All the engine source code is available in the distributed package. A couple of third-party libraries are pre-compiled, but they're open-sourced (MIT license) with sources hosted on GitHub.
While Naninovel is focused around traditional visual novel games the engine is designed to allow integration with existing projects. If you're making a 3D adventure game, RPG or game of any other genre — you can still use Naninovel as a drop-in dialogue system.
Be aware, that in most cases such integration will require C# scripting (or visual scripting) in varying extent. See the engine architecture overview to get a grasp of how Naninovel works and integration guide for more information on the integration options
Sure, you can freely "inject" any custom logic to the default Naninovel flow. In most cases, however, this will require using the engine's C# API (via either writing custom C# scripts or using a visual scripting solution). Check the engine services guide for the list of available open APIs, which allows interaction with the engine; you may also make use of state outsourcing, custom actor implementations and custom commands in the process.
Naninovel can work with any language, but to display text in some languages, you'll need a compatible font. Google's Roboto is used by default, which supports all Latin, Cyrillic, and Greek characters in Unicode 7.0. You can change the font used in any of the built-in UIs with UI customization feature; for the printed text messages, create custom printers and set the desired font.
In case you're aiming to support as much languages, as possible, check out Noto fonts.
For the UI part (changing/adding buttons or panel layout and style) use the UI customization feature; for everything else set
Title Script at the scripts configuration menu (Naninovel -> Configuration -> Scripts) and use script commands to setup the scene just like when writing a scenario. The title script will be automatically played when entering the title menu.
Skybox Material in
Window -> Rendering -> Lighting Settings editor menu.
When you remove the skybox, camera's background color will be used instead to fill the screen when no objects are visible. You can change that color (as well as other related settings) by creating a camera prefab and assigning it to
Custom Camera Prefab property found inside
Naninovel -> Configuration -> Camera menu.
Reference Resolution at the camera configuration menu (Naninovel -> Configuration -> Camera) equal to the backgrounds resolution. Also, make sure the background textures are imported with the correct settings (eg,
Max Size is high enough).
For standalone (PC, Mac, Linux) builds you can select the available aspect ratios in the player settings; for web, consoles and mobiles you can't force a specific aspect ratio and have to adapt for the target devices instead.
Given the source textures (background sprites) of a specific resolution, the only options to "adapt" them for a different aspect ratio are: resize (will distort the image), add black bars or crop. The least noticeable option is to crop, obviously. Naninovel will automatically do the cropping, when
Auto Correct Ortho Size is enabled in the camera configuration menu and display aspect ratio is different from the
Reference Resolution aspect set in the same configuration menu. The auto correction will ensure, that the user won't see any black bars or distortions, no matter which display or device is used to run the game.
To manually handle the aspect ratio differences (eg, if you prefer to add black bars or resize the images instead of cropping), disable
Auto Correct Ortho Size option in the camera configuration menu. You can then control orthographic size of the camera used by Naninovel with
CameraManager engine service.
Use custom commands.