Techniques of tracking a hand controller in a VR system involves detecting, by photodiodes in the hand controller, patterns of diffuse radiation generated by diffuse LEDs in the HMD. Such techniques can also include comparing the detected patterns to those simulated offline previously and represented in a lookup table (LUT). By looking up the detected patterns in the LUT, the VR system may determine the position and/or orientation of the hand controller with sub-millimeter accuracy. Some advantages of the improved techniques can be in the simplicity and/or low cost of the components without sacrificing accuracy in deriving the position and orientation of the hand controller.