My Sadrith Mora inpsection
Posted: 29 Jul 2016, 23:32
So I traveled to Sadrith Mora and noticed I had low fps. I´ve heard of people complaining about physics going up in there, but nobody ever got to the root of it. The physics went up to 100 compared to the low 30 of Balmora.
Curious to see what was causing it, I enabled the collision grid and started inspecting. It seems to be a combination of two things. There are like 6 Telvanni guards who aggressively wander around the place. This is fine on its own, as there are many wanderers in Balmora too, but the way the path they wander on can be problematic.
If you´ve ever explored Sadrith Mora, you´ll know that there are 4 outside shops. I think 1 sells armor, the other weapons, third sells potions and the fourth sells general items. The general items has some lootable urns with no collision mesh.
The difference here is that the Telvanni guards wander around these urns and other misc items whereas in Balmora the urns are in corners of houses where NPCs don´t go. Similarly there are small outside shops in Gnisis, but these don´t cause trouble because they are against the side of the temple wall instead of being in the middle of the street.
But perhaps the biggest offender here are the slave cages, past which the Telvanni guards occasionally wander.
These cages do have a collision mesh. Let´s have a look. The one on the left is the mesh and the one on the right is the collision mesh.
It seems like the upper and lower part of the rods were simplified into a wall, but for some reason the middle part was left as-is. In the next screenshot I´m going to walk against 2 rods and also against the ground and also the lower wall of merged rods. Let´s see what happens.
I can get my physics as high as 250 by walking against it like that for 2 seconds. A single actor colliding with 8 faces = 100 physics. A Telvanni guard won´t explicitly walk against it like that, but he will occasionally breeze against it and cause collision to jump up and kill my poor frames. While not the only offender here, it is still a pretty big one.
It seems like OpenMW physics in general goes out of whack if you have more than 1 NPC walking near something that isn´t a simple cube.
So what´s the lesson here? Don´t place a lot of wandering NPCs near objects with no collision mesh. If you have issues in Sadrith Mora, the best course of action is to disable the 3 guards that frequent this slave shop + weapon seller potion seller + general item shop and you will shave off a significant amount of physics.
Curious to see what was causing it, I enabled the collision grid and started inspecting. It seems to be a combination of two things. There are like 6 Telvanni guards who aggressively wander around the place. This is fine on its own, as there are many wanderers in Balmora too, but the way the path they wander on can be problematic.
If you´ve ever explored Sadrith Mora, you´ll know that there are 4 outside shops. I think 1 sells armor, the other weapons, third sells potions and the fourth sells general items. The general items has some lootable urns with no collision mesh.
The difference here is that the Telvanni guards wander around these urns and other misc items whereas in Balmora the urns are in corners of houses where NPCs don´t go. Similarly there are small outside shops in Gnisis, but these don´t cause trouble because they are against the side of the temple wall instead of being in the middle of the street.
But perhaps the biggest offender here are the slave cages, past which the Telvanni guards occasionally wander.
These cages do have a collision mesh. Let´s have a look. The one on the left is the mesh and the one on the right is the collision mesh.
It seems like the upper and lower part of the rods were simplified into a wall, but for some reason the middle part was left as-is. In the next screenshot I´m going to walk against 2 rods and also against the ground and also the lower wall of merged rods. Let´s see what happens.
I can get my physics as high as 250 by walking against it like that for 2 seconds. A single actor colliding with 8 faces = 100 physics. A Telvanni guard won´t explicitly walk against it like that, but he will occasionally breeze against it and cause collision to jump up and kill my poor frames. While not the only offender here, it is still a pretty big one.
It seems like OpenMW physics in general goes out of whack if you have more than 1 NPC walking near something that isn´t a simple cube.
So what´s the lesson here? Don´t place a lot of wandering NPCs near objects with no collision mesh. If you have issues in Sadrith Mora, the best course of action is to disable the 3 guards that frequent this slave shop + weapon seller potion seller + general item shop and you will shave off a significant amount of physics.