I have been posting less than usual of recent, principally I suspect as result of a good dose of seasonal flu. I am starting so feel much better now however and standing on one of my islands just the other day, I began to recall the comment that I had once read in a blog or posting someplace about there not being much actual life in Second Life. Sure there are plenty of buildings and avatars, waving flags and swaying trees, but actual life, not so much. In the light of this comment I started to have a good look around and thought the criticism not so un-justified, where indeed is the life? at which point I began purchasing some roaming creatures from different places for my sim, it does produce a different feel and perception without doubt. Now that I am working more and more in OpenSim, I have once again started to sense the need for some background life features, but these are not so readily acquired at the moment in OS as they are in SL. Back in my early days of SL I had made a simple flying Parrot, so decided to start with that, except this time the parrot would become a seagull. The animation is simply a llTargetOmega() function placed in a central transparent hub that connects to the bird through an equally transparent rod, the whole thing just rotates. To make it a litle more interesting, I used some loops with random iterations within the main hub to drive it in x,y and z axis using llSetPos(). As a final touch I included a random script to play suitable bird sounds, and altogether not bad. Anyway I dropped my new creation in place, made a half dozen copies around the region set everything in motion, once again not bad, or so I thought.
Next, I decided to go for something a little different, something that I had not tried before, a walking bird, a stork. I put the prims together and after a suitable amount of stretching and trashing, I had something that looked OK, well from a short distance anyway. To begin, I decide that all I need was a preset rectangular path for testing and then use llSetPos() to get the thing going. I also rummaged and hacked around to produce a function to have the prim always face forward, for obvious reasons. Next I attached two thin poles for the legs, with profile cut to the center axis and made use of a variation to a door script to make them run from messages sent out from the main body, not the most elegant of solutions and one prone to lag dysfunction over long periods, but this was only a testing stage anyway and I can soon put a rotation reset function in later to keep things tidy. Ready to go, I touch the body and after a few surprising and physically impossible contortions for the poor stork, I finally make a few script changes and it runs, brilliant, or so I thought. Back it comes to the start point, I click again and touch_start sets it off once more around its small 12 by 12 metre circuit, marvellous, or so I thought. Then the moment comes, that would lead to the best part of a wasted afternoon. I decide to put the whole sequence into a loop, and get ready to sit back watching my new creation walking around with the occasional small departures from what could be otherwise described as synchronised marching to the sound of stork calls. Indeed everything went very well until just before completion of the third circuit, the bird stopped ! Not moving standing motionless, one leg pointing straight down, the other pointing out at an unexpectedly high angle reminiscent of a Nazi salute, curses. Whenever these things happen in programming, I find despite experience, I am always overcome by the optimism of the two minute fix phase, where I find things that while not strictly correct, actually have no baring on the problem whatsoever, and after numerous mods and tests, the problem all to often remains. At such times, trust me, always go for the manual, but no, no, hack on regardless, changing and testing changing and testing. I’m not sure now if was someone turning the lights on for me as I was by this point sitting in the dark, anyway, eventually I turn to Google and before long discover that there is a bug report in for llSetPos(). Apparently llSetPos() bombs out of loops at somewhere between 100 and 200 iterations, magic. But hey-ho we are made of sterner stuff, so what’s the fix, well obviously make sure that the number of calls to llSetPos() is well within limits. I setup a simple prim in a loop that moves and reports to me, and after 50 tests I had bomb outs at 146 as the lowest and 188 as the highest, worth baring in mind. This gave me some optimism as my stork only consumed 128, but such small test samples are just misleading and sure enough it failed, at 104, but 96 seems to be OK at the moment, but do read on.
So what do you do, set it running for the two small circuits and place a sign around its neck saying please touch me to witness a short walk, no not really. I just need to find a way to reset the script, and llScriptReset was not it, instead I devised this fiendish little approach, which seems to runs OK
default{
state_entry() {
}
link_message(integer sender_number, integer number, string message, key id){
if(message=="start") {
state back;
}
}
}
state back{
state_entry(){
//call movement function
state forward;
}
}
state forward{
state_entry(){
//call movement function
state back;
}
}
At the moment I am still testing the solution, though I must say that since starting to publish this blog posting I have just looked in on old storky and it has actually failed at 96, so onward and downward in the search for a stable number. Of course I could be missing the whole point somewhere here, so if you have experienced any problems with llSetPos() in OpenSim and found a work-around then please feel free to post you comments. Otherwise I at least hope that my experience will be of some help to you.
Kind regards Vega
If you are looking for some free 
Following my recent post on installing OpenSim on a USB drive, which I have been continuing to use around the college with real success on both 32 or 64 bit platforms. The other day I came across a posting on http://iliveisl.com/the-need-for-speed-usb-opensim/ by Ener Hax where a number of drives are assessed for performance including frame rates. If you are thinking about this approach, then I can recommend paying a visit and having a read. Comments welcome.
Recently I posted a blog about my installation of openSim on a standalone machine, well I was reading through some new OpenSim postings yesterday when I came across an article entitled “OpenSim on a USB”. The article described the installation of Mowers, OpenSim and Imprudence, all running from the USB drive. I confess that for some reason I seem to have run into a few difficulties with Mowers with regard to getting Apache to stay running. After trying a few of the more obvious tweeks like paths in the conf files and ensuring that port 80 was not already being used by another app, I thought why not use Xampp, which was already on my PC and simply needed to be installed across onto the USB. After that I downloaded the OpenSim binary, unzipped and went through the basic setup including a new avatar; by the way I named my new region port-able, which I thought appropriate. Finally I installed Imprudence. With all that done, and it does take a fare bit longer for a USB. I started Xampp with Apache and Mysql services; you will need this if you wish to use the Mysql rather the standard SqlLite. With Xampp running I started OpenSim. The next part was to run Imprudence, and entered in the user details for my avatar for localhost. After a short delay, there I am standing on a small island, brilliant.
Starting back in the days of 3DML and Flatland Rover, you may remember that yourself, I guess I have been working in and making use of Virtual Worlds now for ten years. Being able to stay in touch with developments that surround the general theme of education and training is an aspect of my virtual and real world activity that I always find interesting and often surprising, particularly true I find these days of improving functionality between the virtual world and web. So I was pleased to stumble across the Virtual Worlds Education Roundtable site the other day. The name probably tells you all that you need to know about the purpose of the site and I can recommend a visit.
Its usual at around the summer break for me to set myself a project of some kind. This year there have in fact been a couple of little projects but for this post its about my decision to get a vehicle to work reliably enough in OpenSim that is stable enough on the one hand and use-ably fun on the other. It was during the students projects of the summer term that I first really became aware of the issues here, as one group tried it seems very much in vain to get vehicles running around without aircraft zooming of to some distant a horizon, cars flipping over onto a front bumper or boats turning turtle and plunging to the depths of the virtual ocean . Initially my approach had been to supply them with some basic SL scripts and get them to try them out, make a few changes and see which worked the best, but clearly it was not going to be as simple as that.
