CrAM: artist-friendly crowds on "Edge of Tomorrow"

classroom use is granted without fee provided that copies are not made or distributed for commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the Owner/Author. Managing crowds is traditionally a very technical task, with a high barrier to entry for creative artists. Over the past few years, we have built a toolkit called CrAM (Crowd Asset Manager) that allows crowds to be an integral part of Layout and Animation, for composition, creative control and very fast turnaround of shot changes. Recent projects like Edge of Tomorrow have truly taken advantage of the system on an unprecedented scale. In cel animation, one technique used to mitigate cost was the re-use of animated cels. This allowed animators to fill out larger scenes with previously animated snippets, but was limited by factors like perspective and lighting changes. By relying on 3d point animation caches, the CrAM system applies the same mindset to the 3d world by providing a simple way for layout/animation teams to create complex scenes and re-use animation with maximum efficiency. CrAM Assets can be thought of as a character performing a canned action, such as running, falling or shooting: these elements are created by animators using the standard character animation pipeline and produce lighting-compatible geometry caches. Assets can be grouped into assemblies for coordinated interactions, and are typically organized by environment location or by sequence/story point, on top of which artists can use tags to further organize the assets. Artists are presented with a palette of available actions that can quickly be searched or previewed. Adding assets to their scene is as simple as clicking where they want it, but they can also draw paths on terrain to quickly lay out or orient their characters: when the artist draws a stroke, points from the screen-space location are projected onto the geometry plane as a NURBs curve. Python callbacks then fire and, if spawning new assets, select an asset at random from a highlighted list and create new instances spaced along the projected curve (regularly or randomly). Other functions allow artists to reposition, orient or clone assets using the drawing/curve paradigm for placement. If placing on a non-planar surface, an optional collision surface can be specified that instances can be mapped to along the Y-axis. Assets can be …