llVolumeDetect(TRUE) and llSetPos

[Kayaker Magic]

     I have an object that I want to briefly dip below the ground. If it is a physical object I can do this by setting llVolumeDetect(TRUE) and calling llMoveToTarget. But I want to avoid the overhead of a physical object. I made my object non-physical and used llSetPos to move it. But llSetPos refuses to move my root prim below the ground!

     I used to have an invisible root prim a few meters above the rest of the build so I could push the visible parts of a non-physical object below ground. I thought that llVolumeDetect(TRUE) would make this extra prim unnecessary.

     I could switch to using physics and bogging down the sim just so I can save that one prim, but I seem to recall that a physical object with a seated avatar cannot go below the ground even with llVolumeDetect(TRUE).

     Anyone know another way around these limitations?

 

[Rolig Loon]

I was trying to do this same thing last month. I managed to make a pretty nice seat that looks like it has a hydraulic lift under it, using llVolumeDetect and physics to get it to move smoothly up and down.  My goal, like yours, was actually to force the seat underground, but I couldn't find a way to do it with the av on the seat. I suspect that it can't be done.  Av's just don't like to be under sod.

[Void Singer]

won't work with an avatar seated on it, the av will always collide with the ground....

similarly, the setPos features seem to be routed through the physics collision engine and they won't allow you to get more than the root position level with the ground (seated avatar or not).... the only tried and tested way I've found was solo objects using volume detect and physical movement.

[Paul Hexem]

As far as I know, the only way to force prims underground is with non-physical prims, and to leave part of the linkset above, such as your invisible root.

[Rufus Darkfold]

I was able to ride a physical+volumedetect vehicle a ways underground a few months ago.   Maybe something changed.

At first, it wouldn't go more than about 50 meters underground.  There were no megaprims in the build, I'm sure the whole thing was underground.   I think I was using llMovetoTarget().

Then it suddently went into a dive into the blueness,  I bailed out at -12000m or so and it popped me up to the surface.

The boat was lost.

 

 

[Void Singer]

I should mention that I know one way to fake it....

if the root is offset upwards, and the av sits on that but is animated to be lower, you will appear to be underground, although for all physical intents and purposes you will be above.

 

once upon a time when the ground didn't stop physical prims, and we could make phantom avatars you could sail around as you pleased underground.... but that's been LONG gone (but if someone find a hack for it, I'm game... but I haven't seen it since)

[Rufus Darkfold]

An avatar can be put underground with llSitTarget or  PRIM_POSITION in llSetLinkPrimitiveParams.

The object sat on remains above-ground.

The avatar pops back up to ground-level when he/she stands up,  but it is possible to move around underground using PRIM_POSITION while seated.    Suitable use of animations can make it look a bit more natural  (though you still have the usual jerkiness associated with non-physical movement).   No need for special animations, the stock ones will do.   The sit target or PRIM_POSITION does the actual movement.

There is probably some limit on the distance from the root,  but it seems to be more lenient than the usual linking rules.

I have just verified this.

 

[Void Singer]

I *think* PRIM_POSITION might be bound by the link rules, but perhaps not (haven't played with large manual offsets in a while), but I can confirm that sit targets themselves are only limited to 300m on each axis, and don't care about... anything

 

.... and I should have remembered this since I once made a product or two that would seat you offworld

(it was right after sitting on off region mountains was publicized... someone made a joke about having a picnic out there.....  so I built a picnic table with seating for 6 about 20m off the region into the void)

[Rufus Darkfold]

The limit for PRIM_POSITION seems to be 1000 meters total distance from the root,  with a limit of 75 meters of movement per PRIM_POSITION call.

 

[Void Singer]

holy shi.............. I need to rebuild that picnic table into a cabin in the mountains.... the next valley over! LOL

[Rufus Darkfold]

If the root is physical, PRIM_POSITION on the avatar still works, and I can still get underground, but then there is a force pushing me back towards the surface,  as well as tending to tip over the whole linkset.