Archive: 19 posts

---

Right, this is starting to really get to moe now. If i make a piece of dark matter and connect it to a piece of wood via a strength 10 stiff piston, all works as you'd expect. If I then connect the piece of wood to another piece of wood via a strength 10 stiff piston, nothing makes sense - the pistons become weak (pushable by strength 5s), they stop being properly stiff and start rotating round. All I want is the following, it doesn't work: |----| piston |------| piston |------| | dm |###########| wood |###########| wood | |----| |------| |------| Does anyone here understand why? PS. I'm building the whole thing in one go, using the grid in pause mode.

2009-04-15 18:39:00 Author: rtm223 Posts: 6497

---

Do the blocks have to both be made of wood? From my experience, a piston's capacity to behave properly is largely dependent on the weight of the "base" in relation to the weight of the "extremity". Dark Matter is an extremely good base, but I would suggest you either make the "middle" block out of metal (which is heavier than wood) or the rightmost block out of cardboard (which is lighter than wood).

2009-04-15 19:09:00 Author: Gilgamesh Posts: 2536

---

Thanks, making the middle one out of stone fixes this slightly, making the end one out of polystyrene makes the contraption stop wobbling completely. This doesn't really make sense but at least there is some logic to it! Thanks Now though, the second piston appears to have become weak. To explain, the following is a more complete contraption that I have: |----| p(10) |------| p(10) |------| |------| p(5) |----| | dm |###########| ston |###########| poly | | wood |###########| dm | |----| |------| |------| |------| |----| The strength 5 piston pushing wood (up against gravity) is stronger than strength 10 piston pushing polystyrene down. I can change the other wood to poly and it works again, but seriously, what the hell???

2009-04-15 19:31:00 Author: rtm223 Posts: 6497

---

This is actually where LBP physics become interesting. A piston OR bolt attaching something directly to a non-movable base such as dark matter or material GLUED to dark matter is really solid. As soon as you attach a piston or bolt to a non-solid base, you are dealing with the harsh realities of physics. The best way to deal with this is to engineer your object to hang and be supported (such as in my Splat Invaders levels where I hang the objects that must move left and right from pistons attached to material which is SUPPORTED by dark matter, and another piston pulling it all back and forth). Then you have another solution which is to support each section with a rod that moves up and down. It can get pretty hairy, but the design you're trying to use may not work properly using the LBP physics.

2009-04-15 19:46:00 Author: CCubbage Posts: 4430

---

[...]The strength 5 piston pushing wood (up against gravity) is stronger than strength 10 piston pushing polystyrene down. I can change the other wood to poly and it works again, but seriously, what the hell??? The strength is relative. To put it more relatively, your half strength piston of a wood block with a dark matter base is "stronger" than a full strength piston of a poly block with a wood base. Through my experimentation, beyond weight, a piston's "real strength" is also affected by its speed and by its length. A longer, faster piston is "stronger" than a shorter, slower piston.

2009-04-15 19:50:00 Author: Gilgamesh Posts: 2536

---

How big is the object you're creating? I agree with what Gilgamesh is saying, but if the material you are trying to chain together using pistons is big enough, you still may need to build a support system for it to work properly. Even IF it initially appears to work, I've seen it degrade over a period of time.

2009-04-15 19:59:00 Author: CCubbage Posts: 4430

---

If you use cardboard for both, the pistons aren't going crazy. That's how I did my 2 players door in Dig It! You also make so your blocks are made of ice and sliding on the ground. .

2009-04-15 20:09:00 Author: RangerZero Posts: 3901

---

Yeah, that's what I was saying about having it supported. I usually use dark matter and slide glass over the top, and attach the pistons to the glass. You can certainly push the other material up with the pistons in this case, however that depends on how heavy the material you're pushing up is. If it's heavy, I use 2 pistons and have the glass hang.

2009-04-15 20:13:00 Author: CCubbage Posts: 4430

---

I hang the objects that must move left and right from pistons attached to material which is SUPPORTED by dark matter, and another piston pulling it all back and forth Do you mean have the object in the middle resting on dark matter and sliding left and right on it? edit - ignore that - posted too slow! a piston's "real strength" is also affected by its speed and by its length. A longer, faster piston is "stronger" than a shorter, slower piston. I'd noticed the speed thing, length is new to me (is this because a longer piston with the same "speed" parameter measured in time, actually moves faster? Or did you test longer pistons with the time adjusted to match?) How big is the object you're creating? small, which is why I was supprised. Each of those blocks is 2x2 small units in the grid. It's a variable speed limiter - maximum length of the right hand piston is controlled by the left hand contraption.

2009-04-15 20:14:00 Author: rtm223 Posts: 6497

---

Yup, when I string materials using pistons I usually make them out of glass and slide them across dark matter. Works great for logic gates and when the pistons can work off-screen.

2009-04-15 20:19:00 Author: CCubbage Posts: 4430

---

[...]I'd noticed the speed thing, length is new to me (is this because a longer piston with the same "speed" parameter measured in time, actually moves faster? Or did you test longer pistons with the time adjusted to match?)[...] Yeah, that's exactly it. A longer piston moves "faster" in the same amount of time a short piston moves. This makes it stronger than the shorter piston.

2009-04-15 20:20:00 Author: Gilgamesh Posts: 2536

---

Take a look at this thread: https://lbpcentral.lbp-hub.com/index.php?t=t=10191 I've found a lot of these problems arise from placing pistons in series. Twisting: When you place two stiff rods or pistons in series, the object in the middle can twist. This is because, although the pistons are stiff, the object can perform both translation and rotation. (See my suggestion to Mm for a material that can only do translational movement called Buoyant Material. You can also vote for it here.) So, if you have a set-up like this: [dark matter]<----piston1---->[wood block]<---piston2---->[target] Because you cannot attach pistons directly to each other, a material of some sort, in this case a wooden block, must be placed between pistons 1 and 2. One might think this set-up would move the target left and right as the pistons move as long as they are stiff. However, that is not what happens! Instead the weight of the [target] is applied to the right side of the wooden block by the piston. This forces the block to rotate clockwise and typically results in the device breaking. There is a way to solve this problem. First you must create a track. So instead of the above you instead do: [------------dark matter----------------------------------------------------] [dark matter]<----piston1---->[wood block]<---piston2---->[target] [------------dark matter----------------------------------------------------] This prevents the rotational movement. However, it can cause additional problems due to friction. (So you might want to use glass for the tracks.) I place wheels on my block and target so they can follow the track, top and bottom, without problem. You can see a collectable example of this done with 4 pistons in series in my boss AI tutorial level. The second thing that you must do is pay attention to weight. Sometimes you can get away with less structurally sound designs if your object doesn't weight very much. However, if you have heavy, fast moving parts, they will break apart as they apply their momentum to parts of the object you did not anticipate. Rotating bolts have a similar problem. Let's look at the previous example again. What happens if you attach a heavy object with a wobble or rotation bolt to the target? One would generally expect the object to behave like a piece of dark matter (except that it moves about left and right a little bit). However, this is not what happens. Again, the object can translate and rotate! This means the bolt can actually flip the light target around the heavy object, instead of the heavy object rotating around a fixed light target! Again this will almost always break the mechanism. The trick with rotation is to make the base as stable as possible, sometimes increasing its weight so it does not suffer unexpected movements. Strength: The strength issue is another tough one that gave me a lot of grief when using pistons in series. There's a certain order that piston speeds must be attached in. Either piston 1 needs to be faster than piston 2 or piston 2 needs to be faster than piston 1. I can't remember which way it is off the top of my head. If you do it backwards then one of the pistons won't move. I believe its that piston 2 must be faster than piston 1. I'll double check when I get a chance.

2009-04-15 20:20:00 Author: dcf Posts: 468

---

Exactly... sliding it on dark matter. I usually use glass and slide it on dark matter placed below the glass.

2009-04-15 20:22:00 Author: CCubbage Posts: 4430

---

You should definitely use glass for your logic switches. It makes it so much easier for gravity - and for you. =3

2009-04-15 21:44:00 Author: SawronZXZ Posts: 463

---

dcf: I actually looked at that post but didn't think the OP was asking the same questions as me, I guess it's all related. I'll read through that hole thread at work tomorrow. sawron: Off topic slightly, but I wouldn't do something like this pistons for logic - I don't like that "pistons in series" method of AND gating, you can make a 16 input (poss more) AND gate with only one moving part.

2009-04-15 22:50:00 Author: rtm223 Posts: 6497

---

sawron: Off topic slightly, but I wouldn't do something like this pistons for logic - I don't like that "pistons in series" method of AND gating, you can make a 16 input (poss more) AND gate with only one moving part. OK - Now I'm curious...

2009-04-15 23:36:00 Author: v0rtex Posts: 1878

---

OK - Now I'm curious... Exactly what I was thinking

2009-04-15 23:43:00 Author: dorien Posts: 2767

---

I posted the 16-input AND gate thing as a separate thread as a challenge for all forum members (with solution) here: https://lbpcentral.lbp-hub.com/index.php?t=p=183384#post183384

2009-04-16 12:25:00 Author: rtm223 Posts: 6497

---

Go this this thread (https://lbpcentral.lbp-hub.com/index.php?t=t=9323) And look for Bouyant material under PENDING suggestions. It's a solution to this problem (I think)

2009-04-16 19:34:00 Author: Pinchanzee Posts: 805

Posts: 1077139    Threads: 69970    Members: 9661    Archive-Date: 2019-01-19

Aus dem Archiv wurden alle persönlichen Daten wie Name, Anschrift, Email etc. - aber auch sämtliche Inhalte wie z.B. persönliche Nachrichten - entfernt.
Die Nutzung dieser Webseite erfolgt ohne Speicherung personenbezogener Daten. Es werden keinerlei Cookies, Logs, 3rd-Party-Plugins etc. verwendet.