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:
- If not already move the cars root approximately .5m up from the ground
- (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.