浏览一下 GitHub ，找了找UGUI开源的东西 https://github.com/WestHillApps/uGUI-Effect-Tool

发现了 uGuiEffectTool （包括Blend【意义不大】 和 渐变）

这个是原始图片

Blend的效果：

Blend的代码：

using UnityEngine;
using System.Collections.Generic;
using UnityEngine.UI;

namespace UiEffect
{
    [AddComponentMenu ("UI/Effects/Blend Color")]
    [RequireComponent (typeof (Graphic))]
    public class BlendColor : BaseVertexEffect
    {
        public enum BLEND_MODE
        {
            Multiply,
            Additive,
            Subtractive,
            Override,
        }

        public BLEND_MODE blendMode = BLEND_MODE.Multiply;
        public Color color = Color.grey;

        Graphic graphic;

        public override void ModifyVertices (List vList)
        {
            if (IsActive () == false || vList == null || vList.Count == 0) {
                return;
            }

            UIVertex tempVertex = vList[0];
            for (int i = 0; i < vList.Count; i++) {
                tempVertex = vList[i];
                byte orgAlpha = tempVertex.color.a;
                switch (blendMode) {
                    case BLEND_MODE.Multiply:
                        tempVertex.color *= color;
                        break;
                    case BLEND_MODE.Additive:
                        tempVertex.color += color;
                        break;
                    case BLEND_MODE.Subtractive:
                        tempVertex.color -= color;
                        break;
                    case BLEND_MODE.Override:
                        tempVertex.color = color;
                        break;
                }
                tempVertex.color.a = orgAlpha;
                vList[i] = tempVertex;
            }
        }

        /// 

        /// Refresh Blend Color on playing.
        /// 
        public void Refresh ()
        {
            if (graphic == null) {
                graphic = GetComponent ();
            }
            if (graphic != null) {
                graphic.SetVerticesDirty ();
            }
        }
    }
}

Gradient效果：

Gradient代码：

using UnityEngine;
using System.Collections.Generic;
using UnityEngine.UI;

namespace UiEffect
{
    [AddComponentMenu ("UI/Effects/Gradient Color")]
    [RequireComponent (typeof (Graphic))]
    public class GradientColor : BaseVertexEffect
    {
        public enum DIRECTION
        {
            Vertical,
            Horizontal,
            Both,
        }

        public DIRECTION direction = DIRECTION.Both;
        public Color colorTop = Color.white;
        public Color colorBottom = Color.black;
        public Color colorLeft = Color.red;
        public Color colorRight = Color.blue;

        Graphic graphic;

        public override void ModifyVertices (List vList)
        {
            if (IsActive () == false || vList == null || vList.Count == 0) {
                return;
            }

            float topX = 0f, topY = 0f, bottomX = 0f, bottomY = 0f;
            foreach (var vertex in vList) {
                topX = Mathf.Max (topX, vertex.position.x);
                topY = Mathf.Max (topY, vertex.position.y);
                bottomX = Mathf.Min (bottomX, vertex.position.x);
                bottomY = Mathf.Min (bottomY, vertex.position.y);
            }
            float width = topX - bottomX;
            float height = topY - bottomY;

            UIVertex tempVertex = vList[0];
            for (int i = 0; i < vList.Count; i++) {
                tempVertex = vList[i];
                byte orgAlpha = tempVertex.color.a;
                Color colorOrg = tempVertex.color;
                Color colorV = Color.Lerp (colorBottom, colorTop, (tempVertex.position.y - bottomY) / height);
                Color colorH = Color.Lerp (colorLeft, colorRight, (tempVertex.position.x - bottomX) / width);
                switch (direction) {
                    case DIRECTION.Both:
                        tempVertex.color = colorOrg * colorV * colorH;
                        break;
                    case DIRECTION.Vertical:
                        tempVertex.color = colorOrg * colorV;
                        break;
                    case DIRECTION.Horizontal:
                        tempVertex.color = colorOrg * colorH;
                        break;
                }
                tempVertex.color.a = orgAlpha;
                vList[i] = tempVertex;
            }
        }

        /// 

        /// Refresh Gradient Color on playing.
        /// 
        public void Refresh ()
        {
            if (graphic == null) {
                graphic = GetComponent ();
            }
            if (graphic != null) {
                graphic.SetVerticesDirty ();
            }
        }
    }
}