Unity3D实现红外热成像效果

Unity3D实现红外热成像效果

引用

CSDN

1.

https://blog.csdn.net/zouxin_88/article/details/124181857

在Unity3D中实现红外热成像效果是一个有趣且实用的技术挑战。本文将详细介绍如何通过设置图层、创建相机、使用RenderTexture、编写C#脚本以及创建shader等步骤，实现一个基本的红外热成像效果。

实现步骤

1. 设置图层
   将需要在红外图像中高亮的物体设置到图层PostProcessing。

2. 创建相机CameraHighLight
   新建一个相机CameraHighLight，设置其Culling Mask为PostProcessing，这样在这个相机中只有PostProcessing图层的物体可见。

3. 创建RenderTexture
   新建一个RenderTexture，命名为HightLightRt，将CameraHighLight的Target Texture设为HightLightRt。

4. 创建相机Camera2
   新建一个相机Camera2，这个相机用于显示其他物体。

5. 合并灰度图
   接下来将CameraHighLight和Camera2中画面转化为两张灰度图，再合并成一张图。合并的过程使用OnRenderImage函数，该函数中使用shader的片断着色器处理，取到两张图相同位置的像素后，谁的灰度值高就取谁的亮度。为了突出CameraHighLight的物体，取Camera2中像素时将适当缩小亮度值。

6. 创建C#脚本ThermalVision.cs
   新建C#脚本ThermalVision.cs，将ThermalVision.cs挂载到Camera2。

   using UnityEngine;
   public class ThermalVision : MonoBehaviour
   {
       public bool IsInverse = false;
       public RenderTexture OtherTex;
       private Material material1;
       private Material material2;
       // Creates a private material used to the effect
       void Awake()
       {
           material1 = new Material(Shader.Find("Hidden/Thermal1"));
           material2 = new Material(Shader.Find("Hidden/Thermal2"));
       }
       // Postprocess the image
       void OnRenderImage(RenderTexture source, RenderTexture destination)
       {
           if (IsInverse)
           {
               material1.SetTexture("_OtherTex", OtherTex);
               Graphics.Blit(source, destination, material1);
           }
           else
           {
               material2.SetTexture("_OtherTex", OtherTex);
               Graphics.Blit(source, destination, material2);
           }
       }
   }
   

7. 创建shader
   新建两个shader，分别为Thermal1、Thermal2，一个为白色模式，一个为黑色模式。

   Shader "Hidden/Thermal1" {
       Properties{
           _MainTex("Base (RGB)", 2D) = "white" {}
           _OtherTex("Other (RGB)", 2D) = "white" {}
       }
       SubShader{
           Pass {
               CGPROGRAM
               #pragma vertex vert_img
               #pragma fragment frag
               #include "UnityCG.cginc"
               uniform sampler2D _MainTex;
               uniform sampler2D _OtherTex;
               float4 frag(v2f_img i) : COLOR {
                   fixed4 renderTex = tex2D(_MainTex, i.uv);
                   fixed4 OtherTex = tex2D(_OtherTex, i.uv);
                   fixed gray1 = 0.2125 * renderTex.r + 0.7154 * renderTex.g + renderTex.b;
                   fixed gray2 = 0.2125 * OtherTex.r + 0.7154 * OtherTex.g + OtherTex.b;
                   fixed maxgr = gray1 * 0.1* step(gray2, gray1) + gray2 * step(gray1, gray2);
                   //fixed maxgr = max(gray1, gray2);
                   fixed3 grayColor = float3(maxgr, maxgr, maxgr);
                   float4 result = renderTex;
                   result.rgb = grayColor;
                   return result;
               }
               ENDCG
           }
       }
   }
   

   Shader "Hidden/Thermal2" {
       Properties{
           _MainTex("Base (RGB)", 2D) = "white" {}
           _OtherTex("Other (RGB)", 2D) = "white" {}
       }
       SubShader{
           Pass {
               CGPROGRAM
               #pragma vertex vert_img
               #pragma fragment frag
               #include "UnityCG.cginc"
               uniform sampler2D _MainTex;
               uniform sampler2D _OtherTex;
               float4 frag(v2f_img i) : COLOR {
                   fixed4 renderTex = tex2D(_MainTex, i.uv);
                   fixed4 OtherTex = tex2D(_OtherTex, i.uv);
                   fixed gray1 = 0.2125 * renderTex.r + 0.7154 * renderTex.g + renderTex.b;
                   fixed gray2 = 0.2125 * OtherTex.r + 0.7154 * OtherTex.g + OtherTex.b;
                   fixed maxgr = gray1 * 0.5* step(gray2, gray1) + gray2 * step(gray1, gray2);
                   fixed3 grayColor = float3(maxgr, maxgr, maxgr);
                   float4 result = renderTex;
                   result.rgb = float3(1- grayColor.r, 1 - grayColor.g, 1 - grayColor.b);
                   return result;
               }
               ENDCG
           }
       }
   }
   

最终效果