slr::SlrShadingContext Class Reference

#include <SlrShadingContext.h>

Public Member Functions
	SlrShadingContext ()
	Default ctor leaves junk in most vars, sets pointers to null.
void	set (const SlrShadingContext &currentStx, const ndk::RayContext &Rtx)
	Copies currentStx and params and updates the srcRtx.
void	set (const SlrShadingContext &currentStx, const fdk::Vec3f &Rdir, double tMin, double tMax, const ndk::RayContext::TypeMask &Rtype, uint32_t sides_mode)
	Copies currentStx and params and updates the srcRtx.
fdk::TimeValue	time () const
	Absolute time of the context.
SlrThreadContext *	sttx () const
	SlrThreadContext which 'owns' this shading context.
uint32_t	threadIdx () const
	Thread index from current SlrThreadContext.
const SlrShadingContext *	previousStx () const
	Previous SlrShadingContext, normally the last surface intersected/shaded.
bool	blendBackToFront () const
	Blending Z order is back-to-front (true) or front-to-back (false)
bool	enableColorChannels () const
	Shaders should output color layers + alphas.
bool	enableDataChannels () const
	Shaders should output any data channels (Z, etc)
bool	textureSamplingEnabled () const
void	setTextureSampling (bool enabled)
void	enableTextureSampling ()
void	disableTextureSampling ()
DD::Image::TextureFilter *	textureFilter () const
	Texture filter to use.
bool	lightingEnabled () const
	If true, even if no lights the surface shaders should do illum calcs.
bool	directLightingEnabled () const
	If true do direct-illumination calculations.
bool	indirectLightingEnabled () const
	If true handle indirect-illumation calculations.
bool	shadowingEnabled () const
	If true do shadow occlusion for direct-illumination.
bool	useHeroCamForSpec () const
	If enabled getViewVector() uses camHeroP() instead of camP().
const SlrTriangle *	rprim () const
const fdk::Mat4d *	l2w () const
	Local-to-world matrix for current primitive. If null assume xform is identity.
const fdk::Mat4d *	w2l () const
	World-to-local matrix for current primitive. If null assume xform is identity.
const fdk::Mat4d &	camWorld2Eye () const
	Render camera world-to-eye xform (world-space coords to camera local-space)
const fdk::Mat4d &	camEye2World () const
	Render camera eye-to-world xform (camera local-space coords to world-space)
const fdk::Vec3d &	camP () const
const fdk::Vec3d &	camHeroP () const
	Hero-view camera origin in world space - for specular copying.
const SlrLightInfoList &	lights () const
	List of active lights. If lightingEnabled is false an empty list is returned.
fdk::Vec3d	getViewVector () const
bool	shadeBothSides () const
	Shade both sides of surface (front and back) ignoring surface normal to camera.
bool	shadeFrontOnly () const
	Shade only front side of surface.
bool	shadeBackOnly () const
	Shade only front side of surface.
void	enableBothSidesMode ()
void	enableFrontSideMode ()
void	enableBackSideMode ()
const fdk::Vec3f &	ambientLightingBias () const
bool	intersect (const ndk::RayContext &Rtx) const
bool	getNearestIntersection (const ndk::RayContext &Rtx, SlrShadingContext &hitStx) const
float	getPolygonEdgeDistance (float minDist) const
const fdk::Vec2i &	pxy () const
	Current output screen coords.
const fdk::Vec2f &	sxy () const
	Current output subpixel screen coords.
int32_t	si () const
	Current subsample index.
bool	isDebugPixel () const
bool	isPixel (int32_t px, int32_t py) const
bool	isPixelX (int32_t px) const
bool	isPixelY (int32_t py) const
const fdk::Vec3f &	Ps () const
	Displaced shading point in common shading space where lighting is queried.
const fdk::Vec3f &	P () const
	Geometric point (intersection) in common shading space.
const fdk::Vec3f &	dPdx () const
	P differential for dyDir ray direction. ('dx' is the ray cone x-axis, not screen-space 'x')
const fdk::Vec3f &	dPdy () const
	P differential for dyDir ray direction. ('dy' is the ray cone y-axis, not screen-space 'y')
const fdk::Vec3f &	dPdu () const
	P surface u-space partial derivative, not normalized.
const fdk::Vec3f &	dPdv () const
	P surface v-space partial derivative, not normalized.
const fdk::Vec3f &	triUvw () const
const fdk::Vec2f	uv () const
	Surface 2D parametric coordinates of P.
const fdk::Vec2f	dUVdx () const
	Parametric-uv differential for dxDir ray direction.
const fdk::Vec2f	dUVdy () const
	Parametric-uv differential for dyDir ray direction.
float	uvw () const
	Surface Z parametric coordinate of P (for volumes)
float	dUVWdx () const
	Parametric-w differential for dxDir ray direction.
float	dUVWdy () const
	Parametric-w differential for dyDir ray direction.
const fdk::Vec2f &	st () const
	Surface texture st(uv) coordinate. st is assumed to have already been divided by any w.
const fdk::Vec2f &	dStdx () const
	Texture coord st differential for dxDir ray direction. ('dx' is the ray cone x-axis, not screen-space 'x')
const fdk::Vec2f &	dStdy () const
	Texture coord st differential for dyDir ray direction. ('dy' is the ray cone y-axis, not screen-space 'y')
const fdk::Vec2f &	dStdu () const
	St surface u-space partial derivative, not normalized.
const fdk::Vec2f &	dStdv () const
	St surface v-space partial derivative, not normalized.
const fdk::Vec3f &	N () const
	Shading normal, normalized.
const fdk::Vec3f &	Ng () const
	Geometric surface normal, normalized.
const fdk::Vec3f &	T () const
	Shading tangent, normalized.
const fdk::Vec4f &	Cf () const
	Interpolated vertex color + opacity.
const fdk::Vec4f &	rgba () const
const fdk::Vec3f &	rgb () const
float	r () const
float	g () const
float	b () const
float	a () const
float	opacity () const
void	sample (DD::Image::Sampler *sampler, DD::Image::Pixel &out) const
void	sample (DD::Image::Sampler *sampler, const Dual2Vec2f &v, DD::Image::Pixel &out) const
	Same as sample(Sampler*) but with overrides for st & derivatives currently in context.
void	sample (DD::Image::Iop *texture, DD::Image::Pixel &out) const
	Slower version using a raw Iop.
void	sample (DD::Image::Iop *texture, const Dual2Vec2f &v, DD::Image::Pixel &out) const
	Same as sample(Iop*) but with overrides for st & derivatives currently in context.
DD::Image::Pixel &	textureColor () const
	For sampling texture map Iops - defaults to RGBA.
DD::Image::Pixel &	bindingColor () const
	For Connection sampling calls - defaults to RGBA.
DD::Image::Pixel &	illumColor () const
	For LightShader evaluation - defaults to RGB.
DD::Image::Pixel &	shadowColor () const
	For LightShader shadow transmission evaluation - defaults to RGB (no depth!)
DD::Image::Pixel &	volumeColor () const
	For VolumeShader color evaluation - defaults to RGB.

Public Attributes
ndk::RayContext	srcRtx
	Ray that created this context.
int32_t	depth
	Current ray depth where 0 indicates a camera ray.
float	distance
	Distance of this context's P from srcRtx origin.
uint64_t	primId
	Unique ID of the current intersection renderable/subpart/subtri.
int32_t	renderableIndex
	PrimInfo index of current intersected object in SlrRenderContext.
SlrShadingParams	params
	Sampled surface parameters.
SlrSurfaceShader *	surfaceShader
	Current surface shader being evaluated.
SlrGeometryShader *	displacementShader
	Current displacement shader being evaluated, if any.
SlrVolumeShader *	atmosphereShader
	Current atmospheric volume shader being evaluated, if any.
float	_vP [28]
	Current values for shader - in homogeneous-space! (deprecated)
float	_vdX [28]
	Change if X of render pixel is increased by 1 (deprecated)
float	_vdY [28]
	Change if Y of render pixel is increased by 1 (deprecated)

Protected Attributes
SlrThreadContext *	_sttx
const SlrShadingContext *	_previousStx
	Previous SlrShadingContext, normally the last surface intersected/shaded.
int32_t	_sidesMode
	Which sides to intersect against and shade (use methods to query)
bool	_textureSampling
	Whether shaders should sample their textures.
DD::Image::TextureFilter *	_textureFilter
	Global texture filter to use.
const SlrObjectIntersection *	_If
	Intersection info.
SlrTriangle *	_rPrim
	Current render triangle being evaluated.
fdk::Mat4d *	_l2w
	Local-to-world object matrix for current primitive.
fdk::Mat4d *	_w2l
	World-to-local object matrix for current primitive.

Friends
class	SlrThreadContext
class	RenderEngine
class	RenderSpan
class	IntersectedSurfaces

Detailed Description

This class is intended to be passed up a SlrShader tree.

Member Function Documentation

textureSamplingEnabled()

bool slr::SlrShadingContext::textureSamplingEnabled ( ) const

inline

Should textures sample? This may be disabled for camera rays when shading a pre-rendered scene with pixel containing the surface albedo.

rprim()

const SlrTriangle * slr::SlrShadingContext::rprim ( ) const

inline

Render triangle currently being shaded. This can be tested against the rprim() in previousStx() to prevent self-intersection.

camP()

const Vec3d & slr::SlrShadingContext::camP

(

)

const

Render camera origin (camera rays originate here). Same as camEye2World().getTranslation(), but cached for speed.

References slr::SlrThreadContext::camP().

Referenced by getViewVector().

getViewVector()

fdk::Vec3d slr::SlrShadingContext::getViewVector

(

)

const

Returns a 'fake' stereo view vector built from the camHeroP, or the negated ray direction depending on context's stereo mode. By using the camHeroP camera-ray specular calculations are identical for all stereo cameras, 'flattening' the specular onto the surface.

References camHeroP(), camP(), depth, P(), and useHeroCamForSpec().

ambientLightingBias()

const Vec3f & slr::SlrShadingContext::ambientLightingBias

(

)

const

Adds light globally to the diffuse (albedo) surface response of surface shaders which respect this shading global.

intersect()

bool slr::SlrShadingContext::intersect

(

const ndk::RayContext &

Rtx

)

const

Returns true if anything is occluding the ray, including transparent objects. Does not call shaders or return information about the hit object.

References slr::SlrThreadContext::_objectsBvh.

getNearestIntersection()

bool slr::SlrShadingContext::getNearestIntersection	(	const ndk::RayContext &	Rtx,
		SlrShadingContext &	hitStx
	)		const

Intersect the scene with the RayContext Rtx, returning true if there was a hit within Rtx's distance range, and filling in hitStx with the information about the hit surface.

References _If, slr::SlrThreadContext::_intersectionInfo, slr::SlrThreadContext::_objectsBvh, and depth.

getPolygonEdgeDistance()

float slr::SlrShadingContext::getPolygonEdgeDistance

(

float

minDist

)

const

Distance from P to the nearest not-occluded polygon edge in screen-space for the current primitive. All triangles generated from the tessellation of the original SlrPrimInfo are tested, so the method checks all polygon edges. Returns when the first edge distance is under minDist.

References _If, slr::SlrThreadContext::_lensContext, slr::SlrThreadContext::_lensFunc, _rPrim, _vP, P(), and params.

triUvw()

const fdk::Vec3f & slr::SlrShadingContext::triUvw ( ) const

inline

Barycentric triangle uvw coordinates at srcRtx intersection. For a triangle with corners (p0 p1 p2) w=1 is along edge p0->p1, u=1 is along edge p1->p2, and v=1 is along edge p0->p2. If v or w are outside 0..1 then P is outside the bounds of the triangle and w in invalid. This happens when uvw is calculated for ray offsets dxDir & dyDir. They will always intersect the triangle plane but can often be outside the triangle's perimeter.

sample()

void slr::SlrShadingContext::sample	(	DD::Image::Sampler *	sampler,
		DD::Image::Pixel &	out
	)		const

Use st() and the derivatives of st() to sample the incoming image. The st coord 0,0 is mapped to the lower-left corner of the image's format, and 1,1 is mapped to the upper-right corner.

For texture sampling it's much faster to provide a DD::Image::Sampler rather than a raw Iop so Tile caching is properly leveraged.

References dStdu(), dStdv(), sample(), and st().

Referenced by sample().