Flexible
Since
SL 1.9.1, a
prim can be made
flexible. Flexible prims ("flex prims") are a
client-side effect and are automatically made
phantom and
non-physical. However, flex prims can be
linked to a solid,
physical root prim and will, thus, take on those properties as well (though it's buggy).
Constants
llSetPrimitiveParams PRIM_FLEXIBLE parameter to toggle a prim's flexibility on/off, softness (rigidity),
gravity,
friction/drag,
wind, tension, and
force:
Notes:
- Flexibility ignores prim shear but the force PRIM_PARAMETER parameter can simulate shearing to a degree.
- Flexible objects add virtually zero burden on the simulator, which sees them as identical to any other primitive; on the viewer, they are very tightly time-sliced so as to scale with the capabilities of the machine and never bring down framerate in a significant way. (Yedwab Linden, 4/14/06)
- Flexible objects already have an LOD system built into them, so things which are further away update a lot less frequently, and are given much less priority than nearer flexible objects.
If you enable the Debug Console in the Debug menu, it currently spams the various bins ("0: " being the farthest bin and "9: " being the nearest avatar attachments) and the number of flexible objects rebuilt per frame, how many total in the bin, and the time per frame in seconds spent on that bin. So you can try to figure out what the algorithm *actually* does, as opposed to what you think it does. (Yedwab Linden, 4/15/06)
- In order to attach objects to the end of a flexible object, we need complete hierarchy. This is a separate feature which we're not currently working on, but should happen sometime in the future and which will enable attaching things to the end of flexible objects automatically.
Flexible objects are currently not elastic (that is, they maintain their initial length). To make both ends fixed creates a problem either with excessive elasticity or instability, and these are issues which were not in the scope of "Flexible Objects 1.0". (hint, hint) (Yedwab Linden, 4/15/06)
- Linking things the to the end of flexible objects requires the notion of a link hierarchy with true parents and children. This will come later, but the extension to flexible objects will be automatic. (Yedwab Linden, 4/17/06)
Prim