Physics for Noobs

[Michael Timeless]

I'm curious. I have brought two houses in worlds with me. Both have staircases that I have used for years both in SL and IZ. I know that SL switched to Havoc. But I am using the ODE physics here and my avatar and a friends avatar can no longer walk up the stairs. I haven't used bulletphysics before and don't know if this would affect it. I have tried this experiment both in standalone sim mode and megaregion mode without luck and would hate to have to redesign dozens of staircases. Any suggestions other than invisible ramps?

Michael Timeless

[Dot Matrix]

Whereas SL allows avies to go up steps 0.5 m high, 0.3 m seems to be the limit in OpenSim.

And invisible ramps seem to be the easiest solution.

[Ilan Tochner]

I would advise against using BulletSim at this time. It still suffers from various issues, including much higher occasional CPU usage than ODE (maxing out the CPU causing sim-wide lag).

The recommended solution for stairs optimized for Second Life, that don't enable avatar climbing in OpenSim, is to use invisible ramps.

[Michael Timeless]

So as I was saying I need to look into a lot of invisible ramps....

[Dot Matrix]

I know it's a pain, but it works, and you only need to do it once if you remember to take a copy of the modified building.

For example, the Library on Intersections, based on Amiryu's lovely Matsumoto Castle which was originally built in SL, has lots of stairs and needed ramps on all of them.

To do this I found the base slope prim, unlinked it (carefully!) from the rest of the build, copy-dragged it roughly to the front of the stairs, switched the texture to plain for greater contrast, then linked the prims (VERY carefully) back together in the order ramp--base-slope--structure. Then I isolated the ramp in the structure and made it invisible.

[Michael Timeless]

Dot/et All

It's all good and part of the learning curve. I think one of the things I'm enjoying about Kitely is learning workarounds for things. In almost every case I think I became complacent in SL and this is reawakening the entire concept of playing again. The one thing I like the most is that the people have been so nice and it's nice to have a forum where people answer questions. SL was once like that - I think those helpful people all moved here.

[Mike Lorrey]

There are issues with ramps as well if they are too steep. For instance, the classic spiral ramp staircase made with a single tube prim, which is exceedingly easy to walk up in SL, is a bit more difficult in OS with ODE but workable in most conditions, but Bullet puts a limit on how steeply your ramp can go. I haven't measured it precisely, but something around 2-3 rotations in 22 meters is the limit for a 5 meter diameter spiral ramp.

[Brayla Sana]

To make my steps work in Opensim, I upload them with a ramp for a physics model. Otherwise, not only is there a chance they don't work at all, but they make an annoying thumping when you walk up and down them.

[Mike Lorrey]

To make my steps work in Opensim, I upload them with a ramp for a physics model. Otherwise, not only is there a chance they don't work at all, but they make an annoying thumping when you walk up and down them.

And you can add a four vertex plane with its own transparent material to any mesh steps to ensure the physics model is accurate to that.