Shows a non-rectangular 2D integration region R partitioned into grid cells (ΔA), highlights a moving differential element dA, and builds the signed volume under z=f(x,y) using Riemann-sum boxes. In the latter part of the animation, a scanning slice illustrates Fubini’s theorem by accumulating the same total via different iterated-integration orders (dx then dy vs dy then dx).
Pure Canvas2D rendering with a snapped grid for a retro blocky aesthetic. Uses time-based phases (4.2s loop): partition refinement + Riemann-sum assembly, then Fubini scanline highlighting. Volume is drawn with a lightweight pseudo-3D projection and per-cell extrusion; positive/negative heights use different green intensities to emphasize signed volume.