HLSL Pixel Shader Sematics

Question

I have a HLSl pixel shader that I'm using to create a deferred buffer, I have simplified the code to show you:

struct PS_INPUT
{
    float4 PosWVP                   : SV_POSITION;
    float4 NormalWorld              : NORMAL2;
};

struct PS_OUTPUT
{
    float4 PosWorld                 : POSITION;
    float4 NormalWorld              : NORMAL2;
};

PS_OUTPUT main(PS_INPUT input) : SV_Target
{
    PS_OUTPUT output = (PS_OUTPUT)0;

    output.PosWorld = input.PosWorld;
    output.NormalWorld = input.NormalWorld;

    return output; 
}

When I compile this code, I get this warning warning X3576: semantics in type overridden by variable/function or enclosing type, what is this warning and how can I fix it?

Answer 1

I think the problem is that your pixel shader returns a structure, so each element of that structure need to have an SV_TARGET semantic and not the whole struct, so:

struct PS_OUTPUT
{
    float4 PosWorld                 : SV_TARGET0; //changed sematic
    float4 NormalWorld              : SV_TARGET1; //changed sematic
};

PS_OUTPUT main(PS_INPUT input) //there is no semantic here
{
    PS_OUTPUT output = (PS_OUTPUT)0;

    output.PosWorld = input.PosWorld;
    output.NormalWorld = input.NormalWorld;

    return output; 
}