Joining the Developer Group

1. Joining the Developer Group • Register an account and select an avatar name at www.secondlife.com • Email your avatar name to cwt@uark.edu (or as otherwise directed) • Look for the invitation dialog box and click Join

2. Connecting to the Island • Open the Map tab • Type University of Arkansas into the Search box and click the Search button. • Click University of Arkansas in the results • Click Teleport

3. Introduction to Second Life Scripting

4. Resources • http://lslwiki.net/lslwiki/wakka.php • http://wiki.secondlife.com/wiki/LSL_Portal • http://vw.ddns.uark.edu/mediawiki • Resident Experts: Casey Bailey – Dillon Potez Keith Perkins – Thinker51 Brandenburg Nicholas Farrer – Anon Frog

5. How to Create a Script (In Object) • Right Click object and select Edit • Click on the Content tab • Click “New Script”

7. LSL Basics • Java-like syntax, but not object oriented • Strongly typed • Event and state driven • Next event will not be processed until current event finishes. • Includes logic and looping constructs such as for, if, while, and do-while

8. Primary Built-In Data Types • Float – Same as the float type in C • Integer - 32-bit signed integer • String • Key • Vector • Rotation • List

9. Key • Unique identifier for just about any object in Second Life (UUID/GUID) • Contains hexadecimal characters separated by dashes • Example: • a822ff2b-ff02-461d-b45d-dcd10a2de0c2

10. Vector • Simple data structure of 3 floats, written as <x, y, z>. • Used to hold position, velocity, and color. • Individual elements can be accessed by using the .x, .y, and .z after the variable name. • For color: • X = Red • Y = Green • Z = Blue • Examples: • vector example = <0, 0, 1.0> • example.z gives the value of 1.0

11. Rotation • Simple data structure of 4 floats, written as <x, y, z, s>. • Used to hold rotation information as a quaternion – See http://en.wikipedia.org/wiki/Quaternion • Individual elements can be accessed by using the .x, .y, .z, and .s after the variable name • Examples: • rotation example = <0, 0, 0, 1.0> • example.s gives the value of 1.0

12. List • Generic Container that can hold any number of elements of any type. • Grows dynamically up to maximum amount of memory • All element access is done through llList2<type> functions which take the list and position (0-based as parameters) • Examples: • list example = [7, “Blue”, [0, 1, 2], <5,5,3>]; • llList2Integer(example, 0) returns 7.

13. States • Every script must have a default state. • All objects begin in the default state. • Additional states can be declared using the state keyword. • Event functions are for that specific state. No direct way to have a event handler that works in all states.

14. Variable Scope • Global variables are declared outside of all states • Local variables are declared inside of functions • There are no state variables (variables declared within a state but outside of all functions)

15. Hello World default { state_entry() { llSay(0, "Hello world!"); } }

16. Basic Chat Output Functions • All have two parameters – Output Channel (Integer) and Message (String) • Different functions have different ranges: • llWhisper – 10 meters • llSay – 20 meters • llShout – 100 meters • llRegionSay – Entire island (but not on received on clients) • Chat Channel 0 is the channel that is displayed in the Second Life client.

17. Default Script default { state_entry() { llSay(0, "Hello, Avatar!"); } touch_start(integer total_number) { llSay(0, "Touched."); } }

18. Events • Most events can be triggered multiple times per simulation clock cycle. • For the touch_start event, the total_number represents the total avatars that have started touching the object. • Information for each avatar or object detected can be obtained through the llDetected functions.

19. default { state_entry() { llSay(0, "Hello, Avatar!"); } touch_start(integer total_number) { integer i = 0; for(; i < total_number; ++i) { llSay(0, "Touched by “ + llDetectedName(i)); } } }

20. State events • State_entry – Triggered when state first becomes active • State_exit – Triggered when state changes and becomes inactive

21. default { state_entry() { llSay(0, “Default State.”); } touch_start(integer num) { state active; } state_exit() { llSay(0, “Leaving default state.”); } } state active { state_entry() { llSay(0, “Activated”); } touch_start(integer num) { llSay(0, “Touched.”); } }

22. Lab • Verify that you can teleport to the Second Life island • Get added to the development group • Build an object, add a script, test it out