

PREV CLASS NEXT CLASS  FRAMES NO FRAMES  
SUMMARY: NESTED  FIELD  CONSTR  METHOD  DETAIL: FIELD  CONSTR  METHOD 
public interface Shader
A Shader
instance represents a surface shader which
calculates the color of an outgoing light ray at a given point
as a function of geometrical and optical properties,
namely local and global point coordinates, canonical uvcoordinates, surface
tangent vectors, outgoing ray direction, index of refraction,
and a list of incident light rays, consisting of color and direction.
Field Summary  

static float 
LAMBERTIAN_VARIANCE
The angular variance of a lambertian reflector, (π^{2}  4) / 8. 
Fields inherited from interface de.grogra.ray.physics.Scattering 

DELTA_FACTOR, IS_NON_OPAQUE, MIN_UNUSED_FLAG, NEEDS_NORMAL, NEEDS_POINT, NEEDS_TANGENTS, NEEDS_TRANSFORMATION, NEEDS_UV, RANDOM_RAYS_GENERATE_ORIGINS 
Method Summary  

void 
computeMaxRays(Environment env,
Vector3f in,
Spectrum specIn,
Ray reflected,
Tuple3f refVariance,
Ray transmitted,
Tuple3f transVariance)
Computes, for the given input, the reflected and transmitted importance rays for which the reflection/transmission probability densities (integrated over the spectrum) attain a maximum. 
boolean 
isTransparent()

void 
shade(Environment env,
RayList in,
Vector3f out,
Spectrum specOut,
Tuple3d color)
Computes color of outgoing light ray for given input. 
Methods inherited from interface de.grogra.ray.physics.Scattering 

computeBSDF, generateRandomRays, getAverageColor, getFlags 
Field Detail 

static final float LAMBERTIAN_VARIANCE
computeMaxRays(de.grogra.ray.physics.Environment, javax.vecmath.Vector3f, de.grogra.ray.physics.Spectrum, de.grogra.ray.util.Ray, javax.vecmath.Tuple3f, de.grogra.ray.util.Ray, javax.vecmath.Tuple3f)
,
Constant Field ValuesMethod Detail 

void computeMaxRays(Environment env, Vector3f in, Spectrum specIn, Ray reflected, Tuple3f refVariance, Ray transmitted, Tuple3f transVariance)
in
, is
in
) / R
in
).
The transmission probability density is defined correspondingly.
The color
fields are set to the total
reflectivity/transparency for the incident direction
for each color component R, G, B. Thus, for physically plausible
BRDF/BTDF, the componentwise sum of reflected.color
and
transmitted.color
lies in the interval [0, 1],
and the difference to 1 is the amount absorbed.
The color
may be zero if there is no reflected or transmitted ray,
respectively, i.e., if the surface is fully transparent, opaque,
or absorbing. The originfields of the rays will never be set.
The computed variances are defined to be, for each color component,
(approximations for) the angular mean quadratic
deviations of the densities from the returned maximal ray directions.
E.g., for perfect reflection/transmission, these variances are zero,
whereas for a perfect lambertian reflector, the variance of reflection
is ∫ cos θ (1 / π) θ^{2} dω
= (π^{2}  4) / 8.
This is the value of LAMBERTIAN_VARIANCE
.
The ray properties which are not mentioned are neither used nor modified. These are the origin and its density, and the direction density.
env
 the environment for scatteringin
 the (negated) direction unit vector of the incoming ray
(i.e., pointing away from the surface)specIn
 spectrum of incoming rayreflected
 the reflected ray with maximal probabilityrefVariance
 the angular mean quadratic deviation from reflected
transmitted
 the transmitted ray with maximal probabilitytransVariance
 the angular mean quadratic deviation from transmitted
boolean isTransparent()
void shade(Environment env, RayList in, Vector3f out, Spectrum specOut, Tuple3d color)
out
) c_{k,j}
env.point
,
ω_{k} and c_{k} the direction and color of ray k,
and θ_{k} the angle between the surface normal
and ω_{k}.
The computation may include physically invalid contributions, which may not fit into the formula above, e.g., ambient or emissive light contributions.
env
 the environment for scatteringin
 the incoming raysout
 the direction unit vector of the outgoing ray
(i.e., pointing away from the surface)specOut
 spectrum of outgoing raycolor
 the output color will be placed in here


PREV CLASS NEXT CLASS  FRAMES NO FRAMES  
SUMMARY: NESTED  FIELD  CONSTR  METHOD  DETAIL: FIELD  CONSTR  METHOD 