Aspects of the present disclosure are directed to providing an artificial reality environment with augments and surfaces. An “augment” is a virtual container in 3D space that can include presentation data, context, and logic. An artificial reality system can use augments as the fundamental building block for displaying 2D and 3D models in the artificial reality environment. For example, augments can represent people, places, and things in an artificial reality environment and can respond to a context such as a current display mode, time of day, a type of surface the augment is on, a relationship to other augments, etc. Augments can be on a “surface” that has a layout and properties that cause augments on that surface to display in different ways. Augments and other objects (real or virtual) can also interact, where these interactions can be controlled by rules for the objects evaluated based on information from the shell.