.. _scene_structure:

Scene structure
===============

In the original game, the scene layed out similar to a tree.  Each object can have multiple children
which will move according to their parent.  Every object is an instance of a class derived from
`zCVob` (See :ref:`object-kinds`) and thus have their own behavior.  Since REGoth is building upon
bs::framework, which allows for using an Entity-Component-System as well as the traditional object
oriented way Gothic is using, we have to decide which way we go.

As far as I understand, using bs::framework as object-oriented framework will just create objects
with a single component internally.  I don't see any reason to not go for the component based
approach.


Logic
-----

Traditionally, the logic of an object in Gothic was given by the type of class it was instantiated
of.  I would suggest keeping all behavior of an object inside *Logic-Components*. There will be
very few kinds to take into account from the original game:

* Characters
* Interactable objects
* Triggers
* Items on the ground

Of course these could (and should) be split into multiple components.  For example, the
*Character*-Component could manage the appearance, animations and inventory of a character, while
other components could do AI or handle being controlled by the Player.


Visuals
-------

Since the way rendering works is a little bit different from Gothic, we have to come up with a
solution to get Gothic's visuals attached to the objects.  In bs::framework, there is a
*Renderable*-Component, which holds mesh data, materials, etc.  For REGoth, I would suggest wrapping
that *Renderable*-component into a *Visual*-Component, which is able to load and digest the original
data.  It could then save everything needed to display an object as a child-object to keep other
components from directly interacting with what the *Visual*-Component needed to create.

To match the original game, we would need at least the following visuals:

* Static meshes (.3DS)
* Skeletal-Meshes (.ASC)
* Morph-Meshes
* Particle-Effects