在DirectX 11中为着色器添加常规信息 - 在着色器中看不到法线？

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.

Answer 2

I don't know if it's your problem but something looks wrong here :-

{ "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 }, }; 

The entry for colour r32g32b32a32 type which is 16 bytes in size but that doesn't seem to be right, I'd expect the 24 to be 28 on the last line. Plus you set the input slot to 12, I'm not quite sure why?