How to change linerenderer color at runtime?

Question

The default color now is mixed of colors with the default material :

I want that at runtime or before running the game if i set the mode to None set the whole linerenderer in red color :

I tried this but this coloring the linerenderer in white even if i set the color property to red :

IEnumerator SelectAnimation(AnimationType animType)
    {
        switch (animType)
        {
            case AnimationType.SingleColorMorph:
                yield return RandomSingleColorMorphing(myLineRenderer, morphTime);
                break;
            case AnimationType.MultiColorMorph:
                yield return RandomMultiColorMorphing(myLineRenderer, morphTime);
                break;
            case AnimationType.Shuffle:
                yield return ShuffleGradient(myLineRenderer, .5f);
                break;
            case AnimationType.Shift:
                yield return AnimateLoop(myLineRenderer);
                break;
            default:
                yield return ggg(Color.red);
                break;
        }
    }

    private Color ggg(Color color)
    {
        Material whiteDiffuseMat = new Material(Shader.Find("Unlit/Texture"));
        whiteDiffuseMat.color = Color.red;
        myLineRenderer.material = whiteDiffuseMat;
        return color;
    }

I also tried inside the method ggg to set myLineRenderer startcolor and endcolor to red without changing the material but it didn't change anything.

user_5740243 · Answer

I managed to solve this problem. Here I will explain how you can change the color of a two-point gradient, for example, but it is up to you to add the desired details. First you need to define a gradient with some key-point's, and since the gradient cannot be lerp into another gradient directly, you need to lerp its colors. A main hint is to display the gradient on the line renderer, you need a material that supports it. I used Particle/ Standard Unlit that work's fine.

Ok Here I setup the lineRenderer with a two-point red and blue gradient (for e.g):

    private LineRenderer _lineRenderer;
    void Start()
    {
        _lineRenderer = GetComponent();
        
        // how to create gradient in script?
        var gradient = new Gradient();
        
        gradient.mode = GradientMode.Blend;

        var gradientColorKeys = new GradientColorKey[2]
        {
            new GradientColorKey(Color.red, .2f),
            new GradientColorKey(Color.blue, .8f)
        };
        
        var alphaKeys = new GradientAlphaKey[2]
        {
            new GradientAlphaKey(1f, .2f),
            new GradientAlphaKey(1f, .8f)
        };

        gradient.SetKeys(gradientColorKeys, alphaKeys);
        
        _lineRenderer.colorGradient = gradient;

        // This enumerator changes color within a specified time
        StartCoroutine(MorphToColor(Color.green, Color.magenta, 2f));
    }

I also wrote a color change Enumarator in the same class that lerps the color of two specific points:

    public IEnumerator MorphToColor(Color color1, Color color2, float morphTime = 1f)
    {
        Debug.Log("start morph");
        var c1 = _lineRenderer.colorGradient.Evaluate(.2f);
        var c2 = _lineRenderer.colorGradient.Evaluate(.8f);

        var fade = 0f;

        while (fade <= 1)
        {
            var gradient = new Gradient();
            gradient.mode = GradientMode.Blend;
            var gradientColorKeys = new GradientColorKey[2]
            {
                new GradientColorKey(Color.Lerp(c1, color1, fade), .2f),
                new GradientColorKey(Color.Lerp(c2, color2, fade), .8f)
            };
        
            var alphaKeys = new GradientAlphaKey[2]
            {
                new GradientAlphaKey(1f, .2f),
                new GradientAlphaKey(1f, .8f)
            };
            
            gradient.SetKeys(gradientColorKeys, alphaKeys);
            
            _lineRenderer.colorGradient = gradient;
            
            yield return new WaitForEndOfFrame();

            fade += Time.deltaTime/morphTime;
        }
    }

As you can see, the result will be like this. I hope it be useful.

How to change linerenderer color at runtime?

1 Answers