A communication device for handling an open direct discovery comprises a storage unit for storing instructions and a processing means coupled to the storage unit. As the gear turns in one direction, the cam plates are pulled toward one another in a guided straight line until they engage and lock around the gear. For each sampling path the rendering unit is configured to determine the color or grayscale value for the corresponding pixel based on the determined image data values for the plurality of sampled points for the path. The method may also include receiving optimization metrics and constraints for the dataset of materials.