交互涟漪（水波）
时间：2022-12-31 14:00:00
原地址：【Unity可实时交互的涟漪效果_哔哩哔哩 (゜-゜)つロ 干杯~-bilibili
简单实现思路
点击物体的UV,传入shader，获得一张，根据点生生成的小圆球
传播图片shader，神奇的公式
float3 offset = float3(_SourceTex_TexelSize.xy,0); float col12 = tex2D(_SourceTex,i.uv offset.zy ).x; float col10 = tex2D(_SourceTex,i.uv - offset.zy ).x; float col01 = tex2D(_SourceTex,i.uv - offset.xz ).x; float col21 = tex2D(_SourceTex,i.uv offset.xz ).x; float col11 = tex2D(_PrevTex,i.uv).x; float finel = (col10 col12 col01 col21)*0.5 - col11; finel = finel*0.99; return float4(finel,0,0,1);将生成的高度场地地图传输到
法线贴图按高度生成
C#代码
using System.Collections; using System.Collections.Generic; using UnityEngine; public class MeshUVRipple : MonoBehaviour { public Camera camera; public float radius; private Shader _generateRippleHight; private RenderTexture _tempTexture; private RenderTexture _currentTexture; private RenderTexture _prevTexture; private Material _hightRipple; private Material _point_material; private Material material; private void Awake() { if (null == camera) { camera = Camera.main; } _currentTexture = CreatRT(); _tempTexture = CreatRT(); _prevTexture = CreatRT(); _point_material = new Material(Shader.Find("Custom/GenerateRippleHight")); _hightRipple = new Material(Shader.Find("Custom/HightRipple")); material = GetComponent().material; } private RenderTexture CreatRT() { var rt = new RenderTexture(1024, 1024, 0, RenderTextureFormat.RFloat); rt.Create(); return rt; } private Vector2 lastTexCoord; private void Update() { if (Input.GetMouseButton(0)) { RaycastHit hit; if (Physics.Raycast(camera.ScreenPointToRay(Input.mousePosition), out hit)) { if (Vector2.Distance(hit.textureCoord, lastTexCoord) >0.01f) { lastTexCoord = hit.textureCoord; DrawPoint(hit); } } } DrawRipple(); material.SetTexture("_RippleHightTex", _currentTexture); } private void DrawPoint(RaycastHit hit) { _point_material.SetFloat("_Radius", radius); _point_material.SetVector("_HitPos", hit.textureCoord); _point_material.SetTexture("_SourceTex", _currentTexture); Graphics.Blit(null, _tempTexture, _point_material); RenderTexture rt = _currentTexture; _currentTexture = _tempTexture; _tempTexture = rt; } private void DrawRipple() { _hightRipple.SetTexture("_SourceTex", _currentTexture); _hightRipple.SetTexture("_PrevTex", _prevTexture); Graphics.Blit(null, _tempTexture, _hightRipple); Graphics.Blit(_tempTexture, _prevTexture); RenderTexture rt = _prevTexture; _prevTexture = _currentTexture; _currentTexture = rt; } } 初始涟漪生成shader
Shader "Custom/GenerateRippleHight" { Properties { _MainTex ("Texture", 2D) = "white" {} } SubShader { Tags { "RenderType"="Opaque" } LOD 100 Pass { CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float2 uv : TEXCOORD0; float4 pos : SV_POSITION; }; sampler2D _SourceTex; float4 _SourceTex_ST; float2 _HitPos; floa _Radius;
v2f vert (appdata v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _SourceTex);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed4 col = tex2D(_SourceTex, i.uv);
float factor =max(0,_Radius-length(i.uv-_HitPos)/_Radius);
col.r += min( factor,1);
return col;
}
ENDCG
}
}
}
涟漪扩散shader
Shader "Custom/HightRipple"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 pos : SV_POSITION;
};
sampler2D _SourceTex;
sampler2D _PrevTex;
float4 _SourceTex_ST;
float4 _SourceTex_TexelSize;
v2f vert (appdata v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}
fixed4 frag (v2f i) : SV_Target
{
float3 offset = float3(_SourceTex_TexelSize.xy,0);
float col12 = tex2D(_SourceTex,i.uv + offset.zy ).x;
float col10 = tex2D(_SourceTex,i.uv - offset.zy ).x;
float col01 = tex2D(_SourceTex,i.uv - offset.xz ).x;
float col21 = tex2D(_SourceTex,i.uv + offset.xz ).x;
float col11 = tex2D(_PrevTex,i.uv).x;
float finel = (col10 + col12 + col01 + col21)*0.5 - col11;
finel = finel*0.99;
return float4(finel,0,0,1);
}
ENDCG
}
}
}
最终应用shader，简单的用了Blinn-Phong光照模型
Shader "Unlit/MeshRipple"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_Specular ("_Specular", Color) = (1,1,1,1)
_Diffuse ("_Diffuse", Color) = (1,1,1,1)
_heigth2normalFactor ("_heigth2normalFactor", Range(0.01,100)) = 0.1
}
SubShader
{
Tags { "RenderType" = "Opaque" "Queue" = "Transparent" }
LOD 100
Blend SrcAlpha OneMinusSrcAlpha
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 pos : SV_POSITION;
float4 worldPos : TEXCOORD1;
};
sampler2D _MainTex;
float4 _MainTex_ST;
sampler2D _RippleHightTex;
float4 _RippleHightTex_TexelSize;
float4 _Specular;
float4 _Diffuse;
float _heigth2normalFactor;
float3 HigthToNormal(sampler2D heigthTex ,float2 heigth_TexelSize , float2 uv)
{
float3 offset = float3(heigth_TexelSize.xy,0);
float factor = _heigth2normalFactor;
float3 S = float3(1,0, (tex2D(heigthTex,uv + offset.xz).x - tex2D(heigthTex,uv - offset.xz).x)*factor);
float3 T = float3(0,1, (tex2D(heigthTex,uv + offset.zy).x - tex2D(heigthTex,uv - offset.zy).x)*factor);
float3 d = cross(S,T)+float3(0.5,0.5,1);
return d;
}
v2f vert (appdata v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.worldPos = mul(unity_ObjectToWorld,v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
float4 frag (v2f i) : SV_Target
{
float4 col = tex2D(_MainTex, i.uv)*_Diffuse;
float3 normal = HigthToNormal(_RippleHightTex,_RippleHightTex_TexelSize.xy, i.uv);
normal = normalize(normal);
float3 worldLight = normalize(_WorldSpaceLightPos0.xyz);
float3 view = normalize(_WorldSpaceCameraPos.xyz - i.worldPos.xyz);
float3 halfDir = normalize(worldLight + view);
float3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0,dot(normal, halfDir)), 4);
col.rgb += specular;
return col;
}
ENDCG
}
}
}
