I don't think you are doing anything wrong - there's a fault in the shader. I assume you are using this one from EVOLVED:
//********************************************************************************************
//
// Bumpmapping with 8 lights ( 2 passes) (ps v1.4 , vs v1.1)
// by EVOLVED
//
//
/////////////////////////////////////////////
// un-TWEAKABLES
matrix WorldViewProj : WorldViewProjection;
matrix World : World;
matrix ViewInv : ViewInverse;
// TWEAKABLES
float3 LP_1 <> = {100.0f, 100.0f, -100.0f}; // light position 1
float LR_1 <> = 50.0; // light range 1
float4 LC_1 <> = {1.0f, 1.0f, 1.0f, 0.0f}; // light color 1
float3 LP_2 <> = {100.0f, 100.0f, -100.0f}; // light position 2
float LR_2 <> = 50.0; // light range 2
float4 LC_2 <> = {1.0f, 0.0f, 0.0f, 0.0f}; // light color 2
float3 LP_3 <> = {100.0f, 100.0f, -100.0f}; // etc..
float LR_3 <> = 50.0;
float4 LC_3 <> = {0.0f, 1.0f, 0.0f, 0.0f};
float3 LP_4 <> = {100.0f, 100.0f, -100.0f};
float LR_4 <> = 50.0;
float4 LC_4 <> = {0.0f, 0.0f, 1.0f, 0.0f};
float3 LP_5 <> = {100.0f, 100.0f, -100.0f};
float LR_5 <> = 50.0;
float4 LC_5 <> = {1.0f, 1.0f, 0.0f, 0.0f};
float3 LP_6 <> = {100.0f, 100.0f, -100.0f};
float LR_6 <> = 50.0;
float4 LC_6 <> = {1.0f, 0.0f, 1.0f, 0.0f};
float3 LP_7 <> = {100.0f, 100.0f, -100.0f};
float LR_7 <> = 50.0;
float4 LC_7 <> = {0.0f, 1.0f, 1.0f, 0.0f};
float3 LP_8 <> = {100.0f, 100.0f, -100.0f};
float LR_8 <> = 50.0;
float4 LC_8 <> = {1.0f, 0.50f, 0.0f, 0.0f};
//********************************************************************************************
// Textures
texture colorTexture < string Name = "<defalt>"; >; // grab our base texture (TextCord 0)
sampler2D colorSampler = sampler_state // grab our base sampler
{
Texture = <colorTexture>;
};
texture normalTexture <string Name = "<defalt>"; >; // grab our noramlmap texture (TextCord 1)
sampler2D normalSampler = sampler_state // grab our noramlmap sampler
{
Texture = <normalTexture>;
};
//********************************************************************************************
// DATA STRUCTS
// vertex data
struct appdata {
float4 Position : POSITION;
float4 UV : TEXCOORD;
float3 Normal : NORMAL;
float3 Tangent : TANGENT;
float3 Binormal : BINORMAL;
};
// vertex to pixel shader data
struct VSOutput {
float4 pos : POSITION;
float2 uv : TEXCOORD0;
float3 Light1 : TEXCOORD1;
float3 Light2 : TEXCOORD2;
float3 Light3 : TEXCOORD3;
float3 Light4 : TEXCOORD4;
};
//********************************************************************************************
VSOutput mainVS1(appdata IN) // 1st vertex data for light 1-4
{
VSOutput OUT;
OUT.pos = mul( IN.Position , WorldViewProj ); // out pos
OUT.uv = IN.UV; // out uv data
float3 WP = mul(IN.Position, World).xyz; // world space position
float3x3 TM = {IN.Tangent,IN.Binormal,IN.Normal}; // tangent Matrix
TM = transpose(TM);
float3 L = LP_1 - WP; // light vector in would space pos
float Ld = (1/length(L)); // light range
float3 LO = mul(L,TM); // multiply light vector x tangent Matrix
OUT.Light1 = normalize(LO) * (Ld*LR_1)-0.2 ; // normalize our final lv and add range
L = LP_2 - WP; // do the above 3 more times
Ld = (1/length(L));
LO = mul(L,TM);
OUT.Light2 = normalize(LO) * (Ld*LR_2)-0.2 ;
L = LP_3 - WP;
Ld = (1/length(L));
LO = mul(L,TM);
OUT.Light3 = normalize(LO) * (Ld*LR_3)-0.2 ;
L = LP_4 - WP;
Ld = (1/length(L));
LO = mul(L,TM);
OUT.Light4 = normalize(LO) * (Ld*LR_4)-0.2 ;
return OUT;
}
VSOutput mainVS2(appdata IN) // 2nd vertex data for light 5-8
{
VSOutput OUT;
OUT.pos = mul( IN.Position , WorldViewProj );
OUT.uv = IN.UV;
float4 TP = float4(IN.Position);
float3 WP = mul(TP, World).xyz;
float3x3 TM = {IN.Tangent,IN.Binormal,IN.Normal};
TM = transpose(TM);
float3 L = LP_5 - WP;
float Ld = (1/length(L));
float3 LO = mul(L,TM);
OUT.Light1 = normalize(LO) * (Ld*LR_5)-0.2 ;
L = LP_6 - WP;
Ld = (1/length(L));
LO = mul(L,TM);
OUT.Light2 = normalize(LO) * (Ld*LR_6)-0.2 ;
L = LP_7 - WP;
Ld = (1/length(L));
LO = mul(L,TM);
OUT.Light3 = normalize(LO) * (Ld*LR_7)-0.2 ;
L = LP_8 - WP;
Ld = (1/length(L));
LO = mul(L,TM);
OUT.Light4 = normalize(LO) * (Ld*LR_8)-0.2 ;
return OUT;
}
//********************************************************************************************
float4 PS_bumpmap_lights1(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv); // base map
float4 NB=tex2D(normalSampler,IN.uv)*2-1; // noraml map
float3 LV=IN.Light1; // get light vector position
float GLB=saturate(dot(NB,LV)); // combine the light vector with the noraml map
float4 TN=GLB*LC_1 ; // add color
float4 result= TB * TN; // return this
return result;
}
float4 PS_bumpmap_lights2(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv);
float4 NB=tex2D(normalSampler,IN.uv)*2-1;
float3 LV=IN.Light1; // get light vector position 1
float GLB=saturate(dot(NB,LV)); // combine
float4 TN=GLB*LC_1 ; // add color
LV=IN.Light2; // get light vector position 2
GLB=saturate(dot(NB,LV)); // combine
TN=TN+GLB*LC_2 ; // add new result to the previous + color
float4 result= TB * TN ; // return this
return result;
}
float4 PS_bumpmap_lights3(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv);
float4 NB=tex2D(normalSampler,IN.uv)*2-1;
float3 LV=IN.Light1;
float GLB=saturate(dot(NB,LV));
float4 TN=GLB*LC_1 ;
LV=IN.Light2;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_2 ;
LV=IN.Light3;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_3 ;
float4 result= TB * TN ;
return result;
}
float4 PS_bumpmap_lights4(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv);
float4 NB=tex2D(normalSampler,IN.uv)*2-1;
float3 LV=IN.Light1;
float GLB=saturate(dot(NB,LV));
float4 TN=GLB*LC_1 ;
LV=IN.Light2;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_2 ;
LV=IN.Light3;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_3 ;
LV=IN.Light4;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_4 ;
float4 result= TB * TN ;
return result;
}
float4 PS_bumpmap_lights5(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv);
float4 NB=tex2D(normalSampler,IN.uv)*2-1;
float3 LV=IN.Light1;
float GLB=saturate(dot(NB,LV));
float4 TN=GLB*LC_5 ;
float4 result= TB * TN ;
return result;
}
float4 PS_bumpmap_lights6(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv);
float4 NB=tex2D(normalSampler,IN.uv)*2-1;
float3 LV=IN.Light1;
float GLB=saturate(dot(NB,LV));
float4 TN=GLB*LC_5 ;
LV=IN.Light2;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_6 ;
float4 result= TB * TN ;
return result;
}
float4 PS_bumpmap_lights7(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv);
float4 NB=tex2D(normalSampler,IN.uv)*2-1;
float3 LV=IN.Light1;
float GLB=saturate(dot(NB,LV));
float4 TN=GLB*LC_5 ;
LV=IN.Light2;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_6 ;
LV=IN.Light3;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_7 ;
float4 result= TB * TN ;
return result;
}
float4 PS_bumpmap_lights8(VSOutput IN) : COLOR
{
float4 TB=tex2D(colorSampler,IN.uv);
float4 NB=tex2D(normalSampler,IN.uv)*2-1;
float3 LV=IN.Light1;
float GLB=saturate(dot(NB,LV));
float4 TN=GLB*LC_5 ;
LV=IN.Light2;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_6 ;
LV=IN.Light3;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_7 ;
LV=IN.Light4;
GLB=saturate(dot(NB,LV));
TN=TN+GLB*LC_8 ;
float4 result= TB * TN ;
return result;
}
//********************************************************************************************
// technique
technique lighting1
{
pass one
{
VertexShader = compile vs_1_1 mainVS1(); // run VS v1.1
PixelShader = compile ps_1_4 PS_bumpmap_lights1(); // run PS v1.4
}
}
technique lighting2
{
pass one
{
VertexShader = compile vs_1_1 mainVS1();
PixelShader = compile ps_1_4 PS_bumpmap_lights2();
}
}
technique lighting3
{
pass one
{
VertexShader = compile vs_1_1 mainVS1();
PixelShader = compile ps_1_4 PS_bumpmap_lights3();
}
}
technique lighting4
{
pass one
{
VertexShader = compile vs_1_1 mainVS1();
PixelShader = compile ps_1_4 PS_bumpmap_lights4();
}
}
technique lighting5
{
pass one
{
VertexShader = compile vs_1_1 mainVS1();
PixelShader = compile ps_1_4 PS_bumpmap_lights4();
}
pass two
{
AlphaBlendEnable = True;
SrcBlend = One;
DestBlend = One;
VertexShader = compile vs_1_1 mainVS2();
PixelShader = compile ps_1_4 PS_bumpmap_lights5();
}
}
technique lighting6
{
pass one
{
VertexShader = compile vs_1_1 mainVS1();
PixelShader = compile ps_1_4 PS_bumpmap_lights4();
}
pass two
{
AlphaBlendEnable = True;
SrcBlend = One;
DestBlend = One;
VertexShader = compile vs_1_1 mainVS2();
PixelShader = compile ps_1_4 PS_bumpmap_lights6();
}
}
technique lighting7
{
pass one
{
VertexShader = compile vs_1_1 mainVS1();
PixelShader = compile ps_1_4 PS_bumpmap_lights4();
}
pass two
{
AlphaBlendEnable = True;
SrcBlend = One;
DestBlend = One;
VertexShader = compile vs_1_1 mainVS2();
PixelShader = compile ps_1_4 PS_bumpmap_lights7();
}
}
technique lighting8
{
pass one
{
VertexShader = compile vs_1_1 mainVS1();
PixelShader = compile ps_1_4 PS_bumpmap_lights4();
}
pass two
{
AlphaBlendEnable = True;
SrcBlend = One;
DestBlend = One;
VertexShader = compile vs_1_1 mainVS2();
PixelShader = compile ps_1_4 PS_bumpmap_lights8();
}
}
//********************************************************************************************
I'm sure EVOLVED has fixed that issue in his more recent shaders which you can download from his site
http://www.evolved-software.com/shaders/advlighting.html (although it seems that some of the links on his site don't work properly any more
).
If you're still stuck I'll see if I can fix the code later today - the fix should be straightforward.
