Question

I wanted to add a normal map information for my shader. I was using tutorial 5 from DirectX 11 C++ SDK as a base.

The code for shader creating is (I’m putting it just to be sure I have posted every important information, but I think that only the D3D11_INPUT_ELEMENT_DESC layout[] matters):

// Compile the vertex shader
ID3DBlob* pVSBlob = NULL;
HRESULT hr = CompileShaderFromFile( strToWchart(vertexShaderFileName), "VS", "vs_4_0", &pVSBlob );

// Create the vertex shader
hr = device->CreateVertexShader( pVSBlob->GetBufferPointer(), pVSBlob->GetBufferSize(), NULL, &vertexShader );
if( FAILED( hr ) )
{   
pVSBlob->Release();
}


// Define the input layout
D3D11_INPUT_ELEMENT_DESC layout[] =
{
    { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
    { "COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0 },
    { "NORMAL", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 12, 24, D3D11_INPUT_PER_VERTEX_DATA, 0 },
};

UINT numElements = ARRAYSIZE( layout );

// Create the input layout
hr = device->CreateInputLayout( layout, numElements, pVSBlob->GetBufferPointer(),
                                      pVSBlob->GetBufferSize(), &*vertexLayout );
pVSBlob->Release();

    // Set the input layout
context->IASetInputLayout( *vertexLayout );

// Compile the pixel shader
ID3DBlob* pPSBlob = NULL;
hr = CompileShaderFromFile( strToWchart(pixelShaderFileName), "PS", "ps_4_0", &pPSBlob );

// Create the pixel shader
hr = device->CreatePixelShader( pPSBlob->GetBufferPointer(), pPSBlob->GetBufferSize(), NULL, &pixelShader );
pPSBlob->Release();

}

So simply I have changed D3D11_INPUT_ELEMENT_DESC layout[] to (adding “NORMAL” row):

D3D11_INPUT_ELEMENT_DESC layout[] =
{
    { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
    { "COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0 },
    { "NORMAL", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 12, 24, D3D11_INPUT_PER_VERTEX_DATA, 0 },
};

Than I have changed few lines in the box creating method:

// Create vertex buffer
SimpleVertex vertices[] =
{
    { XMFLOAT3(  - halfSize.getX(),  + halfSize.getY(),  - halfSize.getZ() ), XMFLOAT4( 0.0f, 0.0f, 1.0f, 1.0f ), XMFLOAT4( 0.0f, 0.0f, 1.0f, 1.0f ) },
    { XMFLOAT3(  + halfSize.getX(),  + halfSize.getY(),  - halfSize.getZ() ), XMFLOAT4( 0.0f, 1.0f, 0.0f, 1.0f ), XMFLOAT4( 0.0f, 1.0f, 1.0f, 1.0f ) },
    { XMFLOAT3(  + halfSize.getX(),  + halfSize.getY(),  + halfSize.getZ() ), XMFLOAT4( 0.0f, 1.0f, 1.0f, 1.0f ), XMFLOAT4( 0.0f, 0.0f, 1.0f, 1.0f ) },
    { XMFLOAT3(  - halfSize.getX(),  + halfSize.getY(),  + halfSize.getZ() ), XMFLOAT4( 1.0f, 0.0f, 0.0f, 1.0f ), XMFLOAT4( 0.0f, 0.0f, 1.0f, 1.0f ) },
    { XMFLOAT3(  - halfSize.getX(),  - halfSize.getY(),  - halfSize.getZ() ), XMFLOAT4( 1.0f, 0.0f, 1.0f, 1.0f ), XMFLOAT4( 0.0f, 1.0f, 1.0f, 1.0f ) },
    { XMFLOAT3(  + halfSize.getX(),  - halfSize.getY(),  - halfSize.getZ() ), XMFLOAT4( 1.0f, 1.0f, 0.0f, 1.0f ), XMFLOAT4( 0.0f, 0.0f, 1.0f, 1.0f ) },
    { XMFLOAT3(  + halfSize.getX(),  - halfSize.getY(),  + halfSize.getZ() ), XMFLOAT4( 1.0f, 1.0f, 1.0f, 1.0f ), XMFLOAT4( 1.0f, 0.0f, 1.0f, 0.0f ) },
    { XMFLOAT3(  - halfSize.getX(),  - halfSize.getY(),  + halfSize.getZ() ), XMFLOAT4( 0.0f, 0.0f, 0.0f, 1.0f ), XMFLOAT4( 0.0f, 0.0f, 1.0f, 1.0f ) },
};

So the last XMFLOAT4 in all rows are normal (not important that these are wrong normals, now I just want to make it visible in vertex shader).

I have also changed SimpleVertex:

struct SimpleVertex
{
    XMFLOAT3 Pos;
    XMFLOAT4 Color;
    XMFLOAT4 Normal;
};

And my shader to check if the normals exists:

cbuffer ConstantBuffer : register( b0 )
{
matrix World;
matrix View;
matrix Projection;
}

struct VS_INPUT
{
    float4 Pos : POSITION;
    float4 Color : COLOR;
float4 Normal : NORMAL; 
};

struct PS_INPUT
{
    float4 Pos : SV_POSITION;
    float4 Color : COLOR;
};

PS_INPUT VS( VS_INPUT input )
{
    PS_INPUT output = (PS_INPUT)0;



    output.Pos = mul( input.Pos, World );
    output.Pos = mul( output.Pos, View );
    output.Pos = mul( output.Pos, Projection );
output.Color = input.Normal; //just to know if I have a normals
    return output;
}

float4 PS( PS_INPUT input) : SV_Target
{
    return input.Color;
}

But the effect was just a black box (even with output.Color = input.Normal).

So, what’s the problem? I have to change something else to get normals info in the shader?

Answer 1

It looks like your D3D11_INPUT_ELEMENT_DESC array doesn’t match your vertex data. Try this:

// Define the input layout
D3D11_INPUT_ELEMENT_DESC layout[] =
{
  { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
  { "COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0 },
  { "NORMAL", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 28, D3D11_INPUT_PER_VERTEX_DATA, 0 }
};

The offset for your normals should include the offset for “POSITION” (12 byte) and “COLOR” (16 byte, not 12). And I have no idea why you set the input slot for this.