公式相关，点光源版本的实现请看上一节
添加链接描述
趁着春节做一点点小工作，把定向光版本也补全了
效果
定向光版
点光源版
源码
点光源：fwadd
节点着色器阶段求解切线空间下的光源坐标，传入片元着色器阶段计算
定向光：fwbase
节点着色器阶段直接算切线空间下的光照方向
两个计算texcoord偏移的函数没有单独拿出来，请讲究着看看
Shader "Unlit/parrallax_Map"
{
Properties
{
_Color ("Color Tint", Color) = (1, 1, 1, 1)
_MainTex ("Texture", 2D) = "white" {
}
_NormalTex("Normal Map", 2D) = "white"{
}
_BumpScale ("bump scale", float) = 1.0
_DispTex("Disp Map", 2D) = "white"{
}
_Specular ("Specular", Color) = (1, 1, 1, 1)
_Gloss ("Gloss", Range(8.0, 256)) = 20
_height_scale("Height_scale", Range(0, 2)) = 1.0
}
SubShader
{
Tags {
"RenderType"="Opaque" }
LOD 100
Pass
{
Tags {
"LightMode"="ForwardBase" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_fwbase
#include "UnityCG.cginc"
#include "Lighting.cginc"
struct v2f
{
float4 pos : SV_POSITION;
half2 uv : TEXCOORD0;
float3 TanLightDir : TEXCOORD1;
float3 TanViewPos : TEXCOORD2;
float3 TanFragPos : TEXCOORD3;
//float3 T : TEXCOORD4;
//float3 B : TEXCOORD5;
//float3 N : TEXCOORD6;
};
sampler2D _MainTex;
float4 _MainTex_ST;
sampler2D _NormalTex;
sampler2D _DispTex;
float _BumpScale;
fixed4 _Color;
fixed4 _Specular;
float _Gloss;
float _height_scale;
v2f vert (appdata_tan v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
float3 FragPos = mul(UNITY_MATRIX_M, v.vertex).xyz;
fixed3 worldNormal = UnityObjectToWorldNormal(v.normal);
fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);
fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w;
float3x3 TBN = transpose(float3x3(worldTangent, worldBinormal, worldNormal));
o.TanLightDir = mul(TBN , UnityWorldSpaceLightDir(worldPos)) ;
o.TanViewPos = mul(TBN , _WorldSpaceCameraPos) ;
o.TanFragPos = mul(TBN , FragPos);
return o;
}
float2 steep_ParallaxMapping(float2 texCoords, fixed3 viewDir)
{
float minLayers = 10;
float maxLayers = 20;
float numLayers = lerp(maxLayers, minLayers, abs(dot(float3(0.0, 0.0, 1.0), viewDir)));
float LayerDepth = 1.0 / numLayers;
float currentLayerDepth = 0.0;
float2 P = viewDir.xy / viewDir.z * _height_scale;
float2 deltaTexCoords = P / numLayers;
float2 currentTexCoords = texCoords;
float currentDepthMapValue = tex2D(_DispTex, currentTexCoords).r;
while(currentLayerDepth < currentDepthMapValue)
{
currentTexCoords -= deltaTexCoords;
currentDepthMapValue = tex2Dlod(_DispTex, float4(currentTexCoords, 0.0, 0.0)).r;
currentLayerDepth += LayerDepth;
}
return currentTexCoords;
}
float2 ParallaxOcclusionMapping(float2 texCoords, fixed3 viewDir)
{
float minLayers = 10;
float maxLayers = 20;
float numLayers = lerp(maxLayers, minLayers, abs(dot(float3(0.0, 0.0, 1.0), viewDir)));
float LayerDepth = 1.0 / numLayers;
float currentLayerDepth = 0.0;
float2 P = viewDir.xy / viewDir.z * _height_scale;
float2 deltaTexCoords = P / numLayers;
float2 currentTexCoords = texCoords;
float currentDepthMapValue = tex2D(_DispTex, currentTexCoords).r;
while(currentLayerDepth < currentDepthMapValue)
{
currentTexCoords -= deltaTexCoords;
currentDepthMapValue = tex2Dlod(_DispTex, float4(currentTexCoords, 0.0, 0.0)).r;
currentLayerDepth += LayerDepth;
}
float2 prevTexCoords = currentTexCoords + deltaTexCoords;
float afterDepth = currentDepthMapValue - currentLayerDepth;
float beforeDepth = tex2D(_DispTex, prevTexCoords).r - currentLayerDepth + LayerDepth;
float weight = afterDepth / (afterDepth - beforeDepth);
float2 finalTexCoords = prevTexCoords * weight + currentTexCoords * (1.0 - weight);
return finalTexCoords;
}
fixed4 frag (v2f i) : SV_Target
{
// Compute the light and view dir in world space
fixed3 lightDir = normalize(i.TanLightDir);
fixed3 viewDir = normalize(i.TanViewPos - i.TanFragPos);
float2 texcoords = i.uv;
texcoords = ParallaxOcclusionMapping(i.uv, viewDir);
//texcoords = steep_ParallaxMapping(i.uv, viewDir);
if(texcoords.x > 1.0 || texcoords.y > 1.0 || texcoords.x < 0.0 || texcoords.y < 0.0)
discard;
fixed3 bump = tex2D(_NormalTex, texcoords).rgb;
bump = normalize(bump * 2.0 - 1.0);
fixed3 albedo = tex2D(_MainTex, texcoords).rgb * _Color.rgb;
fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(bump, lightDir));
fixed3 halfDir = normalize(lightDir + viewDir);
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0, dot(bump, halfDir)), _Gloss);
return fixed4(ambient + diffuse + specular, 1.0);
}
ENDCG
}
Pass
{
Tags {
"LightMode"="ForwardAdd" }
Blend One One
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_fwadd
#include "UnityCG.cginc"
#include "Lighting.cginc"
struct v2f
{
float4 pos : SV_POSITION;
half2 uv : TEXCOORD0;
float3 TanLightPos : TEXCOORD1;
float3 TanViewPos : TEXCOORD2;
float3 TanFragPos : TEXCOORD3;
//float3 T : TEXCOORD4;
//float3 B : TEXCOORD5;
//float3 N : TEXCOORD6;
};
sampler2D _MainTex;
float4 _MainTex_ST;
sampler2D _NormalTex;
sampler2D _DispTex;
float _BumpScale;
fixed4 _Color;
fixed4 _Specular;
float _Gloss;
float _height_scale;
v2f vert (appdata_tan v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
float3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
float3 FragPos = mul(UNITY_MATRIX_M, v.vertex).xyz;
fixed3 worldNormal = UnityObjectToWorldNormal(v.normal);
fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);
fixed3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w;
float3x3 TBN = transpose(float3x3(worldTangent, worldBinormal, worldNormal));
o.TanLightPos = mul(TBN , _WorldSpaceLightPos0) ;
o.TanViewPos = mul(TBN , _WorldSpaceCameraPos) ;
o.TanFragPos = mul(TBN , FragPos);
return o;
}
float2 steep_ParallaxMapping(float2 texCoords, fixed3 viewDir)
{
float minLayers = 10;
float maxLayers = 20;
float numLayers = lerp(maxLayers, minLayers, abs(dot(float3(0.0, 0.0, 1.0), viewDir)));
float LayerDepth = 1.0 / numLayers;
float currentLayerDepth = 0.0;
float2 P = viewDir.xy / viewDir.z * _height_scale;
float2 deltaTexCoords = P / numLayers;
float2 currentTexCoords = texCoords;
float currentDepthMapValue = tex2D(_DispTex, currentTexCoords).r;
while(currentLayerDepth < currentDepthMapValue)
{
currentTexCoords -= deltaTexCoords;
currentDepthMapValue = tex2Dlod(_DispTex, float4(currentTexCoords, 0.0, 0.0)).r;
currentLayerDepth += LayerDepth;
}
return currentTexCoords;
}
float2 ParallaxOcclusionMapping(float2 texCoords, fixed3 viewDir)
{
float minLayers = 10;
float maxLayers = 20;
float numLayers = lerp(maxLayers, minLayers, abs(dot(float3(0.0, 0.0, 1.0), viewDir)));
float LayerDepth = 1.0 / numLayers;
float currentLayerDepth = 0.0;
float2 P = viewDir.xy / viewDir.z * _height_scale;
float2 deltaTexCoords = P / numLayers;
float2 currentTexCoords = texCoords;
float currentDepthMapValue = tex2D(_DispTex, currentTexCoords).r;
while(currentLayerDepth < currentDepthMapValue)
{
currentTexCoords -= deltaTexCoords;
currentDepthMapValue = tex2Dlod(_DispTex, float4(currentTexCoords, 0.0, 0.0)).r;
currentLayerDepth += LayerDepth;
}
float2 prevTexCoords = currentTexCoords + deltaTexCoords;
float afterDepth = currentDepthMapValue - currentLayerDepth;
float beforeDepth = tex2D(_DispTex, prevTexCoords).r - currentLayerDepth + LayerDepth;
float weight = afterDepth / (afterDepth - beforeDepth);
float2 finalTexCoords = prevTexCoords * weight + currentTexCoords * (1.0 - weight);
return finalTexCoords;
}
fixed4 frag (v2f i) : SV_Target
{
// Compute the light and view dir in world space
fixed3 lightDir = normalize(i.TanLightPos - i.TanFragPos);
fixed3 viewDir = normalize(i.TanViewPos - i.TanFragPos);
float2 texcoords = i.uv;
texcoords = ParallaxOcclusionMapping(i.uv, viewDir);
//texcoords = steep_ParallaxMapping(i.uv, viewDir);
if(texcoords.x > 1.0 || texcoords.y > 1.0 || texcoords.x < 0.0 || texcoords.y < 0.0)
discard;
fixed3 bump = tex2D(_NormalTex, texcoords).rgb;
bump = normalize(bump * 2.0 - 1.0);
fixed3 albedo = tex2D(_MainTex, texcoords).rgb * _Color.rgb;
fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(bump, lightDir));
fixed3 halfDir = normalize(lightDir + viewDir);
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0, dot(bump, halfDir)), _Gloss);
return fixed4(ambient + diffuse + specular, 1.0);
}
ENDCG
}
}
FallBack "Specular"
}