Object Tracking

overview object tracking is a feature of ncam reality that allows the system to track specific markers when they are detected in either the camera bar or the main camera feed the position of the marker can then be streamed into unreal engine 4 as part of the ncam livelink data mk2 only object tracking is only available on the mk2 platform ncam settings object tracking is activated via the preferences window of the full ui the settings can be found on the lower part of the tracking tab enable the " track independent markers " checkbox to turn on object tracking the settings below have the following effects video source defines whether the pattern should be detected in the camera bar feed or the main camera feed coordinate system defines how the pattern is tracked in 3d space "world from marker" is typically used marker side this tells the system the size of the pattern that is being used ensure that this matches exactly the size of the object tracking pattern that is being used see the charts docid\ ukr iwplppl9zrfa3nybm section for information on the object tracking patterns available unreal settings configure unreal engine as per normal, ensure the " markers " field is selected as part of the ncam profile however following this, "ncam markers" should appear in the livelink list of data sources to attach the marker livelink data to an object in the ue4 scene simply select an actor and attach a "livelink controller" component to it inside the details panel of the livelink component, set the " subject representation " to " ncammarkers " below this a "marker info" area is shown, enter into this the id of the marker being used, this is printed on the lower edge of the marker pattern the transform values below are used to apply local offsets to the position of the tracked object relative to the marker be aware that scaling here will override any scaling that is applied at an object level limitations there are a number of limitations to be aware of when working with object tracking livelink data can only be applied to a mesh and will not work when applied to null actors operationally this can be solved by parenting the actor you wish to track to a mesh actor that is scaled almost to zero patterns can only be tracked when they are visible to the camera, if the patterns are occluded or move out of the range of detection then the tracked object will hang in space at the last known position consider increasing/decreasing the size of the pattern to fit the type of shot