Speed of transport belt turns

[BurnHard]

Hello everyone,

the behavior of the speed of the transport belt turns seems very illogical to me. I don't understand why I am forced to use the faster version of the belt at the turns not to loosen up my items on the belt. It is really, really annoying to build faster belts in each corner or turn. Furthermore, what do I build in Express belt turns? ^^

I understand that the item on the outer side of the turn has to travel faster because of the larger way to travel in the same amount of time, but on the inner side it is quite contrary. The sum of both speeds is equal to two times "normal" speed.

When i see these belts in "real life" e.g. at the Airport they work pretty well, with no need for faster moving belt speeds in the corners or turns. The mechanical solution for this can differ, but the principle remains the same.

Two random examples from youtube:

http://youtu.be/iScrkKMIH80?t=25s

https://www.youtube.com/watch?v=hgd4qd2boCQ

Greetings BurnHard

[ssilk]

The behavior of the speed of the transport belt turns seems very illogical to me. I don't understand why I am forced to use the faster version of the belt at the turns not to loosen up my items on the belt.

Basically every item covers an area and this cannot be covered by others. In the inner side of the belt is just not so much space, the density is inside higher than outside. Not so dense, not so much items.

It is really, really annoying to build faster belts in each corner or turn. Furthermore, what do I build in Express belt turns? ^^

No not at every turn. I use the turns to reduce the maximum throughput. You can also use two splitters, one before the turn and one after. And when you don't need it, you don't need to place it. Remember always: two slow basic belts have a bigger throughput than one fast.

I understand that the item on the outer side of the turn has to travel faster because of the larger way to travel in the same amount of time, but on the inner side it is quite contrary. The sum of both speeds is equal to two times "normal" speed.

As said, every item has a collision box. The item must move to the side, before the next can follow. Look in highest zoom to it and it can be seen.
When the items are not so dense, then they work exactly like on an airport. But believe me - I saw that one time: when the luggage is too dense, it behaves exactly like Factorio belts.

[kovarex]

ssilk: these are the reasons why it works the way it works, but it doesn't mean we can't hack it a little bit to make ti work better.

I already did some small hacks to make merging belts work better version or two back.
The thing, is, that there are some constants and formulas defining the movement in turns, and these can be tweaked/bent a little to make it work more smoothly.

[BurnHard]

Well even if the density on the outside IS lower while in the turn, I can't see any reason why the density AFTER the turn can't be the same as before. At the moment, the game rather seems to throttle the throughput down artificially.

Yes, it is dense on the inner way, so lesser items per time per distance, BUT the way ist very short. So in reality the item in the inner side ony "blocks" this segment for a much shorter time than now similated in the game. The Speed over ground on the belt may differ, but the angular velocity remains the same on every point of the turn = Same angular velocity=same throughput of items per time. This even works with the existing collision box sizes like it does when you insert a faster belt).

Beside that whole technically thing I can't express better because english is not my native language, what speaks for the actual (in my eyes bugged design of belts corners) game-balance wise? All those workarounds with splitters and faster belts seem rather "mehhh"

Thanks for reading and considering

[ssilk]

ssilk: these are the reasons why it works the way it works, but it doesn't mean we can't hack it a little bit to make ti work better.
I already did some small hacks to make merging belts work better version or two back.

Phuuuu. I really though my benchmarks is not reliable anymore... I measured the difference and wondered and searched for a bug lst week.

Btw. To calculate exact results, I could need a belt, which is "switchable", like an inserter. There is really no other way, because otherwise (using inserters) I will always include items, which are outside of a test-drive and the result is 4-10 items too big. Eventually we could have a door, which you can place over an belt?

And another thing would be a Nil-device, which either can output a endless stream of items on a belt (a nil) or eat up any number of items on belts. But I think I try out to make a mod for this second. But the first cannot be made as mod.

And no, this has very low priority...

[n9103]

Just injecting a little IRL to the discussion, perhaps shedding light on the perceived irregularities:
RL Assembly plants and other situations that use conveyors VERY rarely are stuffed to anything remotely close to capacity.
They also often don't used powered conveyors in turns, instead relying on gravity, inertia, or semi-specialized machinery. (The beer bottling rig that rinses/fills bottles as they round a corner comes to mind)

Source: How It's Made documentary series

[ssilk]

...I can't see any reason why the density AFTER the turn can't be the same as before. At the moment, the game rather seems to throttle the throughput down artificially.

You drive behind a car, let's say you are very near, 10 meters with 50 km/h. Then comes a turn. Your frontman brakes and you need to brake too, distance is now only 1 meter. Because you have to brake much earlier, than your frontman (because his car has a length) and because of the short distance you had before, the distance after the turn to your frontman after speeding up back to 50 km/h is suddenly 20 meters. Because you needed longer to turn. If you want to avoid that, you need to drive faster in the turn or you make the turn not so strong, or - and I think this is a part of what kovarex want to tune it, you make the cars shorter in turns, and place tires, so that the turn is rounder.

Beside that whole technically thing I can't express better because english is not my native language, what speaks for the actual (in my eyes bugged design of belts corners) game-balance wise? All those workarounds with splitters and faster belts seem rather "mehhh"

how can you say that? it's like in reality!!

[BurnHard]

They also often don't used powered conveyors in turns, instead relying on gravity, inertia, or semi-specialized machinery. (The beer bottling rig that rinses/fills bottles as they round a corner comes to mind)

Something like this http://www.grasshoff.de/imagecache/800x ... bahn_1.jpg

[BurnHard]

You drive behind a car, let's say you are very near, 10 meters with 50 km/h. Then comes a turn. Your frontman brakes and you need to brake too, distance is now only 1 meter. Because you have to brake much earlier, than your frontman (because his car has a length) and because of the short distance you had before, the distance after the turn to your frontman after speeding up back to 50 km/h is suddenly 20 meters. Because you needed longer to turn. If you want to avoid that, you need to drive faster in the turn or you make the turn not so strong, or - and I think this is a part of what kovarex want to tune it, you make the cars shorter in turns, and place tires, so that the turn is rounder.

Hm, following your logic, the distance of my car AFTER the turn (If I brake and accelerate the exact same way) is exactly the same as before, 10 meters. And this is absolutely independend from the duration and speed of the corner. In your "real case" presented you would brake more and accelerate slower, because you don't want to cause an accident if the front car has to stop for whatever reason. Why do you need longer to turn if you do have the same speed (yes, lower distance to front car, but same speed)? Transfering to all the ores on the belt: They dont need to keep a safe distance because of possible collision, so this leads to example numer two



Image yourself at a large theme park, ticket sale, disco or whatever. Where a lot of people wait at some entrance. All persons are packed together, touching each others bodys (you know what I mean ) Speed maybe a ten Meter per minute. Now this whole bunch of people has to wind around a corner. Never, ever have I seen in this kind of situation to gain space AFTER the corner. yes, maybe while turning some centimeters are gained, but right after the corner, after the turn, there immediately is this warm cosy feeling of other human beeings packed together like sardines in an can

I understand that this is low priority for the devs, but can't it be fixed "quick and dirty" by multiplying the general beltspeed for every belt-type by for example 1.5 in the corners?

[n9103]

Something like this http://www.grasshoff.de/imagecache/800x ... bahn_1.jpg

yep.

[ssilk]

Hm, following your logic, the distance of my car AFTER the turn (If I brake and accelerate the exact same way) is exactly the same as before, 10 meters.

No, because then you would crash into the car ahead.

And this is absolutely independend from the duration and speed of the corner. In your "real case" presented you would brake more and accelerate slower, because you don't want to cause an accident if the front car has to stop for whatever reason. Why do you need longer to turn if you do have the same speed (yes, lower distance to front car, but same speed)? Transfering to all the ores on the belt: They dont need to keep a safe distance because of possible collision, so this leads to example numer two

Hum. If the world would behave like so, we had no traffic jams and no car accidents. I really would like that, but reality is much "harder".

Image yourself at a large theme park, ticket sale, disco or whatever. Where a lot of people wait at some entrance. All persons are packed together, touching each others bodys (you know what I mean ) Speed maybe a ten Meter per minute. Now this whole bunch of people has to wind around a corner. Never, ever have I seen in this kind of situation to gain space AFTER the corner. yes, maybe while turning some centimeters are gained, but right after the corner, after the turn, there immediately is this warm cosy feeling of other human beeings packed together like sardines in an can

Well, hum, it's not comparable. Humans run themselves and can run much faster than 10m/min. So the gap is closed.

But you can see this on an empty check-in, when a whole bus of people comes at once. You have this stupid lanes before the accounts and need to walk zigzag. And you can watch here very well, that the crowd jams at the first corner and after that corner there is no big jam anymore, even if there are many more corners. This is because this corner limits the density of the passengers, because in the corner they cannot walk so fast and the passenger behind needs to stop and so on.

I understand that this is low priority for the devs, but can't it be fixed "quick and dirty" by multiplying the general beltspeed for every belt-type by for example 1.5 in the corners?

I don't understand, why you are so keen on that. This is part of the game: try to built straight belts. Otherwise you should built two line or more. There are many tricks. But I would welcome a little speed up, so, that using a fast belt in the corner is exactly like using two basic (which is currently not the case which is a little bit unawaited, but understandable).

All in all I think the belt physics is so rich of small details, that I won't kill all of the "strange/curious" behavior and instead I am willing to explain it in detail on wiki, but before that it should be a little bit more stabilized, because it's no fun to throw away all of the explanations, if it changes in the next version.

[ssilk]

They also often don't used powered conveyors in turns, instead relying on gravity, inertia, or semi-specialized machinery. (The beer bottling rig that rinses/fills bottles as they round a corner comes to mind)

Something like this http://www.grasshoff.de/imagecache/800x ... bahn_1.jpg

Good example!

Even here the packets lose speed in the corners, because they have to turn and need then more space on the belt (always only valid, if the packets are so dense, that they touch together!). The speed reduces - depending on radius of the turn, up to SQR(2)!

In Factorio the items doesn't turn and need so a lot more space.

I would say it should behave a little bit more like in the pic, but I won't remove this effect, because it isn't realistic.

[BurnHard]

Thanks for you replys

Do you know the "Grand National"-Ride at the pleasure beach resort? There are two rollercoaster lanes beside each other, think of the two lanes on an transport belt. Both trains do have the same speed when taking a corner, the waggons on the inner lane of the turn start to get ahead because of the shorter way, but their absolute speed is not faster or slower (ignore the accelerating phases while dipping down).

http://youtu.be/9aw08LhxNIU?t=1m00s

But nevertheless none of the waggons has to accelerate or brake, all the waggons in one lane stay together (even if they wouldnt be linked). All wagons on the same lane have the same way to go, the outer lane waggons just arrives a secon later at the station, but the rate of "waggons per minute" is the same (throughput of goods)

Your car example: Think of taking the corner without braking or accelerating (the only reason to do is because the limited traction of your tires at high speed), thats what goods even on free rolling belts do (the only force is gravity, on an even surface no kinetic energy is taken away or induced.

Even here the packets lose speed in the corners, because they have to turn and need then more space on the belt (always only valid, if the packets are so dense, that they touch together!). The speed reduces - depending on radius of the turn, up to SQR(2)!

Well even that I see different. Even if they are packed close together: Regardless of the lane: one item per second goes in, one item per second goes out. Think of pushing eg two toy trains on two lanes with 10 waggons from behind through such a corner. Halfway, with 5 waggons through the corner, the Locomotive of the inner train may be one waggon ahead, but the last waggon of the trains are still beside each other. I am to lazy to draw a picture, I hope you understand what I mean.

The time the item on the inner lane remains on the "turn"-section is just shorter, but it absolutely has the same speed than the item on the outer lane. This outer lane-item just needs more time because of the larger way. If the way on the outer lane is say 3 times larger, than simply 3 times the items can be stored on the lane itself.

Think of a fully loaded belt in factorio starting to roll, on the front item red and item blue beside each other. Now, after a turn, both items in factorio are still beside each other, but THAT is impossible without extreme acceleration of the outer lane item, it should just lay some distance behind. This does not affect the number of items such turn can transport, it just means the time the first items start to drop in is a few seconds later.

[ssilk]

Well, this is not comparable, because the wagons are fixed. They behave like one wagon/item.

When you look exactly, the problem IS NOT that one item is slower in the curves. Or that the inner curve is shorter. And you can see that clearly: take two chests on each side of a belt, use basic inserters to fill the lanes of the belt and make a curve. As you already described, the items keep directly besides, they don't lose speed, compared to the lanes, this is as they are both on one belt, which is exactly what we want. This is correct behavior.

The effect cannot be seen, when the items have such a big distance. But (!) when you have so many, that they touch each other, then the effect is as I described. The inner items need more space, because the inner line is shorter. They stop the items after them and this leads to a small jam and the effect is, that after the curve, the items are not so dense.

Don't mix density with speed!

This effect is just like in reality, when you put things on a belt, but not so extreme, but I already described, why this is in Factorio the case.

And to my example with the car: it is a little bit ugly. I want to replace it.

Take two cars. They can drive only 10 km/h and the distance is 10 cm. Now in the curve, the front car turns. This leads to the effect, that one side of the car gets nearer. Let's say 5 cm. Then - to keep the safety distance - the second car must brake.

Uffff... And if that doesn't help I will make a drawing, that you see that this effect is real.

[BurnHard]

Beside all that theoretical things :

In the end it's just the question what's best game balance wise. Do the devs want to force the player to build only straight belts to maintail full density on the belt after the turn; and do they want to the player to develop workarounds for this "problem" with splitters and faster belt in the corners instead of just be able to build "clean" and simple conveyour belt lines.

[Dakkanor]

i once did a military based course which had trainees(including me) grouped up 3 platoons of 30 each, it was a course for civilians to learn discipline and life skills so its maybe not what would be seen in real life, but they often had the trainees marching in 3 columns. my point is that they had to teach us quite rigorously on how to turn corners. the people in the middle would march at their normal speed around a corner, the people on the inside would march about half speed around the corner and the people on the outside would speed up. this was so that we would be marching with each row staying level to one another, and by removing the center i believe it clearly defines an optimal setup for belts in factorio.

with a perfectly smooth flowing factory ideally there should be a small gap between each item on the conveyor, like this there shouldn't be any slowdowns on the corners to my knowledge, as that small gap means that there is room for compression between items, because the inner part of the turn has to bunch up, if there's no gap it jams instead of bunching up, this is what causes those noticeable slowdowns

personally i prefer to slightly over produce each earlier stage, because i like the look of full belts waiting to be processed, i also tend to muck up somewhere and forget about it, so those full belts give me a buffer to fix problems without and help me gauge my flow control. so i am not too bothered by belt slowdown, i simply make as few turns as possible, ending up with long straight backbones for my factories to be built off.


for a programming standpoint would it be possible to push the turn into a slightly wider arc? this would end up having the outer curve practically hugging the outside edge, but it might give enough expansion to cancel out the jamming.......

[ssilk]

@BurnHard: Yes, they can do this. No I don't want that in general, because I want a realistic game and that means, that some details work different than expected by the most players.

@Dakkanor: "this was so that we would be marching with each row staying level to one another, and by removing the center i believe it clearly defines an optimal setup for belts in factorio."
Excatly this is the behavior! But another effect comes in, because the items on the belts have a square collision box and don't turn (I mean because difficult to calculate, too slow for CPU), they block much more the items behind as wanted.

And now I found the thread again, which displays this last thing very well:

https://forums.factorio.com/forum/vie ... =side+belt

[BurnHard]

@BurnHard: Yes, they can do this. No I don't want that in general, because I want a realistic game and that means, that some details work different than expected by the most players.

As realistic as Laserturrets in a personal modular armor?
Or simply dropping coal and ore in a furnace and you can take out cold metal plates one second later?
Crafting intelligent chests and inserters and other things in a matter of 2-3 seconds?
Beeing able to carry tons and tons of materials, hundreds of capacitors or solar modules, whole trains etc?

hard to say how realistic a game should be or can be

[kovarex]

@BurnHard: Yes, they can do this. No I don't want that in general, because I want a realistic game and that means, that some details work different than expected by the most players.

As realistic as Laserturrets in a personal modular armor?
Or simply dropping coal and ore in a furnace and you can take out cold metal plates one second later?
Crafting intelligent chests and inserters and other things in a matter of 2-3 seconds?
Beeing able to carry tons and tons of materials, hundreds of capacitors or solar modules, whole trains etc?

hard to say how realistic a game should be or can be

Yes, the game is not aiming for realism, but good gameplay, if we hack a the movement in turns to work better, it is ok.
As it was asked, the question is, what should the gameplay effect of turns be, I personally don't have problems with turns and I use usually red belts for important parts of the factory, but maybe I don't produce so much

[ssilk]

Yes, currently if I have so much, I built a second belt and with v0.7 I think much more about using a train instead...

I think it is more or less good as it is (I already said I would support a little tweaking) and if someone want to squeeze the last 10-20% out of belts, he needs to tweak a lot and use high capacity-tricks.