Inspired by techniques like holographic vector field electron tomography (HVF-ET), this tool helps you understand how arrangements of magnetic domains (regions of uniform magnetic alignment) create magnetic fields and domain walls at a conceptual level.
Click "Add Domain", then click inside the gray material square to place a domain. Click an existing domain to select it. Use the slider to change its magnetic orientation (arrow). Small gray arrows show the calculated magnetic field. Lines between domains with different orientations are 'domain walls'.