A computing system and method to generate an avatar wearing a piece of clothing. Given a generic clothing model acquired for the avatar, the system generates a customized clothing model based on uniformly scaling the generic clothing model according to a size of the avatar, identifies one or more edges or boundaries of the clothing, deforms a clothing mesh of the scaled clothing model at the one or more edges by stretching and/or shrinking the edges, and performs a physical simulation of fitting the deformed clothing model on the avatar to generate a fitted clothing model for the avatar. User interfaces can be optionally provided to interactively adjust the scaling, deforming, and/or physical simulation of the clothing models.