1. A method of three-dimensional comparative visualization of a building comprising glass components, comprising, by a computer system: causing a building model for a modeled building to be presented on a client computer, the building model comprising a three-dimensional scene of at least one of an interior and an exterior of the modeled building; wherein the three-dimensional scene comprises an individual rendering of a photorealistic appearance of at least selected glass products for the modeled building in accordance with configured modeling properties, the three-dimensional scene comprising photorealistic views through the at least selected glass products; wherein the configured modeling properties comprise a set of modeling properties for each glass product of a set of glass products, the set of glass products comprising the at least selected glass products and one or more alternative glass products distinct from the at least selected glass products, the set of modeling properties reflecting at least selected attributes of the glass product related to at least one of color, hue, brightness and transparency of the glass product; wherein, for each glass product of the at least selected glass products, the set of modeling properties indicates: how the glass product should photorealistically appear given the at least selected attributes of the glass products and one or more stored building-site attributes, wherein the one or more stored building-site attributes are related to at least one of sunlight direction and sunlight brightness at a geographic site of the modeled building and indicate an orientation of the modeled building relative to at least one sunlight obstruction; and how the photorealistic appearance of the glass product should differ in response to changes to a set of user-selectable modeling variables that vary at least one of weather, a time of day and a time of year; receiving a user change to the three-dimensional scene via a graphical user interface (GUI) component, wherein the user change comprises an exchange of a particular glass product of the at least selected glass products for an alternative glass product of the one or more alternative glass products, wherein the at least one of color, hue, brightness and transparency of the alternative glass product is different from the at least one of color, hue, brightness and transparency of the particular glass product; accessing the configured modeling properties responsive to the user change; and dynamically changing the building model in accordance with the user change, the dynamically changing comprising: individually rendering a photorealistic appearance of the alternative glass product in place of the particular glass product in accordance with the set of modeling properties of the alternative glass product; and adjusting lighting in the three-dimensional scene based, at least in part, on the at least one of color, hue, brightness and transparency of the alternative glass product and the at least one of sunlight direction and sunlight brightness indicated in the building-site attributes, wherein the three-dimensional scene as adjusted includes a photorealistic view through the alternative glass product.