A system comprising: a source of electromagnetic radiation configured to emit electromagnetic radiation into an area; a sensing device configured to: receive, at a plurality of times, the electromagnetic radiation after being reflected from a retro-reflective material of an article positioned in the area; wherein the retro-reflective material is one of a plurality of different types of retro-reflective materials having different characteristics; and generate data based on the received reflected electromagnetic radiation; and a controller configured to: process the data generated by the sensing device to determine, for each of the plurality of times, a corresponding position of the article; identify, based on the plurality of positions of the article, a path through which the article has moved within the area; determine whether the path correlates to a stored path of a plurality of stored paths representing pre-defined gestures, comprising identifying the characteristic of the retro-reflective material, and applying a tolerance level, of a plurality of tolerance levels, with respect to determining correspondence between the path and the stored path, based on the characteristic identified, wherein each retro-reflective material of the plurality of different types of retro-reflective materials has a corresponding tolerance level; and output a control signal to actuate a corresponding effect in response to determining that the path correlates to the stored path of the plurality of stored paths representing pre-defined gestures. a source of electromagnetic radiation configured to emit electromagnetic radiation into an area; a sensing device configured to: receive, at a plurality of times, the electromagnetic radiation after being reflected from a retro-reflective material of an article positioned in the area; wherein the retro-reflective material is one of a plurality of different types of retro-reflective materials having different characteristics; and generate data based on the received reflected electromagnetic radiation; and receive, at a plurality of times, the electromagnetic radiation after being reflected from a retro-reflective material of an article positioned in the area; wherein the retro-reflective material is one of a plurality of different types of retro-reflective materials having different characteristics; and generate data based on the received reflected electromagnetic radiation; and a controller configured to: process the data generated by the sensing device to determine, for each of the plurality of times, a corresponding position of the article; identify, based on the plurality of positions of the article, a path through which the article has moved within the area; determine whether the path correlates to a stored path of a plurality of stored paths representing pre-defined gestures, comprising identifying the characteristic of the retro-reflective material, and applying a tolerance level, of a plurality of tolerance levels, with respect to determining correspondence between the path and the stored path, based on the characteristic identified, wherein each retro-reflective material of the plurality of different types of retro-reflective materials has a corresponding tolerance level; and output a control signal to actuate a corresponding effect in response to determining that the path correlates to the stored path of the plurality of stored paths representing pre-defined gestures. identify, based on the plurality of positions of the article, a path through which the article has moved within the area; determine whether the path correlates to a stored path of a plurality of stored paths representing pre-defined gestures, comprising identifying the characteristic of the retro-reflective material, and applying a tolerance level, of a plurality of tolerance levels, with respect to determining correspondence between the path and the stored path, based on the characteristic identified, wherein each retro-reflective material of the plurality of different types of retro-reflective materials has a corresponding tolerance level; and output a control signal to actuate a corresponding effect in response to determining that the path correlates to the stored path of the plurality of stored paths representing pre-defined gestures.