颜色渐变如何工作？

Question

I'm trying to implement below picture in my code but it doesn't work. It only shows red color on all sides. I'm using line renderer and color gradient.

 void Start()
{
    lineGeneratorPrefab = new GameObject();

    DrawLine();
}




private void DrawLine()
{
    GameObject myLine = new GameObject();
    myLine.transform.position = start;
    myLine.AddComponent<LineRenderer>();
    lr = myLine.GetComponent<LineRenderer>();
    lr.material = new Material(Shader.Find("Sprites/Default"));     
    lr.positionCount = 4;
    lr.SetPosition(0, new Vector3(-2, 0, 0));
    lr.SetPosition(1, new Vector3(2, 0, 0));
    lr.SetPosition(2, new Vector3(2, -2, 0));
    lr.SetPosition(3, new Vector3(-2, -2, 0));
    lr.loop = true;


    Gradient gradient = new Gradient();
    gradient.SetKeys(
        new GradientColorKey[]
        {
            new GradientColorKey(Color.red, 0.25f),
            new GradientColorKey(Color.blue, 0.25f),
            new GradientColorKey(Color.green, 0.25f),
            new GradientColorKey(Color.yellow, 0.25f)
        },
            new GradientAlphaKey[] { new GradientAlphaKey(1.0f, 0.0f) }
        );
    lr.colorGradient = gradient;

}

Answer 1

The 2nd parameter of GradientColorKey is the index between [0,1],

so you may modify the GradientColorKey array like:

new GradientColorKey[]
    {
        new GradientColorKey(Color.red, 0.00f),
        new GradientColorKey(Color.red, 0.24f),
        new GradientColorKey(Color.blue, 0.25f),
        new GradientColorKey(Color.blue, 0.49f),
        new GradientColorKey(Color.green, 0.50f),
        new GradientColorKey(Color.green, 0.74f),
        new GradientColorKey(Color.yellow, 0.75f),
        new GradientColorKey(Color.yellow, 1.00f)
    }