A method for dynamically selecting and presenting an occluder in a mixed-reality environment based on assumptions of a user's body in the mixed-reality environment, the method comprising: identifying a relative position of a physical device in a mixed-reality environment, the physical device is being worn or held by a user, relative movements and positioning of the physical device are tracked in the mixed-reality environment based on one or more sensor outputs; determining an assumed understanding of a user's body within the mixed-reality environment based at least in part on the identified relative position of the physical device in the mixed-reality environment and without relying on camera imaging of the user's body, the assumed understanding of the user's body including at least an assumed position of the user's body; the method being characterized by: identifying a set of occluders that are available for selection for presentation within the mixed-reality environment and that correspond with the assumed position of the user's body; selecting a particular occluder from the set of occluders, the selection of the particular occluder being based on the assumed understanding of the user's body within the mixed-reality environment and by selecting the particular occluder that is determined to have a higher percentage of correspondence to the assumed position of the user's body than other occluders in the set of occluders; and modifying the presentation of the mixed-reality environment by positioning the occluder in the mixed-reality environment with a particular size and position corresponding with the assumed understanding of the user's body. identifying a relative position of a physical device in a mixed-reality environment, the physical device is being worn or held by a user, relative movements and positioning of the physical device are tracked in the mixed-reality environment based on one or more sensor outputs; determining an assumed understanding of a user's body within the mixed-reality environment based at least in part on the identified relative position of the physical device in the mixed-reality environment and without relying on camera imaging of the user's body, the assumed understanding of the user's body including at least an assumed position of the user's body; the method being characterized by: identifying a set of occluders that are available for selection for presentation within the mixed-reality environment and that correspond with the assumed position of the user's body; selecting a particular occluder from the set of occluders, the selection of the particular occluder being based on the assumed understanding of the user's body within the mixed-reality environment and by selecting the particular occluder that is determined to have a higher percentage of correspondence to the assumed position of the user's body than other occluders in the set of occluders; and modifying the presentation of the mixed-reality environment by positioning the occluder in the mixed-reality environment with a particular size and position corresponding with the assumed understanding of the user's body. identifying a set of occluders that are available for selection for presentation within the mixed-reality environment and that correspond with the assumed position of the user's body; selecting a particular occluder from the set of occluders, the selection of the particular occluder being based on the assumed understanding of the user's body within the mixed-reality environment and by selecting the particular occluder that is determined to have a higher percentage of correspondence to the assumed position of the user's body than other occluders in the set of occluders; and modifying the presentation of the mixed-reality environment by positioning the occluder in the mixed-reality environment with a particular size and position corresponding with the assumed understanding of the user's body.