source: data/data_extern/programs/Cg/instancing.cg

void instancing_vp(uniform float3x4   worldMatrix3x4Array[80], float4 position : POSITION,
                                                float3 normal : NORMAL,
                                                float2 uv : TEXCOORD0,
                                                float index : TEXCOORD1,
                                                uniform float4x4 viewProjectionMatrix,
                                                uniform float4 lightPos,
                                                uniform float4 ambient,
                                                uniform float4 lightDiffuseColour,
                                                out float4 oPosition : POSITION,
                                                out float2 oUv : TEXCOORD0,
                                                out float4 Color : COLOR )
{
        // transform by indexed matrix
        float4 transformedPos = float4(mul(worldMatrix3x4Array[index], position).xyz, 1.0);
        
        // view / projection
        oPosition = mul(viewProjectionMatrix, transformedPos);
        oUv = uv;

        float3 norm = mul((float3x3)worldMatrix3x4Array[index], normal);
        
        float3 lightDir =       normalize(
                lightPos.xyz -  (transformedPos.xyz * lightPos.w));

        Color = ambient + saturate(dot(lightDir, norm)) * lightDiffuseColour;
        
        
}

/*
  Instancing shadow-caster pass
*/
void instancingCaster_vp(
        float4 position : POSITION,
        float3 normal   : NORMAL,
        float index     : TEXCOORD1,

        out float4 oPosition : POSITION,
        out float4 colour    : COLOR,
        // Support up to 80 bones of float3x4
        uniform float3x4   worldMatrix3x4Array[80],
        uniform float4x4 viewProjectionMatrix,
        uniform float4   ambient)
{
        // transform by indexed matrix
        float4 transformedPos = float4(mul(worldMatrix3x4Array[index], position).xyz, 1.0);

        // view / projection
        oPosition = mul(viewProjectionMatrix, transformedPos);
        
        colour = ambient;
        
}