#SL Vehicle Problems

This roll out of the Pathfinding code has caused a number of people problems. The wackadoodles are ranting in the forum. Those helping fix the problem are adding to the JIRA’s and creating new JIRA items. The forum thread is an exercise in ignorant arrogance by entitlement types… they are basically demanding: it’s a problem, you fix it. The Lindens have been looking for problem vehicles for weeks now. They need specific examples to learn what is wrong. Once they know they can create a fix, workaround, or explain what the problem is.

If one cannot provide specific steps for reproducing the problem, the Lindens can’t fix it. The vehicles they are using and testing work. So, if one is not going to provide specifics then please specify which hand you want them to wave in the air.

The thread is a good example for why Lindens tend to avoid conversing with residents.

Whatever, we know that trying to move mesh items from PF regions to non-PF regions is going to be a problem. That simply cannot (well… won’t is more accurate) be fixed. The problem will resolve itself when PF rolls to the entire grid. So, the Lindens are spending their limited time on other matters.

There is also a problem with how Havok, the physics engine that upgrades with PF, handles vehicles. Havok changed. Now, poorly made vehicles misbehave. Also, some workaround methods used by crafty vehicle makers for SL problems in previous Havok versions create problems now.


The way we see and work with terrain is not changing. But, how Havok sees terrain and works with it is changing and that has affected vehicles. For one thing, while we see the terrain change as we work with it, the terrain physics will not change until later.

Havok used to look at terrain as a grey scale height map. Now Havok sees it as a mesh, lots of triangles.  How Havok sees vehicles colliding with all the triangles is where the problems are.

Havok can handle things. But, how we make our vehicles makes it easier or more difficult for Havok. Problem vehicles that have been submitted to the Lindens for examination have shown problem vehicles are either poorly or uniquely constructed.

Using mesh anything for the collision surface is a problem. Such vehicles are likely to hang, get stuck in terrain. Vehicles that use high gravity to stick to the road are also likely to get stuck.

I’m not a vehicle creator, so I’m not up on what the problem and fixes are. But, I do know the Lindens are not going to fix SL for vehicles that do not use best practices for Second Life vehicle construction (wiki updated January 2012 – check the Discussion page). The Lindens are also NOT going to roll back Pathfinding. It will be delivered and rolled out, eventually. So, some vehicles are going to have to be redesigned to use best practices.

See: Second Life Good Building Practices – This the new page for Best Practices and it is frequently updated.

From the Deploys thread a fix for some vehicles is described as:

To fix cars hanging at low speed use the following steps:

  1. If not already move the cars root approximately .5m up from the ground
  2. (for high prim no attachment cars) Set the root to prim for physics type, set the wheels to convex hull (a mesh wheel using a spherical physics shape is preferred) and set everything else to none.


If you want to test your vehicles, get to Magnum and test your vehicles. If there is a problem consider the vehicle best practices in the wiki. If you still feel it is a problem write out how to reproduce the problems you see and get the info into a JIRA item. If there is a problem in PF, it will get fixed. If there is a problem with the vehicle construction, you hear something.

The problem the Lindens are having is all the current problems are on the vehicle side and the problem vehicles are not built to best practices. If yours is and it isn’t working right, get it to the Lindens.

6 thoughts on “#SL Vehicle Problems

  1. Thanks for keeping all of us updated, but I’m not all that inclined to defend LL and their practices. I would only expect people to be upset when things get broken, especially if they have lots of customers and LL breaks something or they are a customer that spent good money on something only to have LL break it. To not expect backlash when something gets broken seems much more crazy, than those ranting about broken things. Maybe it is the nature of the beast.

    As a merchant tho, the last thing I’m going to do is be mad at my customers if I put out something that breaks other things. And, I’ve been in business long enough not to let their anger get me down, knowing that when I fix it, they’ll be equally pleased.

    All that said, you can’t believe how excited I am to see hand animations(morphs) actually being worked on. Hey, and it only took 5 years. I’m not holding my breath tho, nor am I anymore hopeful that the 5 year old animation looping bug will EVER be fixed.

  2. Please be careful with your broad brush of labeling people “wackadoodle” less that label soon be applied to you as well. Some people posting in the forums HAVE legitimate questions/concerns not yet worthy of a jira entry.

    • Some people do have legitimate concerns. Whether they are a wackadoole or not is determined by how they voice that concern not the legitimacy of the concern.

      • The JIRA system wouldn’t be my choice for getting useful info from users.

        The AR system isn’t so good a model, but look at how it makes it easier to provide relevant info. Doing that at JIRA level is a hard problem. On this particular issue, we need to provide unambiguous information about the regions and the vehicles involved, and some of that isn’t obvious.

  3. I really feel for those Lindens involved in this step of the rollout.

    Deciding not to spend time supporting backward compatibility during transition is no doubt the right choice, but man do a few people act as if you’ve personally peed on their cookie jar. That those same people are rarely very smart or well-spoken only adds fog-of-war to the entire process.

    Adding to that the problem with poorly made content, uggh. Continuing to support poor development behavior, even if proper feedback wasn’t given before, is rarely the right choice; each time the right choice is made and communicated plainly it gets a little easier the next time. Of course, the beatings can deter anyone from making and then communicating the ‘right’ choice.

    Good luck to everyone involved, hope the migration is relatively quick.

    • Good points.

      I see many of those ranting, being the most disagreeable, and going into ad hominem attacks on Lindens as also being the least informed, tolerant, and knowledgeable. Amazingly those people don’t notice they are often the only one (or just 2 or 3) with the problem. Quit often they seem to lack the ability to empathize with those that will need to fix a problem and provide them the information needed for a fix. And they post week after week. Absolutely clueless…

      The Lindens have started adding to the Good Building Practices. It is great that it is on an open section of the wiki so that users can add information too. So, it is possible for users to make better content and understand some of the changes in SL.

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