81 lines
2.7 KiB
C#
81 lines
2.7 KiB
C#
using UnityEngine;
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using System.Collections;
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[ExecuteInEditMode]
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public class Polygon : MonoBehaviour
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{
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public Material mat; //绑定材质
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Vector3[] worldPos; //存储获取的3D坐标
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Vector4[] screenPos; //存储待绘制的多边形顶点屏幕坐标
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int maxPointNum = 99; //多边形顶点总数
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public int currentpointNum = 0; //当前已经获得的顶点数
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public int pointNum2Shader = 0; //传递顶点数量给shader
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public bool InSelection = true; //是否处于顶点获取过程
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void Start()
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{
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worldPos = new Vector3[maxPointNum];
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screenPos = new Vector4[maxPointNum];
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}
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void Update()
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{
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mat.SetVectorArray("Value", screenPos); //传递顶点屏幕位置信息给shader
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mat.SetInt("PointNum", pointNum2Shader); //传递顶点数量给shader
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//使用摄像机发射一条射线，以获取要选择的3D位置
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Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
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RaycastHit hit;
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if (Physics.Raycast(ray, out hit, 100))
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{
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Debug.DrawLine(ray.origin, hit.point);
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}
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//利用鼠标点击来获取位置信息
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if (Input.GetMouseButtonDown(0) && InSelection)
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{
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if (currentpointNum < maxPointNum)
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{
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currentpointNum++;
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pointNum2Shader++;
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worldPos[currentpointNum - 1] = hit.point;
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Vector3 v3 = Camera.main.WorldToScreenPoint(worldPos[currentpointNum - 1]);
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screenPos[currentpointNum - 1] = new Vector4(v3.x, Screen.height - v3.y, v3.z, 0);
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//Debug.Log($"screenPos=={screenPos[currentpointNum - 1]}");
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//Debug.Log($"currentpointNum=={currentpointNum}");
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}
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else
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{
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InSelection = false;
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}
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}
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//实时更新已选择的3D点的屏幕位置
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for (int i = 0; i < maxPointNum; i++)
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{
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Vector3 v3 = Camera.main.WorldToScreenPoint(worldPos[i]);
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screenPos[i] = new Vector4(v3.x, Screen.height - v3.y, v3.z, 0);
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}
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//检测是否有3D点移动到了摄像机后面，如果有，则停止绘制
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for (int i = 0; i < currentpointNum; i++)
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{
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if (Vector3.Dot(worldPos[i] - Camera.main.transform.position, Camera.main.transform.forward) <= 0)
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{
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pointNum2Shader = 0;
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break;
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}
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pointNum2Shader = currentpointNum;
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}
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}
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//抓取当前的渲染图像进行处理
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void OnRenderImage(RenderTexture src, RenderTexture dest)
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{
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Graphics.Blit(src, dest, mat);
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}
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}
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