[RenderMonkey] Normal Mapping

[RenderMonkey] Normal Mapping

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// Vertex Shader

struct VS_INPUT
{
    float4 mPosition : POSITION;
    float3 mNormal : NORMAL;
    float3 mTangent : TANGENT;
    float3 mBinormal : BINORMAL;
    float2 mUV: TEXCOORD0;
};

struct VS_OUTPUT
{
    float4 mPosition : POSITION;
    float2 mUV : TEXCOORD0;
    float3 mLightDir : TEXCOORD1;
    float3 mViewDir : TEXCOORD2;
    float3 T : TEXCOORD3;
    float3 B : TEXCOORD4;
    float3 N : TEXCOORD5;
};

float4x4 gWorldMatrix;
float4x4 gWorldViewProjectionMatrix;

float4 gWorldLightPosition;
float4 gWorldCameraPosition;

VS_OUTPUT vs_main(VS_INPUT Input)
{
    VS_OUTPUT Output;

    Output.mPosition = mul(Input.mPosition, gWorldViewProjectionMatrix);
    Output.mUV = Input.mUV;

    float4 worldPosition = mul(Input.mPosition, gWorldMatrix);
    float3 lightDir = worldPosition.xyz - gWorldCameraPosition.xyz;
    Output.mLightDir = normalize(lightDir);

    float3 viewDir = normalize(worldPosition.xyz - gWorldCameraPosition.xyz);
    Output.mViewDir = viewDir;

    float3 worldNormal = mul(Input.mNormal, (float3x3)gWorldMatrix);
    Output.N = normalize(worldNormal);

    float3 worldTangent = mul(Input.mTangent, (float3x3)gWorldMatrix);
    Output.T = normalize(worldTangent);

    float3 worldBinormal = mul(Input.mBinormal, (float3x3)gWorldMatrix);
    Output.B = normalize(worldBinormal);

    return Output;
}

// Pixel Shader

struct PS_INPUT
{
    float2 mUV : TEXCOORD0;
    float3 mLightDir : TEXCOORD1;
    float3 mViewDir : TEXCOORD2;
    float3 T : TEXCOORD3;
    float3 B : TEXCOORD4;
    float3 N : TEXCOORD5;
};

sampler2D DiffuseSampler;
sampler2D SpecularSampler;
sampler2D NormalSampler;

float3 gLightColor;

float4 ps_main(PS_INPUT Input) : COLOR
{
   float3 tangentNormal = tex2D(NormalSampler, Input.mUV).xyz;
   tangentNormal = normalize(tangentNormal * 2 - 1);

   float3x3 TBN = float3x3(normalize(Input.T), normalize(Input.B), normalize(Input.N));
   TBN = transpose(TBN);
   float3 worldNormal = mul(TBN, tangentNormal);

   float4 albedo = tex2D(DiffuseSampler, Input.mUV);
   float3 lightDir = normalize(Input.mLightDir);
   float3 diffuse = saturate(dot(worldNormal, -lightDir));
   diffuse = gLightColor * albedo.rgb * diffuse;

   float3 specular = 0;
   if (diffuse.x > 0)
   {
      float3 reflection = reflect(lightDir, worldNormal);
      float3 viewDir = normalize(Input.mViewDir);

      specular = saturate(dot(reflection, -viewDir));
      specular = pow(specular, 20.0f);

      float4 specularIntensity = tex2D(SpecularSampler, Input.mUV);
      specular *= specularIntensity.rgb * gLightColor;
   }

   float3 ambient = float3(0.1f, 0.1f, 0.1f) * albedo;

   return float4(ambient + diffuse + specular, 1);
}