This effect provides a way to visualize normals, tangents, and binormals/bitangents for debugging purposes. This effect also supports GPU instancing.

Related tutorials: Using advanced shaders, Multistream rendering and instancing

classDiagram
class Mode{
    <<enumeration>>
    Mode_Default
    Mode_Normals
    Mode_Tangents
    Mode_BiTangents
}
class IEffect{
    <<Interface>>
    +Apply()
    +GetVertexShaderBytecode()
}
class IEffectMatrices{
    <<Interface>>
    +SetWorld()
    +SetView()
    +SetProjection()
    +SetMatrices()
}
class DebugEffect{
    +SetMode()
    +SetHemisphericalAmbientColor()
    +SetAlpha()
    +SetVertexColorEnabled()
    +SetBiasedVertexNormals()
    +SetInstancingEnabled()
}
DebugEffect  .. Mode
DebugEffect --|> IEffect
DebugEffect --|> IEffectMatrices

class DirectX::DebugEffect :
    public DirectX::IEffect,
    public DirectX::IEffectMatrices

#include <Effects.h>

Construction requires a Direct3D 11 device.

std::unique_ptr<Debugffect> effect;

effect = std::make_unique<DebugEffect>(device);

For exception safety, it is recommended you make use of the C++ RAII pattern and use a std::unique_ptr or std::shared_ptr

PBREffect supports IEffect and IEffectMatrices.

This effect requires SV_Position, NORMAL, and TEXCOORD0. If per-vertex colors are enabled, it also requires COLOR.

If instancing is enabled, this effect also requires these vertex elements:

"InstMatrix",  0, DXGI_FORMAT_R32G32B32A32_FLOAT
"InstMatrix",  1, DXGI_FORMAT_R32G32B32A32_FLOAT
"InstMatrix",  2, DXGI_FORMAT_R32G32B32A32_FLOAT

• SetMode: Sets which debug shader to use. Defaults to Mode_Default:

• SetAlpha: Sets the alpha (transparency) of the effect. Defaults to 1 (fully opaque).

• SetHemisphericalAmbientColor: The default mode uses a simple hemispherical ambient lighting so you can see the object with some 3D clues regardless of overall scene lighting. It defaults to using White to Black. This property can set different upper/lower colors.

• SetVertexColorEnabled: Enables per-vertex color. Defaults to false. Modifying this setting requires recreating associated input layouts, and enabling it requires COLOR.

• SetBiasedVertexNormals: Enables support for compressed vertex normals which require *2 - 1 biasing at runtime such as DXGI_FORMAT_R10G10B10A2_UNORM.

• SetInstancingEnabled: Enables support for per-vertex instancing by adding a per-vertex XMFLOAT3X4 transform matrix.

The ctor can throw std::bad_alloc or std::runtime_error if the Direct3D feature level is lower than 10.0.

The method SetMode can throw std::invalid_argument.

The other property methods of this implementation do not throw C++ exceptions.

This effect uses Shader Model 4.0 so requires Direct3D hardware feature level 10.0 or greater.

Direct3D feature levels

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