org.sunflow.core

Class Ray


public final class Ray
extends java.lang.Object

This class represents a ray as a oriented half line segment. The ray direction is always normalized. The valid region is delimted by two distances along the ray, tMin and tMax.

Field Summary

float
dx
float
dy
float
dz
float
ox
float
oy
float
oz

Constructor Summary

Ray(float ox, float oy, float oz, float dx, float dy, float dz)
Creates a new ray that points from the given origin to the given direction.
Ray(Point3 a, Point3 b)
Creates a new ray that points from point a to point b.
Ray(Point3 o, Vector3 d)
Creates a new ray that points from the given origin to the given direction.

Method Summary

float
dot(float vx, float vy, float vz)
Computes the dot product of an arbitrary vector with the direction of the ray.
float
dot(Vector3 v)
Computes the dot product of an arbitrary vector with the direction of the ray.
Vector3
getDirection()
Creates a vector to represent the direction of the ray.
float
getMax()
Gets the maximum distance along the ray.
float
getMin()
Gets the minimum distance along the ray - usually 0.
Point3
getPoint(Point3 dest)
Gets the end point of the ray.
boolean
isInside(float t)
Checks to see if the specified distance falls within the valid range on this ray.
void
normalize()
Normalize the direction component of the ray.
void
setMax(float t)
Updates the maximum to the specified distance if and only if the new distance is smaller than the current one.
Ray
transform(Matrix4 m)
Create a new ray by transforming the supplied one by the given matrix.

Field Details

dx

public float dx

dy

public float dy

dz

public float dz

ox

public float ox

oy

public float oy

oz

public float oz

Constructor Details

Ray

public Ray(float ox,
           float oy,
           float oz,
           float dx,
           float dy,
           float dz)
Creates a new ray that points from the given origin to the given direction. The ray has infinite length. The direction vector is normalized.
Parameters:
ox - ray origin x
oy - ray origin y
oz - ray origin z
dx - ray direction x
dy - ray direction y
dz - ray direction z

Ray

public Ray(Point3 a,
           Point3 b)
Creates a new ray that points from point a to point b. The created ray will set tMin and tMax to limit the ray to the segment (a,b) (non-inclusive of a and b). This is often used to create shadow rays.
Parameters:
a - start point
b - end point

Ray

public Ray(Point3 o,
           Vector3 d)
Creates a new ray that points from the given origin to the given direction. The ray has infinite length. The direction vector is normalized.
Parameters:
o - ray origin
d - ray direction (need not be normalized)

Method Details

dot

public final float dot(float vx,
                       float vy,
                       float vz)
Computes the dot product of an arbitrary vector with the direction of the ray. This method avoids having to call getDirection() which would instantiate a new Vector object.
Parameters:
vx - vector x coordinate
vy - vector y coordinate
vz - vector z coordinate
Returns:
dot product of the ray direction and the specified vector

dot

public final float dot(Vector3 v)
Computes the dot product of an arbitrary vector with the direction of the ray. This method avoids having to call getDirection() which would instantiate a new Vector object.
Parameters:
v - vector
Returns:
dot product of the ray direction and the specified vector

getDirection

public final Vector3 getDirection()
Creates a vector to represent the direction of the ray.
Returns:
a vector equal to the direction of this ray

getMax

public final float getMax()
Gets the maximum distance along the ray. May be infinite.
Returns:
value of the largest distance along the ray

getMin

public final float getMin()
Gets the minimum distance along the ray - usually 0.
Returns:
value of the smallest distance along the ray

getPoint

public final Point3 getPoint(Point3 dest)
Gets the end point of the ray. A reference to dest is returned to support chaining.
Parameters:
dest - reference to the point to store
Returns:
reference to dest

isInside

public final boolean isInside(float t)
Checks to see if the specified distance falls within the valid range on this ray. This should always be used before an intersection with the ray is detected.
Parameters:
t - distance to be tested
Returns:
true if t falls between the minimum and maximum distance of this ray, false otherwise

normalize

public void normalize()
Normalize the direction component of the ray.

setMax

public final void setMax(float t)
Updates the maximum to the specified distance if and only if the new distance is smaller than the current one.
Parameters:
t - new maximum distance

transform

public Ray transform(Matrix4 m)
Create a new ray by transforming the supplied one by the given matrix. If the matrix is null, the original ray is returned.
Parameters:
m - matrix to transform the ray by