Unable to walk through door or ascend staircase

[Colette Meredith]

Hello,

I've been using SL for years (since 2009) and have had property in Blumfield since then. Recently, I've begun having a peculiar problem but, as it was initially only in one spot, I did not bother to ask for help. Also, it seems in that one spot to be intermittent. Now, it's popped up on another of my Blumfield parcels so I am hoping someone can advise me.

Initially, I was unable to ascend stairs on one of my parcels (two different staircases, in two different builds). I checked to make sure there are no transparent blockages. There were not. This has occurred off and on now for months but had remained isolated to that one block of land. Now, it's happening on another parcel, where I cannot enter or exit via the door of the cottage. It's as if there were a transparent wall blocking me but there is nothing there that I can locate, either by making transparencies visible or by checking all my objects in Linksets to make sure there's nothing extra.

I use the SL viewer, by the way, and have Nividia Ge Force  GTX 1060 6GB card (see system info attached). 

Thanks very much to anyone who can help.

Edited October 12, 2018 by Colette Meredith

[Qie Niangao]

Among my discoveries in this adventure: Mainland sims include both a Bloomfield and a Blumfield.

The cottage door is now phantom and I don't seem to have any trouble getting through it now, open or closed. The stairway in the Garden District Townhouse seems fine, but something's not quite right at the top and bottom of the stairway at "Bookshop 12-October-2018" but I'm not entirely sure what.

My new-fangled raycasting gadget didn't help, so (another discovery) I acted like a griefer and brought prims onto a no-build parcel from a build-enabled parcel across a no-object-entry parcel (don't ask), and pushed a physical (purple) cylinder around, getting it to bump into some sort of barrier about the same spot at the bottom of the stairs where my avatar had to hop over an invisible hurdle. I couldn't tell for sure what it was colliding with, but it seemed to be hitting a couple paintings, "Sugar Skull 2" and "Sugar Skull 5", when they really shouldn't be in the way. So I built a thin (green) "shield" box to guard them, but still they caused collisions, so their "convex hull" physics model seems to be larger than is apparent. I'd suggest setting them phantom to see if it matters at all, but I don't really think they're the actual problem here.

The finials of the railing uprights are where I seem to "feel" the barrier. What doesn't make sense, though, is that they appear to be simple prim constructions: a double-dimpled hollow sphere perched atop a carved-up torus. I don't know any reason they should pose a problem. They're linked with the whole bookshop assembly, though, so they'd need to be unlinked to be made phantom, if you want to experiment with that.

Edited October 12, 2018 by Qie Niangao

[Pamela Galli]

You may have unlinked, and maybe relinked, your house.

[Colette Meredith]

Pamela, I definitely did do that, at least with the second house, but the door was never linked to begin with, and still works fine as far as opening and closing. I just can't walk through! So, what do you recommend to fix it? Is there a fix? Cheers, Colette

[Elise Banx]

check so the walls where the doorway is and the stairs, arent convex hull... 

[Callum Meriman]

The door and door frame look to be sculpts. Relinking might have messed them up. Can you rez a new copy?

As something unrelated: Have you applied materials to the door frame? Because the LI for it is pretty high.

[Qie Niangao]

Sure sounds as if some things have started using Convex Hull as their Physics Type. The convex hull of a doorway is basically a wall. A staircase might become a solid blob of completely invisible barrier. (Not transparent, but rather completely invisible.)

To get a hint what's in the way, one could script-up a thing to wear that might notice what it's bumping into when it gets collision events, or you could try to work out what's being displayed with one of the special "bounding boxes" debug display modes (which has never worked for me at all), but ideally it'll just be obvious what might be in the way when its concavities are secretly filled-in.

[Colette Meredith]

Hello, everyone, and thank you for your responses. Elise, thanks for that suggestion. I have checked because I suspected you were correct, but no, they are not convex hull. (Also, weirdly, the stairs at the other parcel are fine today but I have been unable to ascend or descend them the past several days.)

Callum, thanks so much for having a look. I have not added materials to the door frame of the cottage, no. However, the problem began here after I unlinked the floor from the house in order to take a copy of it. Then, I changed the floor texture and relinked it to the house. The door was not involved, as it was never linked to the house to begin with; but, it's where the problem is so I must have stuffed up something.

Qie, I agree with you but I cannot find anything that is Convex Hull. Weirdly, though nothing has changed with the stairway, I can walk up and down it just fine today! I will see if I can get the bounding box to work; if not, I guess I will have to rez a copy of the cottage and re-do all the mods I've made over time.

Thanks again!

[ChinRey]

43 minutes ago, Colette Meredith said:

The door was not involved, as it was never linked to the house to begin with; but, it's where the problem is so I must have stuffed up something.

It's not about the door, it's the doorway, that is either the doorframe or the wall around it, and for the staircases, it's the floor with a hole in it.

I assume we are talking about mesh here (I'll say something about sculpt later in the post). Making a thin mesh with a hole in it (such as a doorframe, a wall with a door opening or a floor with a stairwell) can be a bit tricky and something many inexperienced builders get wrong. One way to "repair" meshes with faulty physics, is to set their physics shape, not to convex hull but to "none" (which is the same as pahntom, only it works on individual parts of a linkset) and then add some invisible prims for the physics. Experienced mesh makers won't usually use the trick since, partly because it adds to the render weight and can add to the land impact. But mostly because it gets messy if you unlink the build and that seems to be what happened here.

Try to hit Ctrl+Alt+T to reveal invisible items. If there are some of those inside the wall and/or the floor, that's where the problem is and the solution is to set those walls and/or floors to physics shape none. If it's mesh, it's probably a good diea to set the physics shape of the doorframe to none in anyway, it's not as if it actually needs physics.

There is a similar problem with sculpts and it can be a bit harder to handle. it is not possible to make a hole in the physics shape of a sculpt so the invisible prim trick is the only solution for those. Setting the phsyics shape to none works for sculpts too. But due to a quirk in the way land impact is calculated, it can change the LI significantly. Usually it will actually reduce the LI of a linkset but sometimes it will increase and if that happens, the only solution is to unlink the sculpt and set them to phantom the old fashioned way.

[Qie Niangao]

Sculpts are also special in that their non-phantom physical bounding box can be fantastically larger than the visible extent of the sculpt. There's a popular grass creator that used these hugely outsized sculpts to preserve a more detailed LoD far further than the visible size of the object would warrant, and this is forever tripping-up my traffic probes that use raycasting to detect objects on the SLRR right-of-way.

That reminds me of another raycasting project I've been working on that (unfortunately) finds the surface of those invisible convex hull bounding boxes. That's actually a problem for the project, as it is for the traffic probes, but in this case it might be an accidentally useful tool in tracking down whatever is blocking the path, if all else fails.

[Pamela Galli]

I get this same request about once a week, always because someone meant to unlink something, but unlinked the whole house. Sometimes they relink , but the damage is done.  I send them here for an unlinking lesson:

https://lagalleriasl.com/editing-linked-prims/

The only fix is to delete and re Rez.

Tip: Every time you make a modification, take a copy. Make sure the copies have a different name from the original.

Edited October 12, 2018 by Pamela Galli

[Colette Meredith]

Thank you ChinRey, Qie, and Pamela -

I ended up deleting and re-rezzing the cottage and redoing my mods. As you can tell, I am not an experienced builder, just an amateur. I know some things but am missing a lot! 

I am going to save all of your advice for next time I get stuck.

Cheers.

[Colette Meredith]

Qie, 

Thank you so much for all the effort you put in troubleshooting! I only just saw your post on that, as I'd overlooked it before. I know the bookshop staircase is weird weird weird. Some days, I cannot walk from the top or bottom, some days only the bottom, yet I can hope over whatever hurdle is there which I cannot find.