Various implementations disclosed herein include devices, systems, and methods that provide measurement techniques for electronic devices such as optical see-through head mounted devices. In some implementations, a line of sight technique is used to identify a 3D position of a measurement point to enable measurement of an object in a 3D environment. In some implementations, different measurement point identification techniques are automatically selected and used to identify a 3D position of a measurement point to enable measurement of an object in a 3D environment. In some implementations, a 3D position of a measurement point is identified to enable measurement of an object in a 3D environment, where the measurement point is identified by selecting from multiple candidates that are determined using different measurement point selection techniques.