Attaching objects to vehicles

[Frank90a]

Please don't kill me if this is some sort of taboo subject. I noticed the there isn't even a hint of how this works anywhere here or online. But I just wanted to test how the virtual world works. More than once I accidentally attached objects to a boat. No big deal. Just delete the boat rez another one. But I noticed people have actually change things on there boats, so I tested it. I made boxes, spheres, toruses. Attached to different places. Attached to different vehicles. Took vehicles apart and put them back together. All the same result. Scripts don't work, and parts fly off. But why? Don't get distracted here. I'm not desperately trying to attach some random thing to a boat, especially if it is as taboo as everyone including the World Wide Web makes it sound. I just don't like the answers "It's magic" or "That's bad". Do any of you computer gurus out there know why that breaks a vehicle?

[Lindal Kidd]

Aren't vehicles limited to 31 prims or something like that? We used to get around that by having two objects...one a very simple vehicle, that you sat on, and the other a much more complex vehicle-shaped object that you wore.

[Rolig Loon]

As long as you have mod perms on an object, you may link anything you like to it (including yourself, since that's what you are doing when you sit on an object). There are a few limitations like prim limits, of course, but they won't usually keep you from linking a prim here or there.  The scripts in an object will make a lot of difference, though. Especially in something like a vehicle, scripts have to keep track of which links are supposed to do what.  It's not a good idea to have seats rotating like wheels, after all.  A well-written script usually identifies the important links on rez (usually by restarting the script itself) and then generally doesn't need to check again except in the special case of an avatar sitting or unsitting.  If you link a random prim to the object, though, the script can no longer trust what it used to know about its links.  It may start moving things that are not meant to move, or worse.  There are ways to help a script know what to do with a new link -- just restarting the script may sometimes be enough -- but most vehicle scripts are no-mod, so you can't mess with them.

[animats]

It's definitely not taboo. If you have modify permissions on a vehicle, you can modify it. Lots of people do this.

Some scripts identify the important parts by name. Those are tolerant of added accessories. But if you add something, you may have to do a "Reset Scripts" to get the scripts to go find all the working parts again.

If you want motorcycle parts, there's Karyn's Chopper Parts. Look for the big box of free parts to the right of the front door. Also, there's a junkyard to the right of the main building. Just like real life, there's an aftermarket parts business in SL.

All this stuff is user-created, so it may not work well together. So save a copy of good vehicles before modding.

[Frank90a]

Thanks for that. That actually put me miles ahead of where I was. Yep. I can add objects to a "test vehicle", take the vehicle, and drop it back inworld without it falling apart or script errors. That also prompted me to look into limitations. I appreciate you both for the help.

[Frank90a]

32 prims, actually. I just discovered that myself. In that case it actually tells you what you did wrong. It turned out that a simple mesh object I made in Blender took up less "cost", as it gripped about, and was more likely to work. Still you must watch where you attach your coffee cup, ice chest, and fishing pole when playing on your boat, but indeed it does work.

[RoxyCyn]

Well-made mesh parts can often help reduce your overall land impact on a moving object (vehicle).  In the past, the 32 prim limit applied and scripts would just 'shut-down' and no longer function to move the vehicle.  That's somewhat a thing of the past now, however some scripts will still throw that error message back at you.  Karyn's even has a script for vehicles over 32 prims.  get that and drop it into the root prim and you're good to go.  Good luck and have fun.  

Edited March 8, 2021 by RoxyCyn
punctuation