How can I create and load models with additional information?

Question

I want to create game similar to original DOOM in Unity (using 2017.2). I'd like to make it possible to load entire levels from file, but I don't really want to write my own level editor that would serialize and deserialize Unity objects.

I'd like to allow the player base to create new levels using blender, without them needing to use Unity: all the logic and shapes should come from that single blender file.

I'm wondering how it could be possible to create levels in blender with some additional data, that could be processed from the Unity game. Just simple markers, for example stepping on platform A will open door B.

Answer 1

This is not going to be as easy as you think it would be, because only the Unity Editor can load Blender files. When you import a Blender file, it is converted to Unity's internal format. This is the only format which the actual game engine can read. The built game does not include any Editor-specific program code, including the code which imports assets from 3rd party formats. That means when you want to allow the built game to read .blend files at runtime, you need to include your own parser for the .blend file format. And if you go that far, then you can just load any meta-data from the Blender file you want, for example in form of a text datablock created with the text editor.

But note that there are games which built thriving modding communities of people who use the Unity Personal Edition to create asset bundles which the base game can then load as mods. Kerbal Space Program, for example. This makes modding a lot easier than using Blender, because you can release a pack of handy editor scripts and other assets which help your modders to perform common tasks.

Another positive aspect of using Unity is that the full power of the Unity scripting system is at their disposal for adding new game features. But that does of course also give great potential for abuse.

Answer 2

Well, I don't think blender can do logic, but it can do animating. You can animate a door opening and making it an animation in Unity as well. You can add a Collider and enabling the Trigger in front of the door to make it open. Making a map in blender isn't really efficient but it works. Just add a Mesh Collider to it without checking 'Convex' and it should automatically add colliders to it according to its shape.

The thing is, I'd like to put all the level logic and shape in one file.

Thats what scenes are for.