Physics Shape goes drastically wrong, reliably on moving objects when I'm moving
tracked
Journey Bunny
Classifying this as a server bug, since it happens on all viewers, to all users, and when the physics shape "changes" automatically (and then corrects itself automatically), the change affects ALL avatars.
Walking towards a door while touching it causes a physics shape bug.
This happens pretty reliably. Occasionally it doesn't happen, but at least 9/10 times.
Whenever I'm in motion and click, and the doors start moving, the physics shape goes wrong.
Sometimes the physics correct themselves as soon as the doors finish closing. Sometimes it takes several minutes. Sometimes, right-clicking and choosing Edit Linked causes an immediate fix.
I see there's multiple Details boxes on Canny, so I'll put the rest below?
Edit: Oh, interesting. Hopefully LL can see the steps and the link to the video!
Log In
Maestro Linden
tracked
Uggo Vieria
hello, I use linked doors in my builds and have never noticed this issue but my door script sets the door to PRIM_PHYSICS_SHAPE_NONE before opening and back to PRIM_PHYSICS_SHAPE_CONVEX after closing, which I initially added to prevent doors with lossy physical shape to block the way when they are open.
Might be worth trying and see if it helps.
Maestro Linden
needs info
Hi Journey Bunny is this issue still reproducing for you? I visited your SLURL, and haven't seen anything like the surprise collision behavior when opening the door via Touch while walking (I tried about 30 times). My tests were with avatar walking & touching the doors outside the house, while another walked around the lower level of the house.
That said, from your video and description of the bad behavior, it does indeed sound like the prims of the house is reverting to a convex collision shape when avatars are pushed out. This switch to convex physics can occur when there are excess collisions between a linkset and other objects in the region, as a way to prevent the sim performance from dropping. With the way the doors are currently designed, (moving as child prims in the linkset when opening/closing), the physics shape of the entire house needs to be rebuilt by the simulator is rebuilt many times, which impacts physics performance and generates collision events between the house and any nearby avatars or other physical objects. You would see better performance (more snappy collision behavior as the doors open/close and less likelihood of surprise convex behavior) if the doors were separated from the house linkset.
Journey Bunny
Maestro Linden Hiyaaa! Yep, first try, reproduced. I'm on Alchemy viewer right now, but I can try again later with SLV. But yes, got it to happen immediately, with just me on the parcel. I can arrange to meet up with you there if needed!
Separate, soft-linked doors would very likely solve the issue, but it's a large house (one I'd like to market, even) with 9 doors on it; if anyone were to attempt to move or rotate the building, getting all the doors into the right spots is rather more difficult, so I went with the linkset. I didn't realize the entire physics shape is rebuilt continuously--that sounds evil! But the change in shape to Convex still seems like a bug :0
Maestro Linden
Journey Bunny: When you reproduce the issue are there any other avatars or physical objects near it? I still can't reproduce the issue.
Aside from testing with only my avatar approaching the doors, I also rezzed a few objects in the lower level of the house containing the 'jumping torus' script (shown below) in an attempt to agitate the physics engine. They didn't change the behavior I saw when walking and touching the doors..
default
{
state_entry()
{
// make it a 1.5m default torus
llSetPrimitiveParams([PRIM_TYPE, 4, 0, <0, 1, 0>, 0, <0, 0, 0>, <1, 0.500000, 0>, <0, 0, 0>, <0, 1, 0>, <0, 0, 0>, 1, 0, 0,
PRIM_SIZE, 1.5*<1,1,1>, PRIM_PHYSICS, TRUE, PRIM_NAME, "jumping torus"]);
llSleep(llFrand(1));
llSetTimerEvent(1.0);
}
timer()
{
llApplyImpulse(<0,0,1>, TRUE);
llApplyRotationalImpulse(<0,1,0>,TRUE);
}
}
Journey Bunny
Maestro Linden I'm so confused! I'm sorry about all this--I just log in and walk and click and it does it every single time... There's nothing else, just that building on an empty parcel to test, by myself.
Just did it now, this time in SL viewer (previos vid was in Alchemy)
You can see that I start walking, position the mouse, and then, once I'm up to speed, I'm holding down the walk button when I click~
Edit: Follow up details from some creators on Discord:
Zi Ree (Firestorm) —
If you stand still, physics changes that intersect your avatar don't kick in immediately.
Tayln Osbourne —
for objects, physics is physics, but for agents most of its physics is handled by a special player handler with specific rules
Maestro Linden
Journey Bunny: Okay, let's try something else. To rule out something with your avatar (like a scripted attachment) triggering this bug, could you try replacing your current avatar with 'Elizabeth' (picked out of a hat) from Library and see if the bug reproduces for you in that case?
For what it's worth, I tried the Elizabeth avatar with an alt account, and still cannot reproduce the effects shown in your videos.
Journey Bunny
Maestro Linden Hiya! I found the Elizabeth avatar, and got the issue again first-try, in SL Viewer: https://gyazo.com/9e1592d390001e96fd8102c00d158a1e