CylindricalEnvironment Class Reference

A class for Lambert Equal-Area Cylindrical environment maps. More...

#include <lightshaders/CylindricalEnvironment.h>

Inheritance diagram for CylindricalEnvironment:

[legend]List of all members.

Public Member Functions
	CylindricalEnvironment (const Image *image)
void	estimateRadiance (const HitRecord &rec, Context &context, Vector3 &w_in, double &distance, rgb &radiance) const
rgb	estimateBGRadiance (const HitRecord &rec, const Vector3 &w_in, Context &context) const
bool	sampleDirection (const HitRecord &rec, Context &context, Vector3 &w_in, double &pdf) const
double	pdfDirection (const Vector3 &w_in, const HitRecord &rec, Context &context) const
rgb	value (const Vector3 &direction) const
void	directionToUV (const Vector3 &direction, unsigned int &u, unsigned int &v) const
	given a direction, find the image coordinates (u,v)
Vector3	UVtoDirection (unsigned int u, unsigned int v) const
	given a pixel, find the corresponding direction
Public Attributes
EnvironmentSampler *	env_sampler
	EnvironmentSampler for looking up probabilities and generating samples.
const Image *	environment
	The actual environment map image.
unsigned int	w
	stored width and height of the image (for performance)
unsigned int	h

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Detailed Description

A class for Lambert Equal-Area Cylindrical environment maps.

Todo:

Remove the attempt to open a filename (take an image instead)

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Member Function Documentation

void CylindricalEnvironment::estimateRadiance (  const HitRecord &  rec, Context &  context, Vector3 &  w_in, double &  distance, rgb &  radiance )  const [virtual]

Estimate the radiance this light deposits towards a point in the scene. The light should not attempt an intersection with the scene to determine if an occlusion exists. Occlusion testing can be performed by the caller with the retured 'w_in' and 'distance'. Singular light sources, such as point lights, would only implement this function and allow the caller to test for occlusion. LightShaders intended for area lights may also implement this function as it may allow for importance sampling of luminaires based on estimated radiance. Parameters: [in]  rec  HitRecord for the point asking for a radiance estimate. [in]  context  The standard rendering context. [out]  w_in  The unit length vector to the light. [out]  distance  Distance from the shading point to the light. [out]  radiance  The radiance estimate. Reimplemented from LightShader.

rgb CylindricalEnvironment::estimateBGRadiance (  const HitRecord &  rec, const Vector3 &  w_in, Context &  context )  const [virtual]

Estimate the radiance this light produces along the ray given by the input direction and the hit point in rec. This function is intended for background environments and should be called for rays that leave the scene without intersecting any geometry. Parameters: [in]  rec  HitRecord for the point being lit. [in]  w_in  Unit length vector towards the light. [in]  context  The standard rendering context. Returns: rgb value representing the incident radiance. Reimplemented from LightShader.

bool CylindricalEnvironment::sampleDirection (  const HitRecord &  rec, Context &  context, Vector3 &  w_in, double &  pdf )  const [virtual]

Attempt to generate a directional sample towards this light source. Parameters: [in]  rec  The HitRecord for the point being lit. [in]  context  The standard rendering context. [out]  w_in  Unit length vector pointing towards the light source. [out]  pdf  The value of the pdf for this vector. Returns: True if a sample was generated. Reimplemented from LightShader.

double CylindricalEnvironment::pdfDirection (  const Vector3 &  w_in, const HitRecord &  rec, Context &  context )  const [virtual]

Evaluate the pdf of generating the sampled direction. Parameters: [in]  w_in  Unit length vector. [in]  rec  The HitRecord of the point being lit. [in]  context  The standard rendering context. Returns: Evaluation of the pdf for the direction. Reimplemented from LightShader.

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

• CylindricalEnvironment.h
• CylindricalEnvironment.cc

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