidth = live2DModel.getCanvasWidth();
        live2DCanvasPos = Matrix4x4.Ortho(0, modelWidth, modelWidth, 0, -50.0f, 50.0f);

        // load .exp.json
        expressionMotionA = L2DExpressionMotion.loadJson(expJsonA.bytes);
        expressionMotionB = L2DExpressionMotion.loadJson(expJsonB.bytes);

        expressionMgr = new MotionQueueManager();
    }
	
    void Update()
    {
        if (live2DModel == null) return;
        live2DModel.setMatrix(transform.localToWorldMatrix * live2DCanvasPos);

        if (!Application.isPlaying)
        {
            live2DModel.update();
            return;
        }
        

        // Change Expression.
        if (Input.GetKeyDown(KeyCode.A))
        {// pressed "A" key.
            expressionMgr.startMotion(expressionMotionA);
        }
        else if (Input.GetKeyDown(KeyCode.B))
        {// pressed "B" key.
            expressionMgr.startMotion(expressionMotionB);
        }

        // update change of expression to Live2D model.
        expressionMgr.updateParam(live2DModel);
        
        live2DModel.update();
    }
	
	void OnRenderObject()
	{
        if (live2DModel == null) return;
        live2DModel.draw();
    }
}

Add L2DExpressionMotion.cs to the project because L2DExpressionMotion is used to load exp.json.
L2DExpressionMotion is in /framework folder of Live2D SDK.

I hope this will answer your question.

CBeam

I have followed your instructions and used expression 6 and 8. It works!

Thank you very much naotaro for your help and y_a_s_ for the code!