Содержание

DirectX SDK SDKMESH

Remarks

DirectXTK

The VertexTypes.h header defines these commonly used vertex data structures:

Structure	Stride
VertexPosition	12 bytes
VertexPositionColor	28 bytes
VertexPositionTexture	20 bytes
VertexPositionDualTexture	28 bytes
VertexPositionNormal	24 bytes
VertexPositionColorTexture	36 bytes
VertexPositionNormalColor	40 bytes
VertexPositionNormalTexture	32 bytes
VertexPositionNormalColorTexture	48 bytes

Header

#include <VertexTypes.h>

Input Layout

Each type provides a D3D12_INPUT_LAYOUT_DESC structure which can be used when creating a Pipeline State Object (PSO):

D3D12_GRAPHICS_PIPELINE_STATE_DESC psoDesc = {};
psoDesc.InputLayout = VertexPositionColor::InputLayout;
...
DX::ThrowIfFailed(
    device->CreateGraphicsPipelineState(&psoDesc,
        IID_PPV_ARGS(m_pipelineState.ReleaseAndGetAddressOf())));

They are typically used with EffectPipelineStateDescription:

RenderTargetState rtState(m_deviceResources->GetBackBufferFormat(),
    m_deviceResources->GetDepthBufferFormat());

EffectPipelineStateDescription pd(
    &VertexPositionColor::InputLayout,
    CommonStates::Opaque,
    CommonStates::DepthDefault,
    CommonStates::CullNone,
    rtState);

Usage

Position (which uses the semantic "SV_Position") is required for all rendering. This is XMFLOAT3 (DXGI_FORMAT_R32G32B32_FLOAT).

Normal is required for any effect that supports lighting computations. This is XMFLOAT3 (DXGI_FORMAT_R32G32B32_FLOAT).

Color is for per-vertex coloring used by some effects. Color is typically XMFLOAT4(DXGI_FORMAT_R32G32B32A32_FLOAT).

Texture coordinates (which uses the semantic "TEXCOORD0") are XMFLOAT2 (DXGI_FORMAT_R32G32_FLOAT).

DualTexture coordinates (which uses the semantic "TEXCOORD0" and "TEXCOORD1") are XMFLOAT2 (DXGI_FORMAT_R32G32_FLOAT).

Geometry formats

See DirectXMesh for more information.

DirectX SDK SDKMESH

The .SDKMESH format describes input layouts as Direct3D 9 style vertex decls. There is therefore no specific vertex structure for .SDKMESH data and such input layouts are built on-the-fly. The Model loader attempts to create input layouts that match the needs of the standard Effects, so it can end up ignoring some of the vertex layout content if the critical content is found first.

Remarks

The DirectX 11 version of DirectX Tool Kit also defines VertexPositionNormalTangentColorTexture and VertexPositionNormalTangentColorTextureSkinning created to support the Visual Studio Directed Graph Shader Language (DGSL) effects pipeline which are not implemented for DirectX 12.
DirectX Tool Kit built-in Effects that require a tangent-space compute the tangent/bi-tangent in the shader from the normal and texture coordinates to simplify usage.

Christian Schüler, "Normal Mapping without Precomputed Tangents", ShaderX 5, Chapter 2.6, pp. 131 – 140 and this blog post