OMSI 2 Mods in openOMSI: Which Buses, Maps and Add-ons Already Work?

Do OMSI 2 mods work with openOMSI?

The basic goal is: Yes. openOMSI is designed to read and run existing content from OMSI 2 directly. This includes maps, buses, scenery objects, splines, scripts, timetables, HOF files, fonts, sounds, weather data, ticket systems, plugins and other content from the OMSI world.

But the crucial point is the word goal. openOMSI is still in an early stage of development. Although the project aims for the most comprehensive compatibility possible, features may still be missing, faulty or change between versions. A mod may already load and basically work today without every single function working exactly as it does in classic OMSI 2.

Do OMSI mods have to be converted for openOMSI?

Ideally, no. That is one of the project's central approaches. openOMSI reads the known OMSI file formats directly and attempts to reproduce their behavior. Existing mods should therefore not first have to be converted into a new proprietary format.

This clearly distinguishes openOMSI from a completely new bus simulator. With a conventional successor, developers and modders would often have to decide whether old content needs to be re-exported, adapted or rebuilt from scratch. openOMSI, by contrast, attempts to retain the existing OMSI world as its foundation.

In practice, however, the following still applies: Just because a mod does not have to be converted, it is not automatically fully compatible. Complex content in particular may use functions that openOMSI does not yet reproduce exactly.

Which OMSI buses work with openOMSI?

Many buses can already be loaded and driven, but vehicles in particular are among the most complicated types of content. An OMSI bus consists not only of a 3D model and some textures, but of an entire collection of interconnected systems.

These include scripts, animations, doors, sounds, destination displays, IBIS, engine logic, transmission, lighting, triggers, variables and passenger functions. Even small differences in script interpretation can therefore result in a bus being visible and drivable while individual functions still do not work correctly.

Individual vehicles may still experience texture errors, certain functions may not respond correctly, or materials may be displayed differently from the original. Dynamic textures and special displays are also among the areas where differences may occur.

That is why a fixed list along the lines of “Bus X works, Bus Y does not” would quickly become outdated. For now, a classification is much more useful: The more conventional a vehicle is and the more closely it is built to normal OMSI standards, the greater the general chance that it already works to a large extent. Highly complex community buses with many custom solutions, on the other hand, may still be more likely to show problems.

Do OMSI maps work with openOMSI?

Maps should also generally be usable without conversion. To this end, openOMSI supports typical OMSI components such as tiles, splines, intersections, scenery objects, textures, AI traffic, timetables, HOF files, traffic lights and terrain.

Loading a map is only the first step, however. For it to behave truly identically to OMSI 2, all its components must work together correctly. That is precisely where differences may still occur at present.

One example is scenery objects whose texture changes during operation. Such functions may be used for bus stop signs, advertising surfaces or dynamic displays, for example. If openOMSI does not correctly interpret every custom solution here, a map may still load completely while individual details are displayed incorrectly.

This illustrates quite well why “map loads” and “map works completely” are two different statements. Roads, buildings and routes may appear correctly while individual objects, displays or special functions are not yet exactly right.

Can I continue using paid OMSI add-ons?

In principle, commercial OMSI content can also be used, provided you legally own the corresponding files and they already work technically with openOMSI.

openOMSI itself does not distribute paid add-ons and does not replace them. The project generally contains no original OMSI game content. It uses the files from your existing OMSI 2 installation.

So if you own a purchased bus or map add-on, its files remain necessary. openOMSI does not bypass any license and does not automatically include this content.

Nevertheless, a blanket statement such as “all payware DLCs work” would currently be incorrect. Commercial add-ons can also use complex scripts, their own plugins or special graphics systems. Actual compatibility therefore always depends on the specific add-on and the current state of development.

What about OMSI plugins?

Plugins are also part of openOMSI's compatibility goal. Both existing OMSI plugins and newer extension options play a role here. For classic OMSI plugins, a solution exists that allows older 32-bit extensions to continue being integrated.

openOMSI also provides options for Lua extensions. These can be used, among other things, to read and write variables, trigger events and process certain occurrences.

Even so, no one should assume here either that every old plugin already runs flawlessly. Plugins sometimes reach very deeply into OMSI and may depend heavily on precisely how the original works internally. Such special cases in particular are among the more difficult areas of a complete reproduction.

Why does a mod sometimes not work properly despite being compatible?

Because in openOMSI, “compatible” currently does not automatically mean “identical in every detail.”

A bus can load, be drivable and still have a faulty matrix. A map can appear complete while individual dynamic textures are displayed incorrectly. An add-on can start in principle while a special plugin or an unusual script solution causes problems.

That is precisely why one should distinguish between three levels: The content is recognized, the content basically works, and the content behaves completely as it does in OMSI 2. Depending on the mod, openOMSI already reaches different ones of these levels.

In the long term, the project aims to come as close as possible to OMSI 2.2.032. For players, however, the most important thing at present is to remain realistic: The existing collection does not have to be rebuilt from scratch, but it also does not automatically run completely error-free yet.

What does this mean for a large OMSI collection?

Anyone who has collected hundreds of buses, maps and add-ons over the years does not generally have to give up this content. That is one of the biggest differences from a completely new simulator. openOMSI is deliberately attempting to continue using this existing world.

For now, however, it is more worthwhile to test things step by step. Rather than immediately treating the entire collection as automatically compatible, it makes more sense to try out individual maps and vehicles first. This makes it possible to quickly identify whether all important functions already work correctly, especially with complex mods.

The new mod management also helps with this. Additional content can be integrated separately from the actual OMSI 2 installation without directly overwriting the original installation. This makes testing different content easier, but of course it does not resolve any technical incompatibilities.

openOMSI compatibility: The great goal is clear, but the path there is not yet complete

The basic idea behind openOMSI is unusually interesting for the OMSI community: no completely new content world, no hard break and, wherever possible, no obligation to rebuild ten-year-old mods. The familiar maps, buses and add-ons are intended to live on—just on a new technical foundation.

This already works in many areas. At the same time, work is still ongoing on vehicle functions, materials, dynamic textures, individual scripts and special mod solutions.

openOMSI is therefore currently neither a system in which all mods are guaranteed to work perfectly nor one in which old content is fundamentally unusable. It lies somewhere in between—and this area is currently shifting further with almost every new build.

Which map or bus have you already tested with openOMSI—and what already works for you, and what does not yet?