Unity -> Xenko, confused about script inheritance and other

#1

Hi all,

I have started developping a Tower Defense game in Unity a month ago. I have been amazed with the flexibility and features Xenko offers at such an early stage and have decided to port my existing code to use Xenko. I have some questions:

  1. All towers in my game inherit from a base class Tower that is a Monobehaviour (equivalent of Component in Xenko). I then derive Canon, Turret etc… Then when I do raycasting to select a tower for example, all I do is a raycastedObject.GetComponent<Tower>(), if that returns a reference, it means it is a concrete Tower or a derived class (Canon, Turret …). Does the Get<>() work the same way in Xenko?

  2. My game is tile based, and builds a level from a file in a grid format. I instantiate the tiles from prefab and put them in their right position. In Unity I had a problem with too many draw calls (400 with just the level tiles which is a lot for a mobile game). Is there a way to have “prefab instances” that get drawn together ?

Those are all my questions for now. Thank you for your help!!

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#2

Hi,

I believe than answer to your first question is “yes”. I have not tested it myself though. Looking at the engine source and the documentation. An entity stores it’s components in a EntityComponentCollection. According to the documentation EntityComponentCollection.Get<>() “Gets the first component of the specified type or derived type” and returns “The first component or null if it was not found”.

No idea about your second question though.

#3

Oh, how did I miss that! That’s perfect for my needs. Thank you :slight_smile:

#4

You’re welcome.

I also just thought about your second question. If you plan on using SpriteComponents for your tiles. The SpriteComponent renderer does use a Sprite3DBatch to render them. So there could possibly be some batching, depending on what options you use and if they share textures etc.

#5

Actually I am using 3d boxes as tiles in my games so definitely not using Sprites. In Unity I share the material accross my instantiated prefabs and use StaticBatchingUtility class to batch them together (although sometimes it does not seem to work and still incurs >1 draw call per tile which is a lot). Maybe it will come in handy if I ever use sprites in the future.

#6

If your tiles are static (not changing at runtime), you can already create a Scene with many models, and compile it as a single Model using the “Prefab Model” asset (release notes: https://doc.xenko.com/1.8/ReleaseNotes.html#prefab-model)

However, it doesn’t help for dynamic cases (tiles changing as you play), where actual GPU instancing is needed. We’ll work on it at some point though!

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