Common parameters of photon mapping. More...

#include <PMCommonParams.h>

Public Attributes
std::size_t	numPhotons = 200000

std::size_t	numPasses = 1

std::size_t	numSamplesPerPixel = 4

real	kernelRadius = 0.1_r

uint32	minPhotonPathLength = 1

uint32	maxPhotonPathLength = DEFAULT_MAX_PATH_LENGTH

real	alpha = 2.0_r / 3.0_r

uint32	glossyMergeBeginLength = 1

uint32	stochasticViewSampleBeginLength = 3

Static Public Attributes
static constexpr uint32	DEFAULT_MAX_PATH_LENGTH = 16384

Detailed Description

Common parameters of photon mapping.

Member Data Documentation

◆ alpha

real ph::PMCommonParams::alpha = 2.0_r / 3.0_r

Controls the kernel radius reduction rate for progressive techniques. Smaller value has higher radius reduction rate (higher variance/noise, smaller expected error/bias), larger value has lower radius reduction rate (lower variance/noise, higher expected error/bias). Alpha effectively determines a trade-off between noise and bias. The value should be within (0, 1).

◆ DEFAULT_MAX_PATH_LENGTH

uint32 ph::PMCommonParams::DEFAULT_MAX_PATH_LENGTH = 16384

inlinestaticconstexpr

◆ glossyMergeBeginLength

uint32 ph::PMCommonParams::glossyMergeBeginLength = 1

Hint for the minimum path length to start estimating energy using photons on glossy surface. If the scene contains diffuse surface and is easily reachable by photons, it is recommended to set this to a lower value.

◆ kernelRadius

real ph::PMCommonParams::kernelRadius = 0.1_r

Energy contribution radius for each photon. For progressive techniques, this value is for setting up the initial radius.

◆ maxPhotonPathLength

uint32 ph::PMCommonParams::maxPhotonPathLength = DEFAULT_MAX_PATH_LENGTH

Maximum path length for a photon. The default value is effectively infinite bounces. Combined with minPhotonPathLength, these parameters are useful if only some number of bounces are estimated via photons.

◆ minPhotonPathLength

uint32 ph::PMCommonParams::minPhotonPathLength = 1

Minimum path length for a photon. Photon with 0 path length is not supported, as it is like approximating emissive surface with photons and the result is overly blurry for no good reason. 0-bounce lighting is done via traditional path sampling.

◆ numPasses

std::size_t ph::PMCommonParams::numPasses = 1

Number of passes performed by progressive techniques.

◆ numPhotons

std::size_t ph::PMCommonParams::numPhotons = 200000

Number of photons used. For progressive techniques, this value is for a single pass.

◆ numSamplesPerPixel

std::size_t ph::PMCommonParams::numSamplesPerPixel = 4

Number of samples per pixel. Higher values can resolve image aliasing, but can consume large amounts of memory for some algorithms. This value can also mean the number of statistics gathered in a single pixel for some techniques. If the value is not a power-of-2 number, it may be adjusted.

◆ stochasticViewSampleBeginLength

uint32 ph::PMCommonParams::stochasticViewSampleBeginLength = 3

Hint for the view path length to start random path sampling. If this value differ too much from the mean specular path length from the scene, the energy estimation result may contain higher variance or bias. Beware when using higher values as non-stochastic path may be branched, which can result in exponential growth of number of rays.

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

Source/Core/Renderer/PM/PMCommonParams.h

Public Attributes

Static Public Attributes