Introduction

•The source property, a type of surface property, specifies how a surface emits light. Other properties are used to identify special characteristics of a surface or object.

The details of how these properties are defined and how they can be changed are described in Chapter 3.

Applying Properties

In order for a TracePro model to behave properly when doing any type of ray tracing or analyses with your model, you will need to apply optical, mechanical and source properties to the appropriate objects and surfaces. A good way to get a quick preview of how properties are applied is to click on the Define|Apply Properties menu item. The Apply Properties dialog box will open with multiple screens accessible by clicking on the tabs. In Chapter 4 you will learn how to apply these properties.

Modeless Dialog Boxes

Many TracePro operations are performed using dialog boxes. Many TracePro dialog boxes are modeless. A modeless dialog box means that you can do other tasks while the dialog box is open.

Modeless dialog boxes let you have several dialog boxes open at one time. For example, if you open the Apply Properties dialog box, a modeless dialog box, you can then press the Select Surface toolbar button. You can then go back to the

Apply Properties dialog box and select the Surface Properties tab.

Now go to the Model window and click a surface to which you plan to apply surface properties. You can go back to the dialog box, select the properties to apply, then press the Apply button to apply them to the surface.

Expression Evaluator

In many dialog boxes within TracePro, you will encounter numerical data entry fields that have a yellow background color. This color indicates that the field has a built-in expression evaluator. (See “Background colors” on page 2.53.) You can enter a mathematical expression in these fields that evaluates to the number you desire. Mathematical operators that you can use include +, -, *, /, and trigonometric functions. In order for the expression evaluator to interpret the field entry as a mathematical expression, the expression must start with the equal sign

(=). The result of the expression evaluator will not be shown in the field box, but the appropriate value will be used in the model in place of the expression.

FIGURE 1.11 - Portion of a dialog box showing an example of the Expression Evaluator. The Expression Evaluator can be used in any numerical data entry field which has a yellow (default) background.

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The TracePro Graphical User Interface

For a complete list of valid input for expression see Table 1.1

.

Table 1.1: Expression Evaluator Commands

	Name	Example	Result
Operators
u	Unary Minus	=-6	-6
+	Add	=12 + 2	14
-	Subtract	=12 – 2	10
*	Multiply	=12 * 2	24
/	Divide	= 12 / 2	6
^	Power	= 12 ^ 2	144
%	Modulus	=12%6	0
		=12%5	2
Constants
PI	pi	=PI	3.14159
E	e	=E	2.71828
Functions
SIN	Sin (Radians)	=sin(PI/4)	0.707107
COS	Cosine (Radians)	=cos(PI/4)	0.707107
TAN	Tangent (Radians)	=tan(PI/4)	1.0
SIND	Sin (Degrees)	=sind(45)	0.707107
COSD	Cosine (Degrees)	=cosd(45)	0.707107
TAND	Tangent (Degrees)	=tand(45)	1.0
ASIN	ArcSin (Radians)	=asin(0.707107)	0.785398
ACOS	ArcCos (Radians)	=acos(0.707107)	0.785398
ATAN	ArcTan (Radians)	=atan(1)	0.785398
ASIND	ArcSin (Degrees)	=asind(0.707107)	45
ACOSD	ArcCos (Degrees)	=acosd(0.707107)	45
ATAND	ArcTan (Degrees)	=atand(1)	45
ABS	Absolute Value	=abs(-12)	12
LOG	Log base 10	=log(12.3)	1.08991
LN	Natural Log	=ln(12.3)	2.5096
EXP	Exponential	=exp(2.03)	7.61409
SQRT	Square Root	=sqrt(144)	12

TracePro 5.0 User’s Manual

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