X7123M3-256

No, RCT2 only supports square maps. What you can do is increase the map size, then use black tiles to hide the parts you don't want. You can copy and paste individual scenery items with the tile inspector, but you cannot copy and paste a selection. A workaround is to build a tracked ride around the scenery you want to copy, and then use "save track design with scenery". You can then place the design where you want the scenery, and delete the ride.

The twister track does have that piece in OpenRCT2 - in fact, the twister coaster has every piece that's available on the vertical drop coaster and vice-versa. The only difference is the default support type (vertical drop track has square supports and twister supports are round). Unless you particularly care about this, or you require compatibility with vanilla, there is never a need to merge twister track with vertical drop track in OpenRCT2 - they have the same pieces and identical sprites.

You haven't said anything except what you think the file extension should be, which isn't really very important. Also, .OBJ is not a good choice because there is already a popular file format for 3D models with that extension, and this could create confusion. I think the assets should be ordinary PNG files placed in an archive together with the JSON, but I don't know what the OpenRCT2 team has planned.

Just set the launch speed so the train rolls back. You can't make the reverse launch actually work (not easily, anyway), but you don't actually need it for the train to make the circuit. The drop alone will take it through the loop and as long as the rear car makes it up to the station (which it will) the whole train gets pulled in. I usually add brake pieces set to the minimum speed and one upward piece at the end of the track, to ensure it doesn't go off the end when loaded. You could make the upward track invisible and add a few invisible cars to the front of the train if you don't like this.

It's a port of RCT2, not RCT1. The only RCT1 feature that was added back in was the booster pieces, as far as I'm aware - it doesn't have the RCT1 assets and the scenarios are remakes made for RCT2, not the original RCT1 scenarios. OpenRCT2 should be able to run using RCTC assets instead of vanilla RCT2. However, as far as I'm aware, it cannot yet load the scenario files. IIRC, RCTC is implemented in C. OpenRCT2 was originally written in C but is now mostly C++. Vanilla RCT2 and RCT1 were written in x86 assembly (MASM). I am not aware of any trainers for RCTC, but it does have the facility to convert savegames to/from the SV6 format, so that they can be edited with OpenRCT2 or vanilla RCT2. RCTC should be able to load hacked save games correctly so long as they work in vanilla (also, OpenRCT2 boosters and RCTC boosters are compatible. Other OpenRCT2-specific features won't work in Classic).

That one should not have any content missing (though I'm not going to go through and verify the presence of every object). I'm pretty sure it contains everything the full game does.

It depends which demo you're using. There's one that's missing content and there's another one that isn't.

The Arrow launched loop can be built in vanilla without any hacks at all - the reverse launch is not actually necessary for the train to make the loop (in game I mean, not IRL).

On Windows it's Documents/OpenRCT2. On Linux it's ~/.config/OpenRCT2. If there is not a subdirectory named object, just create it.

This still is the case. But this only works if the save file includes the scenery objects with it. Make sure you have "export plug-in objects with saved games" checked in the options. If you have a save file which is not exported, the game will show you a list of the objects that are missing but you'll have to locate and download them manually. You have to put them in the OpenRCT2/object folder, not the ObjData folder. This is a recent change.

If the element doesn't exist on the original ride it just appears invisible, which is fine if you were going to hide it anyway - although you'd need another cheat for that. To be honest, allowing some cheats but not others seems a bit arbitrary to me.

Prohibiting merging but allowing ZC is completely pointless, then you could just make the track segment where you would put the merge invisible and ZC track over the top instead. It looks exactly the same but it's not a merge.

They go in your OpenRCT2/object folder, but they'll still work if installed in ObjData.

If you aren't using the car ride anywhere else you're still taking an object slot (but it's a ride object not a scenery object). You're also using a ride slot for every car you place, and several more map data slots than a scenery item would take. The only thing you save is a single scenery slot (although technically you could put the car object sprite into a large scenery object that you're already using so it doesn't take any extra slots. This is a bit bothersome though.).

If you actually want a real ride vehicle, that's the way you do it. But for cars, I think most people would use scenery objects unless you want them to move.

Small scenery objects have a number of flags that dictate which parts of the tile they occupy. An object can be full tile, quarter tile, half tile, 3/4 tile, or diagonal (which means it occupies two diagonally opposing quadrants of the tile). Any full tile object will be counted as cover - it does not have to be a roof (I don't think the game makes a distinction between roofs and other scenery), and there doesn't seem to be a requirement for any walls either. If there exists a full tile object above the ride track, that tile is considered to be covered. Large scenery objects don't have these flags and cannot occupy less than a full tile.

I had some appear by accident once but I don't know what I did to create them. I think it was probably the result of a bug.

They've worked in all situations for me too. The other kind of corrupt element is mostly for vanilla compatibility - there is rarely a reason to prefer it and pretty much never a case where you'd need it. The "rides set type" command does exactly the same thing as the arbitrary ride types cheat. It used to be quicker, when you had to select the ride type through a spinner, but now that there's a dropdown I no longer use it.

There is in the source code. But I think most people do it by trial and error. I had a brief look at the source but going through by hand and calculating the length would take far longer than running the ride on fast forward to see if the trains get out of sync. It's a tedious process whichever way you do it - I thought about adding a console command to show track length but I never did.

Because the wild mouse treats that piece as a spinning control toggle. This should be a special case; the wild mouse is the only track on which boosters will not work, because there are no boosters. As soon as you switch the track style to wild mouse, every booster piece turns into a spinning control toggle piece. As for the reason why it's not reaching full speed, I don't think this is to do with the train but the track style. I think the booster acceleration is different on different tracks, but someone else would have to confirm as I've not looked at it in too much depth. If you put a longer section of booster it should reach the specified speed.

Both of those work for me. That's probably due to the trains having differing mass.

Exactly this. It is. That's why I'm not recommending that you do it, just pointing out that it's possible. It's a real pain to get right - the two parts of the train must cover exactly the same distance during a circuit, or they get out of sync and the ride stops working. There's a tutorial here. This also a more complicated hack; OpenRCT2 does not have a cheat to do it, so you'll have to use a debugger, hex editor, or similar tool to accomplish this

It does not have booster sprites. That's a spinning control toggle. The booster piece is actually the same track piece as the spinning control toggle, the game just changes the behaviour based on the track type. On wild mouse track, it functions as a spinning control toggle, and on everything else it behaves as a booster. This had to be done because it is impossible to add a new track piece to the game without a new save format, so they had to repurpose an existing one that most track types don't use. What do you mean "coded to work with boosters"? Object files don't contain code. Can you give an example of a train that doesn't work?

No you don't. You are making the track invisible anyway, so there's no reason to merge (if you use a track piece that is not supported on a given track style, it still works but the missing piece will not be drawn). In any case, the steel wild mouse track has all the same track pieces as the wooden wild mouse and does allow brakes, so I would recommend using that instead. You can always switch the track type back again after you've built the brakes (you can do the same for diagonals, or really any track piece you want - you only need to merge if the track is supposed to be visible). Unfortunately not. You can get this effect using a shoestring, but a shoestring is very complicated to set up and IMO not really worth it for something so simple. Another option is to put brakes just after the turn, then add a few invisible cars in front of the rafts so that the brakes are hit during the turn. Of course, you then have to account for this delay everywhere else you used brakes. It's also not an easy hack to set up - unlike a shoestring this can't be done with cheats, and is less flexible but it requires a lot less trial and error. This is called breaking out. Thing is, there are no eddies on your river left channel so there is no place to break out - once over the lip, the rafts aren't stopping until they wash out at the bottom. I would have the rafts follow the flow of the river, as they do now, but place brakes where the hydraulics would form, because these would slow the raft IRL. I'd have it drop over the first ledge and then slow down to ~15mph in the pool at the bottom. Ideally you would brake slightly in the turn before the slide, but as noted above that's not easy to do so I'd skip it and just put brakes at the bottom of the slide. Then more brakes once they turn out of the flow. The main thing is to not have the rafts going really fast on flat water.

It's forced perspective - the track is not connected but the two ends are lined up so that they look connected from that angle. The ride is non-functional - I did build one that was functional, but I couldn't get it to work consistently. The synchronization has to be perfect for the illusion to still work with a train running.