Содержание

DirectXTK	Effects

PBREffect implements a Disney-style (Roughness/Metalness workflow) Physically-Based Renderer (PBR) effect using Image-Based Lighting (IBL) in combination with up to three directional lights. This effect also supports GPU instancing.

SkinnedPBREffect extends PBREffect to support vertex skinning. The skinned effect does not support velocity buffer generation or GPU instancing.

Header

#include <Effects.h>

Initialization

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

std::unique_ptr<PBREffect> effect;

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

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

effect = std::make_unique<PBREffect>(device, EffectFlags::None, pd);

std::unique_ptr<SkinnedPBREffect> effect;
effect = std::make_unique<SkinnedPBREffect>(device, EffectFlags::None, pd);

In addition to the usual effect flags, this effect also supports EffectFlags::Emissive and EffectFlags::Velocity.

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

Older versions of the library used , bool emissive = false, bool generateVelocity = false) as the final parameters to the ctor. These are replaced with EffectFlags now.

Interfaces

PBREffect supports IEffect, IEffectMatrices, and IEffectLights.

SkinnedPBREffect also supports IEffectSkinning.

Fog settings are not supported by these effects.

Input layout

These effects require SV_Position, NORMAL, and TEXCOORD0.

If instancing is enabled (EffectFlags::Instancing), PBREffect 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

SetAlpha: Sets the alpha (transparency) of the effect. Defaults to 1 (fully opaque). This value is also used for binning opaque vs. transparent geometry.
SetConstantAlbedo, SetConstantMetallic, and SetConstantRoughness: Used to set the constant value when not using texturing for the albedo, roughness, and metalness information.
SetAlbedoTexture: Sets the albedo texture along with a sampler descriptor with the effect. Can optionally include an alpha channel as well.
SetNormalTexture: Sets the normal texture. Uses the same sampler as the albedo texture.

See NormalMapEffect for more details about the normal map texture.

SetRMATexture: Sets the roughness/metalness/ambient-occlusion (RMA) texture. Uses the same sampler as the albedo texture.

The RMA texture uses the glTF2 standard order: The metalness is in the B channel, roughness in the G channel, and ambient occlusion in the R channel. If there's no ambient occlusion, then the R channel should be set to all 1.

SetEmissiveTexture: Associates an emissive texture with the effect. Uses the same sampler as the albedo texture. This requires having enabled EffectFlags::Emissive in the constructor, otherwise it is ignored.
SetSurfaceTextures: Associates a albedo texture, normal texture, and roughness/metalness/ambient-occlusion (RMA) texture along with a sampler descriptor with the effect in one method.
SetIBLTextures: Associates a radiance and irradiance texture along with a sampler descriptor with the effect. The number of miplevels in the radiance texture is also required as this is used to compute roughness.

The radiance and irradiance map are special cubemaps. They are generated by tools like AMD Cubemapgen, cmft/cmftStudio, IBLBaker, and Lys.

SetRenderTargetSizeInPixels: Used to set the pixel size of the render target when generating velocity buffers. If EffectFlags::Velocity is set, then both a Render Target 0 and Render Target 1 must be bound for rendering, and SetRenderTargetSizeInPixels should be set for the target pixel size.

Remarks

If EffectFlags::Texture is not provided, then the effect uses the constant albedo, metallic, and roughness values. Note that use of velocity buffers require texture input.

The EffectFlags::Lighting and EffectsFlags::PerPixelLighting are always enabled for these effects, so use or absence of these flag is ignored.

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

EffectFlags::Fog and EffectFlags::VertexColor are not supported by these effects.

PBREffect does not support both EffectFlags::Instancing and EffectFlags::Velocity at the same time. SkinnedPBREffect doesn't support either of these effect flags.