I'm trying to get an understanding of a fundamental function in AR: The orthogonal vector. When a pattern/mark is identified, an orthogonal vector seems to be extrapolated from that pattern and the AR activity or model is generated from that reference. I'm attempting a very simple operation: 1) ID a unique pattern. 2) Define the orthogonal vector. 3) Output the position and orientation relative to that orthogonal vector (pose). What are the terms that describe this? What is the common name of that pattern used as a target/reference? Are there projects that can be leveraged that are dedicated to that basic function? Help me get grounded! Thanks!