NPREffect

DirectXTK	Effects

NPREffect implements non-photorealistic rendering techniques such as cel shading, Gooch shading, and MatCap (material capture) rendering. It provides an optional rim-lighting Fresnel effect for cel and Gooch shading modes.

SkinnedNPREffect extends NPREffect to support vertex skinning. The skinned effect does not support per-vertex colors or GPU instancing. Texturing is always enabled for the skinned effect as well.

See also NPREffectFactory

classDiagram
class IEffect{
    <<Interface>>
    +Apply()
    +GetVertexShaderBytecode()
}
class IEffectMatrices{
    <<Interface>>
    +SetWorld()
    +SetView()
    +SetProjection()
    +SetMatrices()
}
class IEffectLights{
    <<Interface>>
    +SetLightDirection()
    +EnableDefaultLighting()
}
class NPREffect{
    +SetMode()
    +SetAlpha()
    +SetDiffuseColor()
    +SetSpecularColor()
    +SetSpecularThreshold()
    +SetCelShaderBands()
    +SetGoochCoolColor()
    +SetGoochWarmColor()
    +SetRimLightingColor()
    +SetTextureEnabled()
    +SetVertexColorEnabled()
    +SetBiasedVertexNormals()
    +SetInstancingEnabled()
}
NPREffect--|> IEffect
NPREffect--|> IEffectMatrices
NPREffect--|> IEffectLights
class IEffectSkinning{
    <<Interface>>
    +SetBoneTransforms()
    +ResetBoneTransforms()
}
class SkinnedNPREffect
NPREffect <|-- SkinnedNPREffect
SkinnedNPREffect --|> IEffectSkinning

Loading

class DirectX::NPREffect :
    public DirectX::IEffect,
    public DirectX::IEffectMatrices,
    public DirectX::IEffectLights

class DirectX::SkinnedNPREffect :
    public DirectX::NPREffect,
    public DirectX::IEffectSkinning

Header

#include <Effects.h>

Initialization

Construction requires a Direct3D 11 device.

std::unique_ptr<NPREffect> effect;
effect = std::make_unique<NPREffect>(device);

std::unique_ptr<SkinnedNPREffect> effect;
effect = std::make_unique<SkinnedNPREffect>(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

Interfaces

NPREffect supports IEffect, IEffectMatrices, and IEffectLights.

Lighting is always enabled and MaxDirectionalLights is 1.

SkinnedNPREffect also supports IEffectSkinning

Fog settings are not supported.

Input layout

This effect requires SV_Position, NORMAL, COLOR if per-vertex colors are enabled, and TEXCOORD0 if texturing or matcap is enabled.

If instancing is enabled, NPREffect also requires these vertex elements:

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

If skinning is used, the vertex layout requires BLENDINDICES and BLENDWEIGHT.

Properties

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

Mode_Cel	Cel shading (a.k.a. toon shading)
Mode_Gooch	Gooch shading (warm/cool technical illustration)
Mode_MatCap	Material capture rendering (lit-sphere texture)

• SetDiffuseColor: Sets the diffuse color of the effect. Defaults to white (1,1,1). Alpha channel (.w component) is ignored.

• SetSpecularColor: Sets the specular color of the effect. Defaults to white (1,1,1).

• SetSpecularThreshold: Sets the specular threshold and smoothing value for the effect. Both values must be in the 0 to 1 range. Note that this is a linear value between 0 and 1 and not a Phong power value.

• DisableSpecular: Disables the specular lighting for the effect.

• SetAlpha: Sets the alpha (transparency) of the effect. Defaults to 1 (fully opaque). This value is also used for binning opaque vs. transparent geometry.

• SetColorAndAlpha: Sets the diffuse color of the effect and the alpha (transparency).

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

• SetTextureEnabled: Enables texturing. Defaults to false. Modifying this setting requires recreating associated input layouts, and enabling it requires TEXCOORD0.

• SetTexture: Associates a texture shader resource view with the effect. Can be set to nullptr to remove a reference. Can optionally include an alpha channel as well.

• 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.

Cel/toon shading

• SetCelShaderBands: Sets the number of cel bands when rendering. Defaults to 4.

Gooch shading

• SetGoochCoolColor: Sets the 'cool' color for Gooch shading and alpha weight.

• SetGoochWarmColor: Sets the 'warm' color for Gooch shading and beta weight.

MatCap rendering

• SetMatCap: Sets the material capture (matcap) texture to use when rendering in this mode. Uses the same texture coordinates as texturing (i.e. TEXCOORD0).

RimLighting

• SetRimLightingColor: Sets the rim-lighting color. Defaults to black (0,0,0).

• SetRimLightingPower: Sets the rim-lighting power. Defaults to 4.

• SetRimLightingIntensity: Sets a multiplier for the rim-lighting effect in the range of 0 to 1. Defaults to 0.75.

• SetRimLightingRange: Sets the rim-lighting range between 0 and 1. Defaults to [0.2, 0.6].

• DisableRimLighting: Disables the rim-lighting effect.

Applies to both Cel/toon and Gooch shading, but not MatCap.

Exceptions

The ctor can throw std::bad_alloc.

The methods SetSpecularThreshold, SetMode, SetCelShaderBands, SetRimLightingIntensity, SetRimLightingRange can throw std::invalid_argument.

For SkinnedNPREffect, calling SetTextureEnabled(false), SetVertexColorEnabled(true), or SetInstancingEnabled(true) will throw std::invalid_argument.

Remarks

The cel and Gooch shading always uses 1 directional light, and material capture lighting all comes from the matcap texture.

SetLightingEnabled, SetPerPixelLighting, SetAmbientLightColor, SetLightEnabled, SetLightDiffuseColor, and SetLightSpecularColor are not implemented by this effect.

Further reading

Unity Shaders|MatCap casestudy
MatCap Library on GitHub