• The center of vision (COV) coincides with the cube's center (i.e., imagine you are looking directly through the center of the cube).[br]• Draw the eight remaining edges of the cube inside the gray area, then check whether your drawing is correct.[br]• Click the 'Compare' button repeatedly to switch between your cube and the correct cube.[br]• Use the gray slider and the blue slider to adjust the field of view (FOV) and the cube's dimensions, respectively.[br]• Keep the FOV low (~20-30°) if you want to practice drawing more natural-looking cubes.[br]• Toggle 'Show horizon line' to reveal the horizon line (in most cases it will be out of view).[br]• Toggle 'Show edge' to reveal one of the cube's edges (however, you should still draw over it).[br]• Toggle 'Show normal' to reveal the normal (perpendicular) vector, which points toward the cube's center.[br]• Use Ctrl+Z/Ctrl+Y to undo/redo strokes. You can also use the arrows in the top-right corner.