SkinnedEffect

DirectXTK	Effects

This is a native Direct3D 12 implementation of the built-in SkinnedEffect from XNA Game Studio 4 (Microsoft.Xna.Framework.Graphics.SkinnedEffect) which supports skinned animation with up to 72 bones and 1, 2, or 4 bone influences per vertex. It supports texture mapping, directional vertex lighting, directional per-pixel lighting, and fog.

See also Effects

Related tutorial:** Using skinned models

classDiagram
class EffectFlags{
    <<enumeration>>
    Fog
    PerPixelLighting
    BiasedVertexNormals 
}
class IEffect{
    <<Interface>>
    +Apply()
}
class IEffectMatrices{
    <<Interface>>
    +SetWorld()
    +SetView()
    +SetProjection()
    +SetMatrices()
}
class IEffectLights{
    <<Interface>>
    +SetAmbientLightColor()
    +SetLightEnabled()
    +SetLightDirection()
    +SetLightDiffuseColor()
    +SetLightSpecularColor()
    +EnableDefaultLighting()
}
class IEffectFog{
    <<Interface>>
    +SetFogStart()
    +SetFogEnd()
    +SetFogColor()
}
class IEffectSkinning{
    <<Interface>>
    +SetBoneTransforms()
    +ResetBoneTransforms()
}
class SkinnedEffect{
    +SetDiffuseColor()
    +SetEmissiveColor()
    +SetSpecularColor()
    +SetSpecularPower()
    +DisableSpecular()
    +SetAlpha()
    +SetColorAndAlpha()
    +SetTexture()
}
SkinnedEffect .. EffectFlags
SkinnedEffect --|> IEffect
SkinnedEffect --|> IEffectMatrices
SkinnedEffect --|> IEffectLights
SkinnedEffect --|> IEffectFog
SkinnedEffect --|> IEffectSkinning

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Header

#include <Effects.h>

Initialization

Construction requires a Direct3D 12 device, optional effect flags, and state description:

std::unique_ptr<SkinnedEffect> effect;

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

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

effect = std::make_unique<SkinnedEffect>(device, Effects::None, pd);

The constructor takes one additional optional parameter to optimize the shader (see below):

SkinnedEffect(ID3D12Device* device, int effectFlags,
    const EffectPipelineStateDescription& pipelineDescription, int weightsPerVertex = 4);

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

SkinnedEffect supports IEffect, IEffectMatrices, IEffectLights, IEffectFog, and IEffectSkinning. EffectFlags::Fog is required to enable fogging.

Input layout

This effect requires NORMAL, TEXCOORD0, BLENDINDICES and BLENDWEIGHT.

Properties

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

• SetEmissiveColor: Sets the emissive color of the effect. Defaults to black (0,0,0).

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

• SetSpecularPower: Sets the specular power of the effect. Defaults to 16. Settings power to 0 can cause strange rendering artifacts.

• DisableSpecular: Disables the specular lighting for the effect. Sets the color to black (0,0,0) and power to 1.

• 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).

• SetTexture: Associates a texture and sampler descriptor with the effect. Can optionally include an alpha channel as well.

Bone weights

The BLENDINDICES and BLENDWEIGHT elements can hold up to 4 individual bone influences per vertex. Since each influence adds more computation to the shader, you can optimize this effect by setting the supported number of influences to 1, 2, or 4 in the constructor and any additional influences will be ignored. This value defaults to 4.

Remarks

The effect always performs either vertex (EffectFlags::Lighting) or per-pixel lighting (EffectFlags::PerPixelLighting). It does not support per-vertex color (EffectFlags::VertexColor).

The EffectFlags::BiasedVertexNormals is supported by this effect. This flag should be used if the vertex data contains normals encoded as biased data such as DXGI_FORMAT_R10G10B10A2_UNORM.

This effect always performs texturing, so if 'untextured' rendering is desired you must provide texture coordinates, and a 1x1 texture with white (1,1,1,1).

Both EffectFlags::Lighting and EffectFlags::Texture are always enabled for this effect, so use or absence of these flags is ignored for this effect.