本文寫於2017-6-2,原創,轉載請註明。
以下爲正文
………………………………………………………………………………………………………………………………
半年前看的一篇講溶解特效的文章,然而只講思路,沒有源文件,最近挺流行這種特效的,決定嘗試一下。
最後結合網絡上一些不成熟的例子和文章的思路,寫了一個表面着色器Shader,效果挺不錯的,達到了要求,這裏記錄一下。
先上效果圖:
面板可輸入各類數值,注意給一個噪聲貼圖(這裏是用Photoshop分層雲彩濾鏡生成):
以下是Shader源碼:
Shader "Custom/MyDissolveSurface" {
Properties {
_Color ("顏色", Color) = (1,1,1,1)
_MainTex ("主貼圖 (RGB)", 2D) = "white" {}
_Glossiness ("平滑度", Range(0,1)) = 0.5
_Metallic ("金屬性", Range(0,1)) = 0.0
_NoiseTex ("噪聲貼圖 (R)",2D) = "white"{}
_EdgeWidth("邊緣寬度",Range(0,0.5)) = 0.1
_EdgeColor("邊緣顏色",Color) = (1,1,1,1)
_EdgeThresholdValue ("硬邊緣閾值(0爲不使用)",Range(0,1)) = 0.5
_DissolvePercentage ("溶解百分比",Range(0,1)) = 0
}
SubShader {
Tags { "RenderType"="Opaque" }
LOD 200
CGPROGRAM
// Physically based Standard lighting model, and enable shadows on all light types
//原編譯指令
//#pragma surface surf Standard fullforwardshadows
//增加addshadow以獲得正確的陰影
#pragma surface surf Standard fullforwardshadows addshadow
// Use shader model 3.0 target, to get nicer looking lighting
#pragma target 3.0
sampler2D _MainTex;
sampler2D _NoiseTex;
float _EdgeWidth;
float4 _EdgeColor;
float _EdgeThresholdValue;
float _DissolvePercentage;
struct Input {
float2 uv_MainTex;
float3 worldPos;
};
half _Glossiness;
half _Metallic;
fixed4 _Color;
void surf (Input IN, inout SurfaceOutputStandard o) {
// Albedo comes from a texture tinted by color
fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
// Metallic and smoothness come from slider variables
o.Metallic = _Metallic;
o.Smoothness = _Glossiness;
o.Alpha = c.a;
float DissolveFactor = saturate(_DissolvePercentage);
//使用固定座標
// float noiseValue = tex2D(_NoiseTex,IN.uv_MainTex).r;
//使用世界座標
float noiseValue = tex2D(_NoiseTex,IN.worldPos.rg).r;
//如果該值對應噪聲圖的值更大,則拋棄
if(noiseValue <= DissolveFactor)
{
discard;
}
float4 texColor = tex2D(_MainTex,IN.uv_MainTex);
float EdgeFactor = saturate((noiseValue - DissolveFactor)/(_EdgeWidth*DissolveFactor));
float4 BlendColor = texColor * _EdgeColor;
if(_EdgeThresholdValue>0){
//不使用漸變(硬邊緣)
float HardEdgeFactor=EdgeFactor;
if(HardEdgeFactor>_EdgeThresholdValue){
HardEdgeFactor=1;
o.Emission =0;
}else{
HardEdgeFactor=0;
o.Emission =_EdgeColor;
}
o.Albedo = lerp(texColor,BlendColor,1-EdgeFactor);
}else{
o.Emission =0;
//使用漸變(軟邊緣)
if(_EdgeThresholdValue>=1){
o.Albedo = BlendColor;
o.Alpha=0;
}else{
o.Albedo = lerp(texColor,BlendColor,1 - EdgeFactor);
}
}
}
ENDCG
}
FallBack "Diffuse"
}
參考文章:
《Trifox》中的遮擋處理和溶解着色器技術(上)
http://gad.qq.com/article/detail/7190982
《Trifox》中的遮擋處理和溶解着色器技術(下)
http://gad.qq.com/article/detail/7190975
Shader溶解特效
http://blog.csdn.net/xiaoge132/article/details/51657246