   //  
   // lColor = light color, uv = texture coordinates for normal map and diffuse map, 
   // LV = light vector, the ambientColor constant is set with cgGLSetParameter3fv.
   //
   float4 main(
	   float2 uv        : TEXCOORD0,
	   float3 vLightVector : TEXCOORD1,
	   float3 position : POSITION,
	   uniform sampler2D normalMap : TEXUNIT0,
	   uniform float3 LightVec,
	   uniform float3 ambientColor) : COLOR
	{
	 float3 N = 2.0f * (tex2D(normalMap, uv).xyz - 0.5f);
	 vLightVector = normalize(vLightVector);
	 float diffuse = dot(vLightVector, N);
	 float3 diffuseMaterial = float3(0.0, 1.0, 0.0);
	 return float4(diffuse * diffuseMaterial, 1);
	 //return float4(N, 1);
	}
