PBREffect

This effect 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.

Header

#include <Effects.h>

Initialization

Construction requires a Direct3D 11 device.

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

PBREffect supports IEffect, IEffectMatrices, and IEffectLights.

Fog settings are not supported by this effect.

Input layout

This effect requires SV_Position, NORMAL, and TEXCOORD0. It does not support per-vertex color.

Properties

SetAlpha: Sets the alpha (transparency) of the effect. Defaults to 1 (fully opaque).
SetConstantAlbedo, SetConstantMetallic, and SetConstantRoughness: Used to set the constant value when not using texturing for the roughness/metalness/ambient-occlusion information.
SetSurfaceTextures: Associates a albedo texture, normal texture, and roughness/metalness/ambient-occlusion (RMA) texture with the effect. This uses the sampler in slot 0. Can be set to nullptr to remove a reference.

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.

SetIBLTextures: Associates a radiance and irradiance texture with the effect. The number of miplevels in the radiance texture is also required as this is used to compute roughness. This uses the sampler in slot 1. Can be set to nullptr to remove a reference.

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

SetEmissiveTexture: Associates an emissive texture with the effect. This uses the sampler in slot 0. Can be set to nullptr to remove a reference.
SetBiasedVertexNormals: Enables support for compressed vertex normals which require *2 - 1 biasing at runtime such as DXGI_FORMAT_R10G10B10A2_UNORM.
SetVelocityGeneration: Enables the generation of a velocity buffer. If set to true, then both a Render Target 0 and Render Target 1 must be bound for rendering.
SetRenderTargetSizeInPixels: Used to set the pixel size of the render target when generating velocity buffers.

Remarks

This effect always performs per-pixel lighting. Calls to SetLightingEnabled(false); will generate a C++ exception, and calls to SetPerPixelLighting are ignored.

The lighting modeling for PBR does not make use of an ambient or specular term as these are more directly modeled by the image-based lighting model. Calls to SetAmbientLightColor and SetLightSpecularColor are ignored.

This effect requires a texture sampler in both slots 0 and 1. GeometricPrimitive and SpriteBatch only set a texture sampler in slot 0 by default, Model sets a sampler in slots 0 and 1.

Feature Level Notes

This effect uses Shader Model 4.0 so requires Direct3D hardware feature level 10.0 or greater. For this reason, the Windows Phone 8.1 projects do not include the source for the PBR effect implementation as Windows Phone 8.1 hardware only supports Feature level 9.3.

Direct3D feature levels