Previous work on 3D freehand photoacoustic imaging has focused on the development of specialized hardware or the use of tracking devices. In this work, we present a novel approach towards 3D volume compounding using an optical pattern attached to the skin. By design, the pattern allows context-aware calculation of the PA image pose in a pattern reference frame, enabling 3D reconstruction while also making the method robust against patient motion. Due to its easy handling optical pattern-enabled context-aware PA imaging could be a promising approach for 3D PA in a clinical environment.