Linden Script Tutorial

This morning I have corrected the count = 0 variable setting on poster 20.

When I have the time I will update the tutorial exhibition booklet as well.

Object-Name: Feedback Poster
Region: Daydream SE Islands (232960, 246272)
Local-Position: (223, 18, 24)

Hi Clive -- Going through your Scripting Tutorial, and it's great!

However, I found a bug: Poster 20 has a 'count == 0' that's claiming to initialize count to zero, but it's a comparison (double-equals) rather than an assign (single equals). Guess how I know this is a bug... believe me, I've done it more than once :-).

Cheers,
--yachris s.

Object-Name: Feedback Poster
Region: Daydream SE Islands (232960, 246272)
Local-Position: (223, 18, 24)

cheers Mr Pro,

very good walk-thru to scripting.

heres a few maybes :

types
in step 23 , a rotation vector is converted from a 'quartinion' into radians, then into degrees.
it might be worth a comment to say what a quartinion is
(I have no idea - I'l look up llGetRot() in a bit...)

program flow
I had to make a few guesses about which functions ( like llDialog ) cause the flow of execution to 'halt' at that line until the dialog is dismissed.
other functions (like timers) drop straight thru, and are handled by other event handlers

I understand if you'd rather leave this out of the tutorial
Im not sure which poster I would use to open this 'can of worms'!

naming conventions -
on poster 36, a global integer is defined as CHANNEL (all caps)
any reason for this ? if so , best mention it

thx
Elaine


Note from Clive:

I have deliberately missed out the word quaternion as I felt it was too complicated a concept for a beginner. Some of the variable names on poster/script 36 are in capital letters purely for the sake of readability.

If you bought the original poster book and would like a free copy of version 1.1 please IM me.

Version 1.1 contains the following changes:

1) Poster 25 typo corrected
2) Poster 31 (and associated code) updated to reflect the fact that Linden Labs are deprecating a number of the llMake functions including the llMakeExplosion function, in the next release of the viewer (tomorrow?)

I have also updated the version of the book available from slboutique and slexchange to 1.1

I have noticed that with the IE7 browser slurl links may not work. If you already have the Second Life client installed it is also possible to find the tutorial by cutting and pasting the following URL into your browser bar secondlife://Daydream%20SE%20Islands/206/40 or in-world by choosing Search > All and searching for the phrase learn linden

Early in March 2007 Linden Labs deprecated a number of llMake functions including llMakeExplosion, llMakeFire, llMakeFountain, and llMakeSmoke and these functions will not be supported in the next viewer. (Thanks to Deadcrow Sands for pointing this out)

Accordingly I have updated poster 31 in the exhibition to use the llParticleSystem function instead.

I will update the LSL exhibition book with the changes to posters 25 and 31 as soon as I have time.

Igor Bertolucci kindly pointed out a typo I'd missed on poster 25 where it said llGetPos rather than llGetRot. I have corrected this on the poster in the exhibition and will correct in as soon as I have time in the LSL exhibition book. If anyone has bought the book containing the typo please IM me for a free corrected copy which I'll send as soon as it is available.

I am planning to write two new book in-world as time permits. (There's always so much to do in FL!)

The books will be:

1) Using structured design techniques for creating Linden Scripts. This will give a brief introduction to the software lifecycle and then look at the adaptation of pseudo-code to LSL design. This is important as so often coders jump straight in without considering the overall design of the script. Taking time to design the script properly can save hours debugging later.

2) Staged exercises helping you to learn LSL. To help beginners learn LSL by doing, this will look at the modular development of a couple of scripts. I am planning to develop two scripts in this way:
i) a colour changing, flashing light
ii) a flying carpet (very useful in sandboxes)

I am starting to get concerned that several LSL commands I have tried lately don't always work consistently or reliably!

1) In the first instance I was trying to get the agent's camera to automatically position itself in front of the movement chairs used in the exhibition when the user sits down (the default is behind).

I have used the following code in state entry but it only seems to work after a script reset, not all the time:

llSetCameraEyeOffset(<-2, 0, 1>); // the camera is 2m behind and 1m above the object
llSetCameraAtOffset(<2, 0, 1>); // and looks at a point that is 2m in front and 1m above the object

2) Also Brad Fulman asked me to look at a script of his. I have experimented with the llSensorRepeat function and can only conclude it doesn't work properly !!!

I can get it to detect an AVATAR at a miminum range of 1 metre.
I can get it to detect an ACTIVE object at a minimum range of 1 metre.
The problem appears to be when the types are OR'd together e.g. AGENT | ACTIVE | PASSIVE | SCRIPTED in which case it won't detect properly.

I have recently created a LSL Tutorial Group to accompany the exhibition in-world and it already has over 75 members :-)

The aims of of the Linden Script Tutorial Group are to:

1. Keep members up to date with changes to the Linden Script Tutorial Exhibition

2. Let members know when new in-world books associated with the exhibition are published.

3. Let members know about new in-world LSL resources.

4. Let members help each other with scripting problems.

Object-Name: Feedback Poster
Region: Daydream SE Islands (232960, 246272)
Local-Position: (223, 18, 24)

hello, your presentation is good, but for others language like french, it's hard to translate, tnaks

D1R1 Benelli