A virtual model placement system can generate virtual floors and virtual walls to correspond to a real-world environment. Virtual items such as doors, windows, lamps, can be placed on the generated virtual walls and the system can generate dynamic updates of the placed items in response to movement by a user's device (e.g., a smartphone moving from right to left). The virtual items can be initially placed as primitives and then rendered to new positions upon the user selecting a render or lock instruction.