Class Scene

pvtrace/scene/scene.py:17–125

A scene graph of nodes.

class Scene(object):
    """ A scene graph of nodes.
    """

    def __init__(self, root=None):
        super(Scene, self).__init__()
        self.root = root

    def finalise_nodes(self):
        """ Update bounding boxes of node hierarchy in prepration for tracing.
        """
        root = self.root
        if root is not None:

            # Clear any existing bounding boxes
            for node in PostOrderIter(root):
                node.bounding_box = None

            # More efficiency to calcualte from leaves to root because because
            # the parent's bounding box calculation requires the size of the
            # child's bounding box.
            leaves = self.root.leaves
            for leaf_node in leaves:
                node = leaf_node
                while True:
                    _ = node.bounding_box  # will force recalculation
                    node = node.parent
                    if node is None:
                        break

    @property
    def light_nodes(self) -> Sequence[Light]:
        """ Returns all lights in the scene.
        """
        root = self.root
        found_nodes = []
        for node in LevelOrderIter(root):
            if isinstance(node.light, Light):
                found_nodes.append(node)
        return found_nodes

    @property
    def component_nodes(self) -> Sequence[Component]:
        """ Returns all lights in the scene.
        """
        root = self.root
        found_nodes = []
        for node in LevelOrderIter(root):
            if node.geometry:
                if node.geometry.material:
                    found_nodes.extend(node.geometry.material.components)
        return found_nodes

    def emit(self, num_rays):
        """ Rays are emitted in the coordinate system of the world node.
        
            Internally the scene cycles through Light nodes, askes them to emit
            a ray and the converts the ray to the world coordinate system.