Hello Avatar

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Revision as of 20:32, 2 October 2007 by Ppaatt Lynagh (talk | contribs) (and also explain how llRemoveInventory(llGetScriptName()) helps newbies learn by dragging scripts to run them)
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The New Script

The script you get from the SL GUI, when first you ask to create a New Script in an object or in your inventory, was this script, as of 2007-08:

default
{
    state_entry()
    {
        llSay(0, "Hello, Avatar!");
    }

    touch_start(integer total_number)
    {
        llSay(0, "Touched.");
    }
}

That script shows you how to get something to happen when you save or reset the script.

The example thing that happens is { llSay(0, "Hello, Avatar!"); }. The other example thing happens when you touch the object.

How To Try New Lines of Code

To create your first copy of this script, you're supposed to find the New Script button in the Content tab (beside the General, Object, Features, and Texture tabs). Then you're supposed to notice that you can edit this script and click the Save button repeatedly to try out new code.

For example, you might try:

default
{
    state_entry()
    {
        llSetText("look at me blue", <0.0, 0.0, 1.0>, 1.0);
        llOwnerSay("OK");
    }
}

Each time you edit and Save, the SL GUI will compile and run your new line of code. Every time you click Reset, the SL GUI will run your one line of code again.

Your First New Lines of Code

Exploring new commands in this way can run you thru a long series of demoes that teach you about how scripts work, such as the following.

  • Twiddle the red, green, and blue intensity, also the "alpha" opacity/ transparency:
        llSetColor(<0.3, 0.3, 0.3>, ALL_SIDES); // darken
        llSetColor(<1.0, 1.0, 1.0>, ALL_SIDES); // lighten
        llSetAlpha(0.7, ALL_SIDES); // make translucent
  • Twiddle the label of the object running the script:
        llSetText("look at me green", <0.0, 1.0, 0.0>, 1.0); // label
        llSetText("look at me black", <0.0, 0.0, 0.0>, 1.0); // label differently
        llSetText("", <0.0, 0.0, 0.0>, 1.0); // do not label
  • Move and rotate while not physical, then kick and spin while physical and bouncy.
        llSetStatus(STATUS_PHYSICS, FALSE); llSleep(0.1);
        llSetPos(llGetPos() + <0.0, 0.0, 2.1>); // teleport up the Z axis
        llSetPos(llGetPos() + <0.0, 0.0, -2.1>); // teleport back down the Z axis
        llSetLocalRot(llRotBetween(<1, 0, 0>, llGetSunDirection())); // turn the East face to the Sun
        llSetLocalRot(llEuler2Rot(ZERO_VECTOR)); // turn the East face to the East
        llSetStatus(STATUS_PHYSICS, TRUE); llSleep(0.1);
        llSetBuoyancy(0.9); // bounce well, without floating
        llApplyImpulse(<0.0, 0.0, 1.0>, TRUE); // advance along the Z axis
        llApplyRotationalImpulse(<0.0, 0.0, 3.0>, TRUE); // yaw about the Z axis
        llSetStatus(STATUS_PHYSICS, FALSE); llSetStatus(STATUS_PHYSICS, TRUE); // zero rot inertia
  • Poke around inside the object running the script:
        llOwnerSay( (string) llGetAgentSize(llGetLinkKey(llGetNumberOfPrims())) ); // often not ZERO_VECTOR while avatar sits
        llOwnerSay( (string) llKey2Name(llGetLinkKey(llGetNumberOfPrims())) ); // often the name of the sitting avatar
        llOwnerSay(llList2CSV( [ZERO_VECTOR, FALSE, TRUE, STATUS_PHYSICS, PI] )); // some named code values
  • Chat a question for you the object's owner to answer:
        llDialog(llGetOwner(), "A clarifying demo?", ["No", "Yes"], 7); // chat some Q & A
        llDialog(llGetOwner(), "Choose an arc:", ["PI_BY_TWO", "PI", "TWO_PI"], 7); // chat some Q & A

These llDialog examples start you into a new lesson that could be your next lesson: the work of learning how scripts and avatars communicate with one another. In particular, you could also learn to make sense of such examples as:

        llRequestAgentData(llGetOwner(), DATA_BORN); // the data-of-birth of the owning avatar

The parameter 7 shown in the llDialog examples chooses a chat channel on to which the llDialog call will copy the answer you give to the question, as if you had chatted it yourself. You can see this happen if you learn to code a receiver for listen events. Similarly, if you learn to code a receiver for dataserver events, then you can llOwnerSay the results of the llRequestAgentData example.

Likely you want to make time to learn how to have one script call another before you run out of space in the one script you know how to write. To ask how much memory exists (in the task of the script of the object) that you never have yet filled with allocations of byte code, stack, or heap, try running code like:

        llOwnerSay( (string) llGetFreeMemory() );

Drag To Run Memorable Snippets of Code

Instead of always editing scripts inside an object that you might lose, you may prefer to choose New Script and edit and Save in the Inventory > Scripts folder and drag the script on to an object to run a new copy when you please. If you're dragging to run the script, you'll see the object ends up holding confusingly many copies. So you'll quickly want to learn how to tell a script to delete itself after being dragged in place to run, thus:

llRemoveInventory(llGetScriptName());

Enjoy!