Tuesday, 6 February 2007

Comments by Desmond Shang

Here are some posts by Desmond Shang in the BB. They describe the open source Caledon National Rail.

I've been whopping busy but my latest major push is getting the 19th century Caledon National Rail fully operational.Tracks are in 11 sims, split into the Victoria, Caledon On Sea, Cay, and Mayfair lines. With perhaps some special surprises to come.

The code, textures, sounds, shape and everything else about the trains is open-source, in hopes that I'll get improvements from other folk over time.

Once it's fully operational (hopefully a few weeks from now, maybe less?) I can outline what it takes to design a train for our rails, and I'm willing to have other people run trains if they like. It's a tad complicated, with prim limits, size, track curves and a few other things making for nasty requirements, but it's quite possible. I'll have to cook up a document because once I do, the trains that others make and contribute will be far better than my own.The 'big one' is that anything that runs on Caledon's rails must be 100% full mod and open source, and free to anyone who asks for it. Caledon's own current train and rail code is available as a freebie in Central Park, Victoria City.

Caledon National Rail has 'real' rails, solid and stick up from the ground, but not made physical or anything. The gravel bed / ties are a prim.The trains themselves aren't fixed to the rail, but rather are scripted nonphysical objects that move along in a manner that they mathematically mesh with the rails positionally. I use a combination of global grid coordinates, simple messaging and simple timing - the trains don't 'pull' the cars, the cars simply know when to start and stop on their own based upon either say, a 'ten second' stop or a quickie message from the locomotive that it's time to pull away from the station now. Easy easy stuff.

Maybe easy for Desmond. I am going to get a copy of the train script and, after I figure it out, I will put parts of it on the Script Modding section of my website. Meanwhile, I hope Desmond will keep us up to date on those special surprises.

No comments: