visutwin::canvas::EnvLighting Class Reference

#include <scene/graphics/envLighting.h>

Static Public Member Functions
static Texture *	generateAtlas (GraphicsDevice *device, Texture *source, int size=512, int numReflectionSamples=1024, int numAmbientSamples=2048)
static std::vector< uint8_t >	generateAtlasRaw (const float *srcData, int srcW, int srcH, int size=512, int numReflectionSamples=1024, int numAmbientSamples=2048)
static Texture *	generateSkyboxCubemap (GraphicsDevice *device, Texture *source, int size=0)

Detailed Description

Helper class to support prefiltering lighting data.

Generates a 512x512 RGBP environment atlas from an HDR equirectangular source texture. The atlas layout matches what the Metal shader's mapRoughnessUv() / decodeRGBP() consume:

Mipmaps section (cubemap -> equirect, direct resample): level 0: rect(0, 0, 512, 256) level 1: rect(256, 256, 256, 128) level 2: rect(384, 384, 128, 64) level 3: rect(448, 448, 64, 32) level 4: rect(480, 480, 32, 16) level 5: rect(496, 496, 16, 8) level 6: rect(504, 504, 8, 4)

Reflections section (GGX prefiltered): blur 1: rect(0, 256, 256, 128) specularPower=512 blur 2: rect(0, 384, 128, 64) specularPower=128 blur 3: rect(0, 448, 64, 32) specularPower=32 blur 4: rect(0, 480, 32, 16) specularPower=8 blur 5: rect(0, 496, 16, 8) specularPower=2 blur 6: rect(0, 504, 8, 4) specularPower=1

Ambient section (Lambert irradiance): rect(128, 384, 64, 32)

Definition at line 48 of file envLighting.h.

Member Function Documentation

generateAtlas()

Texture * visutwin::canvas::EnvLighting::generateAtlas ( GraphicsDevice * device, Texture * source, int size = 512, int numReflectionSamples = 1024, int numAmbientSamples = 2048 )

static

Generate a 512x512 RGBP atlas from an HDR equirectangular texture.

Parameters

device	GraphicsDevice for texture creation.
source	RGBA32F equirectangular texture loaded from .hdr file.
size	Output atlas size (default 512).
numReflectionSamples	Samples for GGX convolution (default 1024).
numAmbientSamples	Samples for Lambert convolution (default 2048).

Returns

Newly created RGBA8 RGBP-encoded atlas texture.

Definition at line 742 of file envLighting.cpp.

References visutwin::canvas::FILTER_LINEAR, visutwin::canvas::TextureOptions::format, visutwin::canvas::Texture::getLevel(), visutwin::canvas::Texture::height(), visutwin::canvas::TextureOptions::height, visutwin::canvas::TextureOptions::magFilter, visutwin::canvas::TextureOptions::minFilter, visutwin::canvas::TextureOptions::mipmaps, visutwin::canvas::TextureOptions::name, visutwin::canvas::PIXELFORMAT_RGBA8, visutwin::canvas::RGBP, visutwin::canvas::Texture::width(), and visutwin::canvas::TextureOptions::width.

generateAtlasRaw()

std::vector< uint8_t > visutwin::canvas::EnvLighting::generateAtlasRaw ( const float * srcData, int srcW, int srcH, int size = 512, int numReflectionSamples = 1024, int numAmbientSamples = 2048 )

static

CPU-only atlas generation from raw RGBA32F equirectangular pixel data. Returns a vector of RGBA8 RGBP-encoded pixels (size*size*4 bytes). No GraphicsDevice or Texture objects required.

Parameters

srcData	RGBA32F interleaved pixel data (4 floats per pixel).
srcW	Source width in pixels.
srcH	Source height in pixels.
size	Output atlas size (default 512).
numReflectionSamples	Samples for GGX convolution (default 1024).
numAmbientSamples	Samples for Lambert convolution (default 2048).

Definition at line 862 of file envLighting.cpp.

generateSkyboxCubemap()

Texture * visutwin::canvas::EnvLighting::generateSkyboxCubemap ( GraphicsDevice * device, Texture * source, int size = 0 )

static

Generate a high-resolution cubemap from an HDR equirectangular source. EnvLighting.generateSkyboxCubemap()

The cubemap is used for rendering the skybox at full source resolution, while the envAtlas (512x512) is used only for PBR lighting (reflections/ambient).

Parameters

device	GraphicsDevice for texture creation.
source	RGBA32F equirectangular texture loaded from .hdr file.
size	Cubemap face size. 0 = auto (source.width / 4).

Returns

Newly created RGBA8 cubemap texture (6 faces, no mipmaps).

Definition at line 941 of file envLighting.cpp.

References visutwin::canvas::TextureOptions::cubemap, visutwin::canvas::FILTER_LINEAR, visutwin::canvas::TextureOptions::format, visutwin::canvas::Texture::getLevel(), visutwin::canvas::Texture::height(), visutwin::canvas::TextureOptions::height, visutwin::canvas::TextureOptions::magFilter, visutwin::canvas::TextureOptions::minFilter, visutwin::canvas::TextureOptions::mipmaps, visutwin::canvas::TextureOptions::name, visutwin::canvas::PIXELFORMAT_RGBA8, visutwin::canvas::RGBP, visutwin::canvas::Texture::width(), and visutwin::canvas::TextureOptions::width.

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The documentation for this class was generated from the following files:

• scene/graphics/envLighting.h
• scene/graphics/envLighting.cpp