Base node

Base node is a scene node that stores hierarchical information (a handle to the parent node and a set of handles to children nodes), local and global transform, name, tag, lifetime, etc. It has self-describing name - it is used as a base node for every other scene node (via composition).

It has no graphical information, so it is invisible all the time, but it is useful as a "container" for children nodes.

How to create

Use the PivotBuilder to create an instance of the Pivot node (remember Base node itself is used only to build other node types):

#![allow(unused)]
fn main() {
extern crate fyrox;
use fyrox::scene::{base::BaseBuilder, pivot::PivotBuilder, Scene};
fn build_node(scene: &mut Scene) {
let handle = PivotBuilder::new(BaseBuilder::new()).build(&mut scene.graph);
}
}

Building a complex hierarchy

To build a complex hierarchy of some nodes, use .with_children() method of the BaseBuilder, it allows you to build a hierarchy of any complexity:

#![allow(unused)]
fn main() {
extern crate fyrox;
use fyrox::scene::{base::BaseBuilder, pivot::PivotBuilder, camera::CameraBuilder, Scene};

fn build_node(scene: &mut Scene) {
let handle = PivotBuilder::new(BaseBuilder::new()
    .with_children(&[
        CameraBuilder::new(BaseBuilder::new()).build(&mut scene.graph),
        PivotBuilder::new(BaseBuilder::new()
            .with_children(&[PivotBuilder::new(BaseBuilder::new()).build(&mut scene.graph)]))
            .build(&mut scene.graph),
    ]))
    .build(&mut scene.graph);
}
}

Note that when we're building a Camera instance, we're passing a new instance of BaseBuilder to it, this instance can also be used to set some properties and a set of children nodes.

The "fluent syntax" is not mandatory to use, the above code snipped could be rewritten like this:

#![allow(unused)]
fn main() {
extern crate fyrox;
use fyrox::scene::{base::BaseBuilder, pivot::PivotBuilder, camera::CameraBuilder, Scene};

fn build_node(scene: &mut Scene) {
let camera = CameraBuilder::new(BaseBuilder::new()).build(&mut scene.graph);

let child_base = PivotBuilder::new(BaseBuilder::new()).build(&mut scene.graph);

let base = PivotBuilder::new(BaseBuilder::new()
    .with_children(&[child_base]))
    .build(&mut scene.graph);

let handle = PivotBuilder::new(BaseBuilder::new()
    .with_children(&[camera, base]))
    .build(&mut scene.graph);
}
}

However, it looks less informative, because it loses the hierarchical view and it is harder to tell the relations between objects.

Transform

Base node has a local transform that allows you to translate/scale/rotate/etc. your node as you want to. For example, to move a node at specific location you could use this:

#![allow(unused)]
fn main() {
extern crate fyrox;
use fyrox::{
   core::{algebra::Vector3, pool::Handle},
   scene::{node::Node, Scene},
};

fn translate_node(scene: &mut Scene, node_handle: Handle<Node>) {
scene.graph[node_handle]
    .local_transform_mut()
    .set_position(Vector3::new(1.0, 0.0, 2.0));
}
}

You could also chain multiple set_x calls, like so:

#![allow(unused)]
fn main() {
extern crate fyrox;
use fyrox::{
   core::{algebra::Vector3, pool::Handle},
   scene::{node::Node, Scene},
};

fn transform_node(scene: &mut Scene, node_handle: Handle<Node>) {
scene.graph[node_handle]
    .local_transform_mut()
    .set_position(Vector3::new(1.0, 0.0, 2.0))
    .set_scale(Vector3::new(2.0, 2.0, 2.0))
    .set_rotation_offset(Vector3::new(1.0, 1.0, 0.0));
}
}