hydraulics are crap

[Henry Collingwood]

why oh why oh why don't the hydraulics expand and contract at the same rate? also why do they expand a little then jitter then expand a bit. you know hydraulics are an incredibly smooth system. these hydraulics are crap and are really spoiling the game

[Christian_Akacro]

The problem is that it literally takes more time for a 4m hydraulic to expand than a 1m, for example. So it's unavoidable that longer hydraulics will take more time to complete as far as rate of expansion/contraction is concerned.

We are trying to smooth hydraulics out so they don't jitter so much. Several improvements have been made to them in previous updates and we're working on resolving the remaining issues with them.

[Koitenshin]

I hope you fix it, because this is crap. My bridge will break apart in one simulation then work perfectly fine the next depending on how much jitter there is.

[bolt986]

@Koitenshin, post your design. Usually you can cut back drastically on the amount of jitter by just attaching the hydraulics to a different place on your bridge.

I suspect you are trying to lift a large portion upwards from below by connecting the hydraulic to joint between the 1st and 2nd road peace. (common method that doesn't work well)

[Koitenshin]

It might not work well in Poly Bridge, but it is a common design in the world for hydraulic bridges like this.

[bolt986]

This is an example of what I see very often (random gif from gallery)
https://gallery.drycactus.com/view/solution/2-2/drawbridge/301069

Here is another almost identical design that works much better because the hydraulic is attached at a better place making the bridge take much less stress from the motion.
https://gallery.drycactus.com/view/solution/2-2/drawbridge/300671

[Koitenshin]

The 2nd GIF illustrates the problem perfectly. The game doesn't treat both sides as they would operate in the real world. In the real world both sides work in parallel sync instead of lifting one side then the other.

[Dry Cactus]

Hydraulics do activate at exactly the same time and operate at the same speed, however in the 2nd GIF you will notice that the right-hand side of the bridge is supporting 4 road pieces, while the left is supporting only 3.
If you have a perfectly symmetrical bridge the hydraulics should operate identically on either side.

The fact that sometimes you're seeing a breakage is due to a known issue with the physics engine which regrettably we have no control over, in certain situations the simulation can diverge and have a different outcome.

Also because we chose to favor a slightly more "playful" physics approach, we have a certain amount of flexibility on each joint, so as bolt986 suggested if you have significant load on a hydraulic piston it can create lots of jitter, which prevents the joints from merging exactly at the position they were split in, which can cause further issues with vehicles crossing after the drawbridge has closed.

[Koitenshin]

It might be due to the physics engine, because the bridge is perfectly symmetrical (grid on, and paid careful attention to angle and length of pieces)

I'm seeing one side of the bridge raise first, then the other.
Sometimes the bridge fails for no reason whatsoever.
I can never run the simulation at 200% (the physics go completely haywire)
Sometimes the simulation will fail, then pass upon rerunning it.
etc.

[Dry Cactus]

Could I see a GIF of the bridge in question?
Or better yet a screenshot so I can re-create the same design and investigate further, because what you're describing sounds on the 'extreme' end of the scale of what should be tolerable physics deviation.

[Koitenshin]

I can't recreate the exact bridge, and completed levels aren't saved.
It was the overpass level (1-8) and (1-9) where the physics engine was really giving me trouble and messing up a lot.

[Dry Cactus]

Ok, will look into it.
Completed levels are automatically saved, to be found in the 'Load' panel with the name 'Auto-save Slot'.

[Koitenshin]

Due to the wonky physics I was able to make an amusing jelly like bridge for the first double decker level.

A simple box shaped structure of hexagons let the bridge wiggle to alleviate pressure.