Unity中解锁图片像素点，动态闭合轨迹检测

介绍
资源下载
搭建
总结

介绍

因为最近在研究Mane天蚕变的游戏完整逻辑，研究了两套方案做解锁图片的功能，这里我先讲一下我的这个图片像素点的方案解锁图片，这个逻辑其实很简单就是利用划线检测是否轨迹点闭合，然后闭合的点在映射到图片的像素中即可，当然这里需要制作一个shader就是主图层和遮罩层，因为遮罩层的图是动态生成的，所以这块你的像素越大则性能消耗越多也就会卡顿，所以根据实际情况去考量项目需求。

资源下载

项目资源

请添加图片描述

搭建

Canvas模式
在这里插入图片描述
相机模式

ImageMask为空物体
LineRenderer为对应组件的物体
GameObject为挂载我自定义脚本的对象
RawImage是我需要挂载Shader材质球的对象，同时也需要将图放上去

代码
UnlockImageWithShader运行脚本

using UnityEngine;
using UnityEngine.UI;public class UnlockImageWithShader : MonoBehaviour
{public RawImage imageToUnlock; // 需要解锁的图片（使用RawImage）public LineRenderer lineRenderer; // 用于绘制曲线的LineRendererpublic Shader unlockShader; // 自定义Shaderprivate Texture2D maskTexture; // 遮罩纹理private Material unlockMaterial; // 使用Shader的材质void Start(){// 初始化遮罩纹理maskTexture = new Texture2D(256, 256); // 根据需要设置分辨率maskTexture.filterMode = FilterMode.Point;maskTexture.wrapMode = TextureWrapMode.Clamp;ClearMaskTexture(); // 初始化为全黑unlockMaterial = new Material(unlockShader);unlockMaterial.SetTexture("_MainTex", imageToUnlock.texture); // 设置主纹理unlockMaterial.SetTexture("_MaskTex", maskTexture); // 设置遮罩纹理imageToUnlock.material = unlockMaterial; // 应用材质到RawImage// 初始化LineRendererlineRenderer.startWidth = 0.05f;lineRenderer.endWidth = 0.05f;lineRenderer.material = new Material(Shader.Find("Sprites/Default"));lineRenderer.positionCount = 0;}void Update(){if (Input.GetMouseButton(0)){// 将鼠标屏幕坐标转换为UV坐标TVector mousePos = GetMouseUVPosition();points = AddPointUV(mousePos.m_uv);linePoints = AddPointWP(mousePos.m_worldPos);lineRenderer.positionCount = points.Length;lineRenderer.SetPositions(System.Array.ConvertAll(linePoints, v => v));}if (Input.GetMouseButtonUp(0)){if (IsClosedCurve(points)){UnlockArea(points);}points = new Vector2[0]; // 清空点数组linePoints = new Vector3[0];lineRenderer.positionCount = 0; // 清空LineRenderer}}private Vector2[] points = new Vector2[0]; // 存储玩家绘制的点private Vector3[] linePoints = new Vector3[0]; // 存储玩家绘制的点Vector2[] AddPointUV(Vector2 point){Vector2[] newPoints = new Vector2[points.Length + 1];points.CopyTo(newPoints, 0);newPoints[points.Length] = point;return newPoints;}Vector3[] AddPointWP(Vector3 point){Vector3[] newPoints = new Vector3[points.Length + 1];linePoints.CopyTo(newPoints, 0);newPoints[points.Length] = point;return newPoints;}bool IsClosedCurve(Vector2[] points){if (points.Length < 3) return false; // 至少需要3个点才能形成闭合曲线float distance = Vector2.Distance(points[0], points[points.Length - 1]);return distance < 0.05f; // 判断起点和终点是否接近（阈值）}void UnlockArea(Vector2[] points){// 将多边形区域填充为白色for (int y = 0; y < maskTexture.height; y++){for (int x = 0; x < maskTexture.width; x++){Vector2 pixelUV = new Vector2((float)x / maskTexture.width, (float)y / maskTexture.height);if (IsPointInPolygon(pixelUV, points)){Color c = new Color(Color.white.r, Color.white.g, Color.white.b, 1);maskTexture.SetPixel(x, y, c); // 设置为白色（解锁）}}}maskTexture.Apply(); // 应用纹理更改byte[] b = maskTexture.EncodeToPNG();System.IO.File.WriteAllBytes(Application.dataPath + "/t1.png", b);Debug.LogError("Mask texture updated."); // 调试日志}bool IsPointInPolygon(Vector2 point, Vector2[] polygon){int intersections = 0;for (int i = 0; i < polygon.Length; i++){Vector2 p1 = polygon[i];Vector2 p2 = polygon[(i + 1) % polygon.Length];if (point.y > Mathf.Min(p1.y, p2.y)){if (point.y <= Mathf.Max(p1.y, p2.y)){if (point.x <= Mathf.Max(p1.x, p2.x)){float xIntersection = (point.y - p1.y) * (p2.x - p1.x) / (p2.y - p1.y) + p1.x;if (p1.x == p2.x || point.x <= xIntersection){intersections++;}}}}}return intersections % 2 != 0; // 奇数交点表示点在多边形内}public class TVector {public Vector2 m_uv;public Vector3 m_worldPos;public TVector(Vector2 uv,Vector3 wp){m_uv = uv;m_worldPos = wp;}}TVector GetMouseUVPosition(){// 将鼠标屏幕坐标转换为UV坐标Vector2 mousePos = Input.mousePosition;// 确保传入的摄像机参数正确bool success = RectTransformUtility.ScreenPointToLocalPointInRectangle(imageToUnlock.rectTransform, mousePos, Camera.main, out Vector2 localPoint);RectTransformUtility.ScreenPointToWorldPointInRectangle(imageToUnlock.rectTransform, mousePos, Camera.main, out Vector3 worldPos);// 将局部坐标转换为 UV 坐标Vector2 uv = Rect.PointToNormalized(imageToUnlock.rectTransform.rect, localPoint);return new  TVector (uv, worldPos);}void ClearMaskTexture(){// 将遮罩纹理初始化为全黑Color[] colors = new Color[maskTexture.width * maskTexture.height];for (int i = 0; i < colors.Length; i++){colors[i] = new Color(Color.black.r, Color.black.g, Color.black.b, 0);}maskTexture.SetPixels(colors);maskTexture.Apply();}
}

UnlockImageShader.Shader

Shader "Custom/UnlockImageShader"
{Properties{_MainTex ("Main Texture", 2D) = "white" {} // 主纹理_MaskTex ("Mask Texture", 2D) = "white" {} // 遮罩纹理}SubShader{Tags { "Queue"="Transparent" "RenderType"="Transparent" }LOD 200Pass{CGPROGRAM#pragma vertex vert#pragma fragment frag#include "UnityCG.cginc"struct appdata{float4 vertex : POSITION;float2 uv : TEXCOORD0;};struct v2f{float2 uv : TEXCOORD0;float4 vertex : SV_POSITION;};sampler2D _MainTex;sampler2D _MaskTex;v2f vert (appdata v){v2f o;o.vertex = UnityObjectToClipPos(v.vertex);o.uv = v.uv;return o;}fixed4 frag (v2f i) : SV_Target{fixed4 mainColor = tex2D(_MainTex, i.uv); // 主纹理颜色fixed4 maskColor = tex2D(_MaskTex, i.uv); // 遮罩纹理颜色// 如果遮罩纹理的 alpha 值大于 0.5，显示主纹理，否则显示黑色return maskColor.a > 0.5 ? mainColor : fixed4(0, 0, 0, 1);}ENDCG}}
}