在Unity中我们需要配合使用材质 （Material） 和Unity Shader才能达到需要的效果。一个最常见的流程是
Unity中的材质需要结合一个GameObject的Mesh或者Particle Systems组件来工作。它决定了我们的游戏对象看起来是什么样子的（这当然也需要Unity Shader的配合）。
……在Unity中我们需要配合使用材质 （Material） 和Unity Shader才能达到需要的效果。一个最常见的流程是
Unity中的材质需要结合一个GameObject的Mesh或者Particle Systems组件来工作。它决定了我们的游戏对象看起来是什么样子的（这当然也需要Unity Shader的配合）。
……Render-Time Rendering, Third Edition》一书中将一个渲染流程分成3个阶段：应用阶段（Application Stage） 、几何阶段（Geometry Stage） 、光栅化阶段（Rasterizer Stage） 。
开发者有3个主要任务：
……Render-Time Rendering, Third Edition》一书中将一个渲染流程分成3个阶段：应用阶段（Application Stage） 、几何阶段（Geometry Stage） 、光栅化阶段（Rasterizer Stage） 。
开发者有3个主要任务：
……在Unity中创建一个项目，导入石头模型，下面就开始利用shader给石头做一个雪景覆盖.
未覆盖雪景的样子
覆盖了雪景的样子
我在代码中标注了1，2，3，4，5
// Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'
Shader "Custom/Diffuse Texture"
{
Properties
{
_Color ("Color", Color) = (1,1,1,1)
_MainTex ("Albedo (RGB)", 2D) = "white" {}
_Glossiness ("Smoothness", Range(0,1)) = 0.5
_Metallic ("Metallic", Range(0,1)) = 0.0
//1
_Bump("Bump", 2D) = "bump" {}
_Snow ("Snow Level", Range(0, 1)) = 0.1
_SnowColor ("Snow Color", Color) = (1.0, 1.0, 1.0, 1.0)
_SnowDirection ("Snow Direction", Vector) = (0, 1, 0)
_SnowDepth ("Snow Depth", Range(0, 0.3)) = 0.1
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 200
CGPROGRAM
// Physically based Standard lighting model, and enable shadows on all light types
#pragma surface surf CustomDiffuse vertex:vert
// Use shader model 3.0 target, to get nicer looking lighting
#pragma target 3.0
sampler2D _MainTex;
//2
sampler2D _Bump;
float _Snow;
float4 _SnowColor;
float4 _SnowDirection;
float _SnowDepth;
struct Input
{
float2 uv_MainTex;
//3
float2 uv_Bump;
float3 worldNormal; INTERNAL_DATA
};
half _Glossiness;
half _Metallic;
fixed4 _Color;
// Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
// See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
// #pragma instancing_options assumeuniformscaling
UNITY_INSTANCING_BUFFER_START(Props)
// put more per-instance properties here
UNITY_INSTANCING_BUFFER_END(Props)
void surf (Input IN, inout SurfaceOutput o)
{
// Albedo comes from a texture tinted by color
fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
//4
o.Normal = UnpackNormal(tex2D(_Bump, IN.uv_Bump));
if (dot(WorldNormalVector(IN, o.Normal), _SnowDirection.xyz) > lerp(1, -1, _Snow))
{
o.Albedo = _SnowColor.rgb;
}
else
{
o.Albedo = c.rgb;
}
o.Alpha = c.a;
}
inline float4 LightingCustomDiffuse (SurfaceOutput s, fixed3 lightDir, fixed atten)
{
float difLight = dot(s.Normal, lightDir);
float hLambert = difLight * 0.5 + 0.5;
float4 col;
col.rgb = s.Albedo * _LightColor0.rgb * (difLight * atten * 2);
col.a = s.Alpha;
return col;
}
//5
void vert(inout appdata_full v)
{
float4 sn = mul(transpose(unity_ObjectToWorld), _SnowDirection);
if (dot(v.normal, sn.xyz) >= lerp(1, -1, (_Snow * 2)/ 3))
{
v.vertex.xyz += (sn.xyz + v.normal) * _SnowDepth * _Snow;
}
}
ENDCG
}
FallBack "Diffuse"
}
声明并加入一个显示名称为Bump的贴图，用于放置法线图
……在Unity中创建一个项目，导入石头模型，下面就开始利用shader给石头做一个雪景覆盖.
未覆盖雪景的样子
覆盖了雪景的样子
我在代码中标注了1，2，3，4，5
// Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'
Shader "Custom/Diffuse Texture"
{
Properties
{
_Color ("Color", Color) = (1,1,1,1)
_MainTex ("Albedo (RGB)", 2D) = "white" {}
_Glossiness ("Smoothness", Range(0,1)) = 0.5
_Metallic ("Metallic", Range(0,1)) = 0.0
//1
_Bump("Bump", 2D) = "bump" {}
_Snow ("Snow Level", Range(0, 1)) = 0.1
_SnowColor ("Snow Color", Color) = (1.0, 1.0, 1.0, 1.0)
_SnowDirection ("Snow Direction", Vector) = (0, 1, 0)
_SnowDepth ("Snow Depth", Range(0, 0.3)) = 0.1
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 200
CGPROGRAM
// Physically based Standard lighting model, and enable shadows on all light types
#pragma surface surf CustomDiffuse vertex:vert
// Use shader model 3.0 target, to get nicer looking lighting
#pragma target 3.0
sampler2D _MainTex;
//2
sampler2D _Bump;
float _Snow;
float4 _SnowColor;
float4 _SnowDirection;
float _SnowDepth;
struct Input
{
float2 uv_MainTex;
//3
float2 uv_Bump;
float3 worldNormal; INTERNAL_DATA
};
half _Glossiness;
half _Metallic;
fixed4 _Color;
// Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
// See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
// #pragma instancing_options assumeuniformscaling
UNITY_INSTANCING_BUFFER_START(Props)
// put more per-instance properties here
UNITY_INSTANCING_BUFFER_END(Props)
void surf (Input IN, inout SurfaceOutput o)
{
// Albedo comes from a texture tinted by color
fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
//4
o.Normal = UnpackNormal(tex2D(_Bump, IN.uv_Bump));
if (dot(WorldNormalVector(IN, o.Normal), _SnowDirection.xyz) > lerp(1, -1, _Snow))
{
o.Albedo = _SnowColor.rgb;
}
else
{
o.Albedo = c.rgb;
}
o.Alpha = c.a;
}
inline float4 LightingCustomDiffuse (SurfaceOutput s, fixed3 lightDir, fixed atten)
{
float difLight = dot(s.Normal, lightDir);
float hLambert = difLight * 0.5 + 0.5;
float4 col;
col.rgb = s.Albedo * _LightColor0.rgb * (difLight * atten * 2);
col.a = s.Alpha;
return col;
}
//5
void vert(inout appdata_full v)
{
float4 sn = mul(transpose(unity_ObjectToWorld), _SnowDirection);
if (dot(v.normal, sn.xyz) >= lerp(1, -1, (_Snow * 2)/ 3))
{
v.vertex.xyz += (sn.xyz + v.normal) * _SnowDepth * _Snow;
}
}
ENDCG
}
FallBack "Diffuse"
}
声明并加入一个显示名称为Bump的贴图，用于放置法线图
……