Abstract: Learning-based 3D property extraction can include: capturing a series of live 2D images of a participatory event including at least a portion of at least one reference visual feature of the participatory event and at least a portion of at least one object involved in the participatory event; and training a neural network to recognize at least one 3D property pertaining to the object in response to the live 2D images based on a set of timestamped 2D training images and 3D measurements of the object obtained during at least one prior training event for the neural network.