aperture
restricts the propagation of light rays

x- double x position of the center in world units
opening- double the opening size as a fraction from 0 to 1.0.

beamstop
restricts the propagation of light rays

x- double x position of the center in world units
bottom- double position of bottom as a fraction from 0 to 1.0.
top- double position of top as a fraction from 0 to 1.0.

bench
a placeholder for the optic elements

No attributes.  Use this parameter to determine the drawing order for the optic elements relative to the geometric objects.

box

A hollow rectangle.

x- double x position of the center in world units
y- double y position of the center in world units
h- int height in pixels
w- int width in pixels
s-int thickness of the box

circle

x- double x position of the center in world units
y- double y position of the center in world units.
r- int radius in pixels

constraint

xmin- double The minimum x value.
xmax- double The maximum x value.
ymin- double The minimum y value.
ymax- double The maximum y value.

A constraint, by itself, will have no effect.  It must be attached to a dragable object using the setConstriant method.

dielectric

x- double x position of the center in world units.
dn- double the change in index of refraction.
r- double radius or curvature of the index change

Models and change in index of refraction using Snell's law.  Aberrations are observed. See also refraction.

image 
a gif image

x- double x position of the center in world units
y- double y position of the center in world units.
gif- string a gif image
file- string same as gif

OpticsApplet will search for images in the code-base directory.  This is the directory containing the jar files.
You may use subdirectories relative to the code-base to organize images.
Example: addObject("image","file=optics/eye.gif");

lens

x- double x position of the center in world units.
f- double the focal length  
Example:  addObject("lens","x=1, f=-2");

matrix
transformation functions

x- double x position in world units.
height- double the height transformation:  H(h,a)
angle- double the angle transformation: A(h,a)
Transformation functions are analytic functions of height and angle, h and a, respectively.

mirror

x- double x position of the center in world units.
f- double the focal length
spherical  include spherical aberrations
Example: addObject("mirror","x=1, f=-2, spherical");

x- double x position of the vertex in world units
y- double y position of the vertex in world units.
s- int base size in pixel
theta- double vertex interior angle
theta0- double vertex base angle
fixedbase- fixes the base angle
fixedsize- fixes the length of the arm

rectangle

x- double x position of the center in world units
y- double y position of the center in world units
h- int height in pixels
w- int width in pixels

refraction

x- double x position of the center in world units.
dn- double the change in index of refraction.
r- double radius or curvature of the index change

Models and change in index of refraction using the small angle approximation. See also dielectric.

screen

x- double x position of the center in world units

shell

x- double x position of the center in world units
y- double y position of the center in world units
r- int radius in pixels

source

x- double x position of the center in world units.
y- double y position of the center in world units.

Choose either infinite or point selectors.  The three principle rays will be drawn if neither selector is specified.

 infinite  a beam of parallel light rays
    s- int the size of the beam in pixels.
    nrays- int the number of rays

point  a beam of parallel light rays
    slope- double the slope of the rays.  -1<angle<1
    inc- double the slope increment between rays.

Examples:
addObject("source","x=1, point, inc=0.1, slope=1.0":
addObject("source","x=1, infinite, s=30, nrays=20");

text

A fixed text string followed by an optional calculation.

x- double x position of the left side of the text in world units
y- double y position of the top of the text in world units
text- string static text.
calc- string An analytic function to be evaluated.  The calculation is displayed to the right of the static text.

Text objects are often slaved to other objects.  If a text object is slaved to a wire, it takes on the properties of that wire and can evaluate a function of t, x, y, flux, and v. Note:  Use the setFormat method described to change the decimal format used to output the calculation.