Function resolve_basic_material

pub fn resolve_basic_material<'a, I>(node_then_ancestors: I) -> BasicMaterial
where
    I: IntoIterator<Item = &'a NodePresentation>,

Colour and opacity for a node, from the node and its ancestors given nearest first. The nearest diffuseColor wins, and opacity comes from that same node (default 1); an opacity on a node without diffuseColor is not used. Used for curves, and for meshes without a glTF material.