#include <RixIntegrator.h>

Public Types
enum	RayType { k_rtInvalid = 0, k_rtCamera = 1, k_rtLight = 2, k_rtTransmission = 3, k_rtDirectlight = 4, k_rtIndirect = 5, k_rtNumRayTypes = 6 }

Public Member Functions
void	InitOrigination (RixShadingContext const sCtx, RtNormal3 const Ngn, int _shadingCtxIndex)
	`InitOrigination()` should be called after the ray geometry has been setup for calls to `GetNearestHits()`. More...

void	InitTransmitOrigination (RixShadingContext const *sCtx, int _shadingCtxIndex)
	`InitTransmission()` is analogous to `InitOrigination()` but should be used for transmission rays. More...

void	SetRaySpread (RixBXLobeSampled lobe, float rayOriginRadius, float rayOriginSpread, float curvature, float fPdf, bool lightPath=false)
	Computes ray spread for given reflection/transmission type, pdf, and surface curvature, using two approaches: More...

Static Public Member Functions
static PRMAN_INLINE uint16_t	EncodeWavelength (float wavelength)
	Converts a `wavelenght` (in nanometers) to a compact 16 bits representation of it. More...

static PRMAN_INLINE float	DecodeWavelength (uint16_t encodedWavelength)
	Converts from encoded 16 bits representation of wavelength to nanometers In both units 0 means "full spectrum", meaning no wavelength is defined. More...

Public Attributes
RtPoint3	origin

float	originRadius
	Ray origin. More...

RtVector3	direction
	Radius of ray at its origin. More...

float	raySpread
	Ray direction. More...

float	minDist
	How much the ray radius changes for each unit the ray travels. More...

float	maxDist
	Minimum hit distance. Used only for primary rays. More...

float	time
	Maximum hit distance. More...

uint16_t	raytype
	Shutter-normalized time of ray launch. More...

RixBXLobeSampled	lobeSampled
	See RayType for possible values. More...

RixShadingContext::Id	shadingCtxId
	Characteristics of the BxDF lobe this ray samples. More...

int16_t	integratorCtxIndex
	Shading context unique identifier. More...

uint16_t	shadingCtxIndex
	Associated primary ray index. More...

uint16_t	rayId
	Index into the lauching shading context. More...

RixLPEState *	lpeState
	User-provided index in the ray bundle. More...

uint32_t	private0 [5]
	A pointer to the LPE state for this ray launch. More...

float	opacityThreshold
	Data for internal use. More...

uint16_t	hitId
	This value is updated on each presence hit, whenever a surface with presence is hit. More...

uint16_t	flags
	Internal hit id, zero means 'no hit.'. More...

uint16_t	wavelength
	Flags for internal use. More...

uint16_t	ignoreGroupingId
	If non-zero: ignore geometry with the specified Attribute "grouping" "id". More...

Member Enumeration Documentation

◆ RayType

enum RtRayGeometry::RayType

Enumerator
k_rtInvalid
k_rtCamera
k_rtLight
k_rtTransmission
k_rtDirectlight
k_rtIndirect
k_rtNumRayTypes

Member Function Documentation

◆ DecodeWavelength()

static PRMAN_INLINE float RtRayGeometry::DecodeWavelength ( uint16_t encodedWavelength )

inlinestatic

Converts from encoded 16 bits representation of wavelength to nanometers In both units 0 means "full spectrum", meaning no wavelength is defined.

Parameters

[in] encodedWavelength A 16-bits encoded wavelength

Returns: the wavelength, in nanometers.

◆ EncodeWavelength()

static PRMAN_INLINE uint16_t RtRayGeometry::EncodeWavelength ( float wavelength )

inlinestatic

Converts a wavelenght (in nanometers) to a compact 16 bits representation of it.

In both units 0 means "full spectrum", meaning no wavelength is defined.

Parameters

[in] wavelength A wavelength in nanometers.

Returns: a 16-bits encoded wavelength.

◆ InitOrigination()

void RtRayGeometry::InitOrigination	(	RixShadingContext const *	sCtx,
		RtNormal3 const *	Ngn,
		int	_shadingCtxIndex
	)

inline

InitOrigination() should be called after the ray geometry has been setup for calls to GetNearestHits().

In addition to setting the origination context, we analyze the combination of lobeSampled and Nn to determine whether a transmit event was a nominal enter or exit. Origination state allows rays to be back-tracked to the original shading context for recovery of ray-path information.

Parameters

[in]	sCtx	Shading context containing the shading point that launched this ray.
[in]	Ngn	Geometric normal at the shading point that launched this ray.
[in]	_shadingCtxIndex	Index of the shading point in the shading context.

References RixBXLobeSampled::GetTransmit(), RixShadingContext::integratorCtxIndex, RixBXLobeSampled::SetEntering(), and RixShadingContext::shadingCtxId.

◆ InitTransmitOrigination()

void RtRayGeometry::InitTransmitOrigination	(	RixShadingContext const *	sCtx,
		int	_shadingCtxIndex
	)

inline

InitTransmission() is analogous to InitOrigination() but should be used for transmission rays.

All transmission 'events' are transmit events and lobeSampled is ill-defined (since lights are responsible for producing most transmission rays).

Parameters

[in]	sCtx	Shading context containing the shading point that launched this ray.
[in]	_shadingCtxIndex	Index of the shading point in the shading context.

References RixShadingContext::integratorCtxIndex, RixBXLobeSampled::Set(), RixBXLobeSampled::SetEntering(), and RixShadingContext::shadingCtxId.

◆ SetRaySpread()

void RtRayGeometry::SetRaySpread	(	RixBXLobeSampled	lobe,
		float	rayOriginRadius,
		float	rayOriginSpread,
		float	curvature,
		float	fPdf,
		bool	lightPath = `false`
	)

inline

Computes ray spread for given reflection/transmission type, pdf, and surface curvature, using two approaches:

Ray spread based on roughness (pdf). The ray spread from a flat rough surface depends on roughness: the higher roughness the lower the pdf in a given direction; here we map the pdf to a ray spread using a heuristic mapping.
Ray spread based on surface curvature. The ray spread for reflection from a curved smooth surface is simple to compute using Igehy's formula.

We set the overall ray spread to the max of these two. (For rough curved surfaces a better answer might be larger than the max – perhaps the sum? – but it's not 100% clear what the optimal combined value should be.)

Parameters

[in]	lobe	Used to determine if we are dealing with a reflection or transmission event.
[in]	rayOriginRadius	Incident ray radius at ray origin.
[in]	rayOriginSpread	Incident ray spread at ray origin.
[in]	curvature	Local surface curvature.
[in]	fPdf	Pdf associated with the ray direction.
[in]	lightPath	Indicates if the rays is part of a light path or not. Optional.

References RixBXLobeSampled::GetReflect(), RixBXLobeSampled::GetSolidAngle(), RixBXLobeSampled::GetTransmit(), and RixIsFinite().

Member Data Documentation

◆ direction

RtVector3 RtRayGeometry::direction

Radius of ray at its origin.

◆ flags

uint16_t RtRayGeometry::flags

Internal hit id, zero means 'no hit.'.

◆ hitId

uint16_t RtRayGeometry::hitId

mutable

This value is updated on each presence hit, whenever a surface with presence is hit.

The presence value will be compared against this threshold to decide if it is a hit or a miss.

◆ ignoreGroupingId

uint16_t RtRayGeometry::ignoreGroupingId

If non-zero: ignore geometry with the specified Attribute "grouping" "id".

◆ integratorCtxIndex

int16_t RtRayGeometry::integratorCtxIndex

Shading context unique identifier.

◆ lobeSampled

RixBXLobeSampled RtRayGeometry::lobeSampled

See RayType for possible values.

◆ lpeState

RixLPEState* RtRayGeometry::lpeState

User-provided index in the ray bundle.

◆ maxDist

float RtRayGeometry::maxDist

Minimum hit distance. Used only for primary rays.

◆ minDist

float RtRayGeometry::minDist

How much the ray radius changes for each unit the ray travels.

Use as is to get tex/env filter radii. Multiply by 2 to get footprints and tex/env filter diameters. Values range between 0 and 1 (where 1 corresponds to an angle of 45 degrees).

◆ opacityThreshold

float RtRayGeometry::opacityThreshold

Data for internal use.

◆ origin

RtPoint3 RtRayGeometry::origin

◆ originRadius

float RtRayGeometry::originRadius

Ray origin.

◆ private0

uint32_t RtRayGeometry::private0[5]

A pointer to the LPE state for this ray launch.

◆ rayId

uint16_t RtRayGeometry::rayId

Index into the lauching shading context.

◆ raySpread

float RtRayGeometry::raySpread

Ray direction.

◆ raytype

uint16_t RtRayGeometry::raytype

Shutter-normalized time of ray launch.

◆ shadingCtxId

RixShadingContext::Id RtRayGeometry::shadingCtxId

Characteristics of the BxDF lobe this ray samples.

◆ shadingCtxIndex

uint16_t RtRayGeometry::shadingCtxIndex

Associated primary ray index.

◆ time

float RtRayGeometry::time

Maximum hit distance.

◆ wavelength

uint16_t RtRayGeometry::wavelength

Flags for internal use.

Wavelength associated with the ray. See EncodeWavelength() and DecodeWavelength() methods. This quantity is then available on hits by querying the k_wavelength built-in primvar with RixShadingContext::GetBuiltinVar().

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

RixIntegrator.h

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Member Enumeration Documentation

◆ RayType

Member Function Documentation

◆ DecodeWavelength()

◆ EncodeWavelength()

◆ InitOrigination()

◆ InitTransmitOrigination()

◆ SetRaySpread()

Member Data Documentation

◆ direction

◆ flags

◆ hitId

◆ ignoreGroupingId

◆ integratorCtxIndex

◆ lobeSampled

◆ lpeState

◆ maxDist

◆ minDist

◆ opacityThreshold

◆ origin

◆ originRadius

◆ private0

◆ rayId

◆ raySpread

◆ raytype

◆ shadingCtxId

◆ shadingCtxIndex

◆ time

◆ wavelength