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Unity做简单的有限元分析效果

一、获取Mesh顶点位置，并在顶点生成用于控制的小球

ChangMesh.cs（pointsFather是小球的父物体，随便找个空物体就行。）

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
 
public class ChangeMesh : MonoBehaviour
{
    public GameObject pointsFather;
    private Mesh mesh;
    private GameObject newPoint;
    private Vector3[] vertices;
 
    // Start is called before the first frame update
    void Start()
    {
        pointsFather.transform.position = this.transform.position;
        mesh = this.GetComponent<MeshFilter>().mesh;
        vertices = new Vector3[mesh.vertices.Length];
        CreatMeshPoint();
    }
 
    private void CreatMeshPoint()
    {
        for (int i = 0; i < mesh.vertices.Length; i++)
        {
            vertices[i] = mesh.vertices[i];
        }
        for (int i = 0; i < mesh.vertices.Length; i++)
        {
            GameObject creatPoint = GameObject.CreatePrimitive(PrimitiveType.Sphere);
            creatPoint.transform.localPosition = vertices[i];
            creatPoint.transform.name = "EditorPoint" + i.ToString();
            creatPoint.transform.localScale = new Vector3(0.01f, 0.01f, 0.01f);
            creatPoint.transform.parent = pointsFather.transform;
            float distance = Vector3.Distance(creatPoint.transform.localPosition, Vector3.zero);
        }
    }
 
    private void MovePoint()
    {
        for(int i=0;i<mesh.vertices.Length;i++)
        {
            newPoint = GameObject.Find("EditorPoint" + i.ToString());
            if(newPoint.transform.position!=vertices[i])
            {
                vertices[i] = newPoint.transform.position;
            }
        }
        mesh.vertices = vertices;
        mesh.RecalculateTangents();
        mesh.RecalculateNormals();
    }
 
    // Update is called once per frame
    void Update()
    {
        MovePoint();
    }
 
}

二、编写Shader

ColorChange.shader

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Shader "Custom/ColorChange"
{
    Properties
    {
        _Color("Color",Color) = (1,1,1,1)
        _Height("Normal",Float) = 1
        _Ambient("Ambient",Float) = 5
        _Specular("Specular",Float) = 20
    }
    SubShader
    {
        Pass
        {
           CGPROGRAM
 
              fixed4 _Color; 
              float _Height;
              float _Ambient;
              float _Specular;
              #pragma vertex vert
              #pragma fragment frag
              #include "UnityCG.cginc"
 
              struct a2v {/*模型到顶点*/
                  fixed4 vertex : POSITION;
                  fixed3 normal : NORMAL;
              };
 
              struct v2f {/*顶点到面*/
                  fixed4 pos : SV_POSITION;
                  fixed3 worldNormal : TEXCOORD0;
                  fixed3 worldPos : TEXCOORD1;
              };
 
              v2f vert(a2v v)/*顶点函数*/
              {
                  //v.vertex.xyz += _Height * v.normal;/**/
                  v2f o;
                  v2f old;/**/
                  o.pos = UnityObjectToClipPos(v.vertex);/*重要的函数UnityObjectToClipPos，转换坐标*/
                  o.worldNormal = UnityObjectToWorldNormal(v.normal);/*重要的函数UnityObjectToWorldNormal，转换坐标*/
                  o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
                  return o;
              }
 
              fixed4 frag(v2f i) :SV_Target/*片元函数*/
              {
                  //fixed3 l = normalize(_WorldSpaceLightPos0.xyz);
                  //float diff = dot(i.worldNormal, 1);
                  //diff = diff < 0 ? 0 : diff;
                   
                  fixed3 zero = fixed3(0,0,0);
                  float distance = sqrt(pow(i.worldPos.x - zero.x, 2) + pow(i.worldPos.y - zero.y, 2) + pow(i.worldPos.z - zero.z, 2));
                  float standardV = 0.5; 
                  //fixed3 cameraPos = _WorldSpaceCameraPos.xyz;
                  //fixed3 v = normalize(i.worldPos- cameraPos);
                  //fixed4 position = fixed4(v * 2, 1);
 
 
                  fixed4 position0 = fixed4(1, 1, 0, 1);
                  //fixed4 position1 = fixed4(1, 0, 0, 1);
                  //fixed4 position2 = fixed4(1, 0.647, 0, 1);
                  //fixed4 position3 = fixed4(1, 1, 0.5, 1);
                  //fixed4 position4 = fixed4(0, 1, 0, 1);
                  //fixed4 position5 = fixed4(0, 0.675, 1, 1);
                  //fixed4 position6 = fixed4(0, 0, 1, 1);
                  //fixed4 position7 = fixed4(0.545, 0, 1, 1);
 
                  fixed4 position1 = fixed4(1, 0.9, 0, 1);
                  fixed4 position2 = fixed4(1, 0.8, 0, 1);
                  fixed4 position3 = fixed4(1, 0.7, 0, 1);
                  fixed4 position4 = fixed4(1, 0.6, 0, 1);
                  fixed4 position5 = fixed4(1, 0.5, 0, 1);
                  fixed4 position6 = fixed4(1, 0.4, 0, 1);
                  fixed4 position7 = fixed4(1, 0.3, 0, 1);
                  fixed4 position8 = fixed4(1, 0.2, 0, 1);
                  fixed4 position9 = fixed4(1, 0.1, 0, 1);
                  fixed4 position10 = fixed4(1, 0, 0, 1);
                  fixed4 position11 = fixed4(0, 1, 0, 1);
 
 
                  if (distance-standardV > 0.01&&distance - standardV < 0.02)
                  {
                      return position1;
                  }
                  else if(distance - standardV > 0.02&&distance - standardV < 0.03)
                  {
                      return position2;
                  }
                  else if (distance - standardV > 0.03&&distance - standardV < 0.04)
                  {
                      return position3;
                  }
                  else if (distance - standardV > 0.04&&distance - standardV < 0.05)
                  {
                      return position4;
                  }
                  else if (distance - standardV > 0.05&&distance - standardV < 0.06)
                  {
                      return position5;
                  }
                  else if (distance - standardV > 0.06&&distance - standardV < 0.07)
                  {
                      return position6;
                  }
                  else if (distance - standardV > 0.07&&distance - standardV < 0.08)
                  {
                      return position7;
                  }
                  else if (distance - standardV > 0.08&&distance - standardV < 0.09)
                  {
                      return position8;
                  }
                  else if (distance - standardV > 0.09&&distance - standardV < 0.010)
                  {
                      return position9;
                  }
                  else if (distance - standardV >= 0.010)
                  {
                      return position10;
                  }
                  else if (distance - standardV < -0.01)
                  {
                      return position11;
                  }
                  else
                  {
                      return position0;
                  }
 
                  //return position;
 
              }
          ENDCG
        }
    }
    FallBack "Diffuse"
}