Function build_scene_from_refs 

pub fn build_scene_from_refs<'a, I>(
    children: I,
    viewport: (f32, f32),
    root_css: CssStyle,
    anim: Option<BuildAnimationCtx>,
) -> BuiltScene<'a>
where
    I: IntoIterator<Item = &'a ChildComponent>,

Same as build_scene_with_root but accepts an iterator over &ChildComponent references. Useful when the caller has filtered or re-ordered the scene’s children and doesn’t want to clone.