Platform under waterline behaves as partial phantom.

[FaintOutline]

I have all water-land in two different sims.     I like to build a platform and set it just below the water line so that I can walk everywhere in shallow water.     On one sim I can transport to the area and walk normally --  but on the other sim I cannot, I fall through the platform to the ocean bottom when I transport, but not when I walk.   This happens in any TP, from outside the sim or within the platform.   On the sim where I fall through I have to have a prim or land above water to land on, and then I can walk on the submerged platform normally.   This happened on another sim which I no longer have, but the became normal one day.    I have changed every setting I can and still I fall through.    Also I cannot select the platform for "edit" without going below the water line.   On the one that is working I can.   So this must be a sim setting that is causing this, which I cannot change.   Currently my only solutions are an invisible platform above the water line, which is not great since I appear to be on the surface of the water, or linking to a prim that is always above the water line which does actually solve the problem, but does not explain it to me.

Can anyone shed some light on this? 

Edited July 22, 2018 by FaintOutline
added my solutions...

[Cedric Brown]

Interesting. Never experienced this issue. Is the parcel that has the issue on a sim border?

 

[FaintOutline]

Oddly all three that I mentioned above were on sim borders.   But one which works is over 4k in size.   The one that fails 2k.

Edited July 23, 2018 by FaintOutline
add info

[FaintOutline]

Cedric you are correct it does seem to be the sim edge.   If I put the above water linked prim very near the edge the platform again fails.   Putting it back in the middle and all is well.   

[encidious Opus]

I have noticed you can stretch a prim across sim borders, i.e. a boat dock, but at least if the adjoining sim is a Linden protected region, the system makes the prim phantom and your avatar will fall thru it. Havent had the opportunity to own 2 adjoining parcels located in different regions to see if it still changes the prim physics.

[Fionalein]

I'm to lazy to look up the answer but look for some past threads on constructing across sim borders...

Edited July 23, 2018 by Fionalein

[Klytyna]

I used to see this "fall through the floor when you tp in over it" problem a lot, about 6 years ago, at a social hangout with a fixed tp landing point 3 m above a glass floor over a pit with shrubbery in it, we'd see 15-20 people an evening plummet through the floor, mostly first time visiting noobs who hadn't learned to fly before coming there, and then land, like the regulars did.

First questions you ask are...

1. How THIN is the platform, too thin and the physics which is fine for walking on, will fail to stop a falling body (some sort of velocity interpolation issue)

2. How HIGH above the platform is the actual tp in point, too high and you fall through the floor.
 

[Callum Meriman]

There is a similar effect if you place a prim at 128,128 (even one that extends right down to the ground) and use the map to enter the region. You rez inside the prim.

To the OP, I would build a temporary platform just a bit above the water, then re-LM it, and remove the above-water platform. Your LM will then be above the prim and you will drop down onto it.

[animats]

Building across a sim boundary is easy, but takes some work.

Each side of a region boundary must have a prim which extends about 2-4 meters into the next sim to maintain support as you cross. Avatars are in only one sim at a time. When you go off the edge of a sim, first you're outside the sim, and you'll see a position in the menu bar outside the 0..256 range. You get support only from the region you're in, not the one you're entering. So if your prims end at sim edge, you fall when you go off the edge. The seamless world is an illusion created by the viewer.

Take a look at places where Linden roads cross sim boundaries, with Advanced->Highlighting and Visibility->Highlight Transparent turned on. You'll see the invisible patches added to prevent sinking into the ground.

[Abnor Mole]

When building supportive objects on both sides of a region boundary, make sure that the physical box of both objects is on the same level. If you don't, when you cross from one direction your avatar will be standing *in* the support object instead of on top of it, and you will often fall through even though it is not phantom.

[VenKellie]

what abnor mole said but also best to have a prim on both sides of the border to overhang on the border while overlapping each other, i usually make them transparent. This prevents the avatar falling through the prims while making the transition from sim to sim. The moles have used this trick as well throughout the mainland roads, just turn on highlight transparency while at a sim crossing on a LL road.