先上效果图
Paste_Image.png
新建一个C#脚本和一个shader脚本，再新建一个材质，将shader挂在材质球上，材质球挂在Plane平面上，C#脚本也挂在Plane平面上
Paste_Image.png
新建C#脚本
using UnityEngine;
using System.Collections;
[ExecuteInEditMode]
public class Mirror : MonoBehaviour
{
public bool m_DisablePixelLights = true;
public int m_TextureSize = 256;
public float m_ClipPlaneOffset = 0.07f;
public bool m_IsFlatMirror = true;
public LayerMask m_ReflectLayers = -1;
private Hashtable m_ReflectionCameras = new Hashtable();
private RenderTexture m_ReflectionTexture = null;
private int m_OldReflectionTextureSize = 0;
private static bool s_InsideRendering = false;
public void OnWillRenderObject()
{
if( !enabled || !GetComponent() || !GetComponent().sharedMaterial || !GetComponent().enabled )
return;
Camera cam = Camera.current;
if( !cam )
return;
if( s_InsideRendering )
return;
s_InsideRendering = true;
Camera reflectionCamera;
CreateMirrorObjects( cam, out reflectionCamera );
Vector3 pos = transform.position;
Vector3 normal;
if(m_IsFlatMirror){
normal = transform.up;
}
else{
normal= transform.position - cam.transform.position ;
normal.Normalize();
}
int oldPixelLightCount = QualitySettings.pixelLightCount;
if( m_DisablePixelLights )
QualitySettings.pixelLightCount = 0;
UpdateCameraModes( cam, reflectionCamera );
float d = -Vector3.Dot (normal, pos) - m_ClipPlaneOffset;
Vector4 reflectionPlane = new Vector4 (normal.x, normal.y, normal.z, d);
Matrix4x4 reflection = Matrix4x4.zero;
CalculateReflectionMatrix (ref reflection, reflectionPlane);
Vector3 oldpos = cam.transform.position;
Vector3 newpos = reflection.MultiplyPoint( oldpos );
reflectionCamera.worldToCameraMatrix = cam.worldToCameraMatrix * reflection;
Vector4 clipPlane = CameraSpacePlane( reflectionCamera, pos, normal, 1.0f );
Matrix4x4 projection = cam.projectionMatrix;
CalculateObliqueMatrix (ref projection, clipPlane);
reflectionCamera.projectionMatrix = projection;
reflectionCamera.cullingMask = ~(1<<4) & m_ReflectLayers.value;
reflectionCamera.targetTexture = m_ReflectionTexture;
GL.SetRevertBackfacing (true);
reflectionCamera.transform.position = newpos;
Vector3 euler = cam.transform.eulerAngles;
reflectionCamera.transform.eulerAngles = new Vector3(0, euler.y, euler.z);
reflectionCamera.Render();
reflectionCamera.transform.position = oldpos;
GL.SetRevertBackfacing (false);
Material[] materials = GetComponent().sharedMaterials;
foreach( Material mat in materials ) {
if( mat.HasProperty("_Ref") )
mat.SetTexture( "_Ref", m_ReflectionTexture );
}
if( m_DisablePixelLights )
QualitySettings.pixelLightCount = oldPixelLightCount;
s_InsideRendering = false;
}
void OnDisable()
{
if( m_ReflectionTexture ) {
DestroyImmediate( m_ReflectionTexture );
m_ReflectionTexture = null;
}
foreach( DictionaryEntry kvp in m_ReflectionCameras )
DestroyImmediate( ((Camera)kvp.Value).gameObject );
m_ReflectionCameras.Clear();
}
private void UpdateCameraModes( Camera src, Camera dest )
{
if( dest == null )
return;
dest.clearFlags = src.clearFlags;
dest.backgroundColor = src.backgroundColor;
if( src.clearFlags == CameraClearFlags.Skybox )
{
Skybox sky = src.GetComponent(typeof(Skybox)) as Skybox;
Skybox mysky = dest.GetComponent(typeof(Skybox)) as Skybox;
if( !sky || !sky.material )
{
mysky.enabled = false;
}
else
{
mysky.enabled = true;
mysky.material = sky.material;
}
}
dest.farClipPlane = src.farClipPlane;
dest.nearClipPlane = src.nearClipPlane;
dest.orthographic = src.orthographic;
dest.fieldOfView = src.fieldOfView;
dest.aspect = src.aspect;
dest.orthographicSize = src.orthographicSize;
dest.renderingPath = src.renderingPath;
}
private void CreateMirrorObjects( Camera currentCamera, out Camera reflectionCamera )
{
reflectionCamera = null;
if( !m_ReflectionTexture || m_OldReflectionTextureSize != m_TextureSize )
{
if( m_ReflectionTexture )
DestroyImmediate( m_ReflectionTexture );
m_ReflectionTexture = new RenderTexture( m_TextureSize, m_TextureSize, 16 );
m_ReflectionTexture.name = "__MirrorReflection" + GetInstanceID();
m_ReflectionTexture.isPowerOfTwo = true;
m_ReflectionTexture.hideFlags = HideFlags.DontSave;
m_OldReflectionTextureSize = m_TextureSize;
}
reflectionCamera = m_ReflectionCameras[currentCamera] as Camera;
if( !reflectionCamera )
{
GameObject go = new GameObject( "Mirror Refl Camera id" + GetInstanceID() + " for " + currentCamera.GetInstanceID(), typeof(Camera), typeof(Skybox) );
reflectionCamera = go.GetComponent();
reflectionCamera.enabled = false;
reflectionCamera.transform.position = transform.position;
reflectionCamera.transform.rotation = transform.rotation;
reflectionCamera.gameObject.AddComponent();
go.hideFlags = HideFlags.HideAndDontSave;
m_ReflectionCameras[currentCamera] = reflectionCamera;
}
}
private static float sgn(float a)
{
if (a > 0.0f) return 1.0f;
if (a < 0.0f) return -1.0f;
return 0.0f;
}
private Vector4 CameraSpacePlane (Camera cam, Vector3 pos, Vector3 normal, float sideSign)
{
Vector3 offsetPos = pos + normal * m_ClipPlaneOffset;
Matrix4x4 m = cam.worldToCameraMatrix;
Vector3 cpos = m.MultiplyPoint( offsetPos );
Vector3 cnormal = m.MultiplyVector( normal ).normalized * sideSign;
return new Vector4( cnormal.x, cnormal.y, cnormal.z, -Vector3.Dot(cpos,cnormal) );
}
private static void CalculateObliqueMatrix (ref Matrix4x4 projection, Vector4 clipPlane)
{
Vector4 q = projection.inverse * new Vector4(
sgn(clipPlane.x),
sgn(clipPlane.y),
1.0f,
1.0f
);
Vector4 c = clipPlane * (2.0F / (Vector4.Dot (clipPlane, q)));
projection[2] = c.x - projection[3];
projection[6] = c.y - projection[7];
projection[10] = c.z - projection[11];
projection[14] = c.w - projection[15];
}
private static void CalculateReflectionMatrix (ref Matrix4x4 reflectionMat, Vector4 plane)
{
reflectionMat.m00 = (1F - 2F*plane[0]*plane[0]);
reflectionMat.m01 = ( - 2F*plane[0]*plane[1]);
reflectionMat.m02 = ( - 2F*plane[0]*plane[2]);
reflectionMat.m03 = ( - 2F*plane[3]*plane[0]);
reflectionMat.m10 = ( - 2F*plane[1]*plane[0]);
reflectionMat.m11 = (1F - 2F*plane[1]*plane[1]);
reflectionMat.m12 = ( - 2F*plane[1]*plane[2]);
reflectionMat.m13 = ( - 2F*plane[3]*plane[1]);
reflectionMat.m20 = ( - 2F*plane[2]*plane[0]);
reflectionMat.m21 = ( - 2F*plane[2]*plane[1]);
reflectionMat.m22 = (1F - 2F*plane[2]*plane[2]);
reflectionMat.m23 = ( - 2F*plane[3]*plane[2]);
reflectionMat.m30 = 0F;
reflectionMat.m31 = 0F;
reflectionMat.m32 = 0F;
reflectionMat.m33 = 1F;
}
}
然后新建shader脚本
Shader "Mirrors/Bumped Specular" {
Properties {
_Color ("Main Color", Color) = (1,1,1,1)
_MainTex ("Base (RGB) Gloss (A)", 2D) = "white" {}
_BlendLevel("Main Material Blend Level",Range(0,1))=1
_SpecColor ("Specular Color", Color) = (0.5, 0.5, 0.5, 1)
_Shininess ("Shininess", Range (0.03, 1)) = 0.078125
_BumpMap ("Normalmap", 2D) = "bump" {}
_Bumpness ("Bump Rate",Range(0,1))= 0.5
_Ref ("For Mirror reflection,don't set it!", 2D) = "white" {}
_RefColor("Reflection Color",Color) = (1,1,1,1)
_RefRate ("Reflective Rate", Range (0, 1)) = 1
_Distortion ("Reflective Distortion", Range (0, 1)) = 0
}
SubShader {
Tags { "RenderType"="Opaque" }
LOD 400
CGPROGRAM
#pragma surface surf BlinnPhong
#pragma target 3.0
#pragma debug
sampler2D _MainTex;
sampler2D _BumpMap;
fixed4 _Color;
half _Shininess;
half _RefRate;
half _Bumpness;
half _BlendLevel;
half _Distortion;
fixed4 _RefColor;
sampler2D _Ref;
struct Input {
float2 uv_MainTex;
float2 uv_BumpMap;
float2 uv_Ref ;
float4 screenPos;
};
void surf (Input IN, inout SurfaceOutput o) {
fixed3 nor = UnpackNormal (tex2D(_BumpMap, IN.uv_BumpMap));
fixed4 tex = tex2D(_MainTex, IN.uv_MainTex);
float2 screenUV = IN.screenPos.xy / IN.screenPos.w;
screenUV += nor.xy * _Distortion;
fixed4 ref = tex2D(_Ref, screenUV);
o.Albedo = tex.rgb * _Color.rgb * _BlendLevel;
o.Emission = ref.rgb * _RefColor.rgb * _RefRate;
o.Normal = nor.rgb * _Bumpness;
o.Gloss = tex.a;
o.Alpha = tex.a * _Color.a;
o.Specular = _Shininess;
}
ENDCG
}
FallBack "Specular"
}
文中所用到的法线贴图
Grass.png