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Wandering Soulstar

Physical Prims Question

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Hi All,

Have never used Physical Prims so far, other than playing with the property to drop prims on friends :-) ... but I am doing a build and had an idea that I thought I could use physical prims but just not working and want to ask if anyone knew whether what I wanted to do was even possible, and if so, what I was doing wrong.

In short I am building an elevator. What I'd like is for there to be a fast descent option and thought to do this with physics rather than code. There will bill a tall metal cylinder which the elevator would travel up and down using electromagnetism .. so the elevator is connected to another cylinder (hollowed) which rides up and down the main one. To see if this would work I created the main pipe (with a base) as will as the hollowed one (sleeve) that goes around it .. but from there things just did not work.

First tried with the base, pipe, and sleeve set to Physical .. but the sleeve went set did not fall straight down along the pipe, but rather out as well. Imagine that is because the 'hollow' is not trully hollow in the physics engine.The only way I can get the sleeve to fall straight is if I make it phantom as well as physical .. problem there is that it just keeps falling until it hits the ground .. as well having the elevator phantom would make it a bit hard for anyone to use it ...

So .. is there something I can do (without code) or do I just need to give up on the idea?

 

Thanks in advance!!

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Do not set your envelope to physical, it is not supposed to topple over when planes crash into it - only your elevator needs to be physical to be bouncing of nonphantomwalls and affected by gravity... and give the hollow envelope some remaining wall width for the physics engine to work propper.

Edited by Fionalein

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Appreciate the reply Fionalein, but do not quite understand. My idea was that the sleeve is what connected the elevator to the pole and thus would keep it on a straight track down .. for which it would need to be physical to fall .. otherwise I'd have to move it with code and so negating the use of Physical. Something you said though gave me an idea that I am gong to try as soon as RL lets me get back in-world.

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Unlike RL, in SL, the drag model is uniform. So, a "physical" object will fall straight down, unless ya apply a force or impulse that isn't vertical.

 

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Ya posted as I was typin. Scripting a non-physical object might actually be less of a server load. And it gives ya more control.

 

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slideonrod.thumb.png.91ef4f39e3c0c6fb87ff4970cfc3659f.png

The physics engine in SL is low precision. A tight-flitting sleeve around a rod will not work. Allow a gap of 10-20cm,and it might work. I just tried. It will even slide down a tilted rod. But it also may go flying off.

People have done bearings with SL physics, but they're not reliable. I've seen a Ferris wheel built that way. They need a script to detect errors and put them back into position.

Not the right solution for an elevator. Look into keyframed motion. See llSetKeyframedMotion

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