source: GTP/branches/IllumWPdeliver2008dec/IlluminationWP/demos/OgreGames/CarGame/Media/materials/programs/GameTools_CausticSoftShadow.hlsl @ 3255

float4x4 world_IT;

float3x3 TransfModelToTangent( in  half3 Tangent, in half3 Binormal, in half3 Normal ) {
        half T2 = dot(Tangent, Tangent);
        half B2 = dot(Binormal, Binormal);
        half N2 = dot(Normal, Normal);
        half BT = dot(Binormal, Tangent);
        half det = B2 * T2 - BT * BT;

        return float3x3( (B2 * Tangent - BT * Binormal)/det, 
                         (T2 * Binormal - BT * Tangent)/det, 
                         Normal/N2 );
/*                                                      
        // simplified solution
        return float3x3(Tangent/T2, Binormal/B2, Normal/N2); 
*/
} 

struct VertOut
{
        half4 hPosition :POSITION;      
        half2 texCoord          :TEXCOORD;      
        half3 wPosition :TEXCOORD1;     
        half3 Normal            :TEXCOORD2;
        half3 Tangent   : TEXCOORD3;     // model space tangent vector
    half3 Binormal  : TEXCOORD4;         // model space binormal vector
};


VertOut deaultVS(half4 position : POSITION,
                half3 normal:NORMAL,
                half3 Tangent   : TEXCOORD1,     
                half2 texCoord : TEXCOORD0,             
                uniform float4x4 worldViewProj,
                uniform float4x4 world)
{
  VertOut OUT;
  OUT.texCoord = texCoord;
  OUT.hPosition = mul(worldViewProj, position);  
  OUT.wPosition = mul(world, position).xyz;
  OUT.Normal = normal;
  OUT.Tangent = Tangent;  
  OUT.Binormal = cross(Tangent, normal); 
  return OUT;    
}

half4 deaultPS(VertOut IN,
                                uniform sampler2D Texture : register(s0),
                                uniform sampler2D NormalMap : register(s1),
                                uniform half3 lightPosition,
                                uniform half3 cameraPos
                                ):COLOR
{
        half4 Color = half4(1,1,1,1);   
///get normal
        float3x3 ModelToTangent = float3x3(IN.Tangent, IN.Binormal, IN.Normal); 
        //float3x3 ModelToTangent = TransfModelToTangent(IN.Tangent, IN.Binormal, IN.Normal );
    half3 tNormal = tex2D(NormalMap, IN.texCoord).rgb;          
   
   
    half3 wNormal =mul(tNormal, ModelToTangent );
    //wNormal = IN.Normal;
    wNormal = normalize(mul( wNormal, world_IT ));
///shading
        half3 V = normalize(IN.wPosition - cameraPos);
        half3 light = (lightPosition - IN.wPosition) / 200.0;
        half3 L = normalize(light);
        half3 H = normalize(L+V);
        half4 lighting = lit(dot(wNormal, L),dot(wNormal, H), 80);
        
        half4 ambient = float4(0.1, 0.1, 0.1, 1.0);
        
        Color = tex2D(Texture, IN.texCoord) * (lighting.y  /*+ ambient*/) + lighting.z * half4(0.3,0.3,0.3,1); 
        
        return Color;
}