Importing 'prefabs' objects in a scene

[Mike]

I'm trying to import a 'prefab' xml object in a scene using lua scripting.

From the ninja snow war example, it seems that this is achieved using the InstantiateXML function from angelscript API, but I haven't found an equivalent function in the lua API.

[Lasse Öörni]

You'll find that the Lua API is not 100%, typically "difficult" things that have to do with file access or object allocation via shared pointers are not all there.

I added Instantiate & InstantiateXML in a recent commit. There's an example in the commit message.

[Mike]

Awesome! Works perfectly.

[Mike]

Now I have trouble getting the physics from the prefab to work.

[Lasse Öörni]

Do you have a PhysicsWorld component in your scene root node? I didn't have trouble making eg. the ninja prefab behave physically when I instantiated it into the Physics Lua sample scene.

[Mike]

Sorry for this one, I forgot to update my resource path in the editor, now everything works as expected.

[Mike]

Just tested on Android (with luaJIT enabled). Unfortunately it doesn't work for now.

[Chris Friesen]

If you changed the resource paths via command line execution you will have to add them to CommandLine.txt

[Chris Friesen]

IOS & Android read from that file since you can't read program arguments.

[Mike]

Thanks for tips Chris.

I'm already using default resource path for the assets to instantiate.
I think the issue comes from using fileSystem:GetProgramDir() instead of cache:GetResource.
I've tried to use cache:GetResource previously but it failed (tested on desktop).

[Lasse Öörni]

On Android & iOS there's a slight hack for accessing the resources bundled with the application, and it doesn't make sense to try to add extra resource directories. On these systems FileSystem::GetProgramDir() returns the directory for accessing them. Normally the CoreData & Data directories would be copied as resources.

[Mike]

So is it possible in some way to use resources cache instead of Filesystem to access the objects with the InstantiateXML function?

[Lasse Öörni]

In C++ and AngelScript certainly, as you can call ResourceCache::GetFile() which does the lookup for you and returns a file. In Lua this likely isn't possible currently.

However note that there's nothing magical in what ResourceCache is doing; opening a file with a path constructed like GetProgramDir() + "Data/YourResourceName" should access files just fine on iOS and Android too. The "magic" to access resources from within an apk is in the File class.

[Mike]

OK, thanks, will try to figure out what's going on.