(a) Tracking prediction using a low-bending model and (b) a high-bending model, which uses a higher order polynomial, fits fewer points and predicts less far into the future; open circle is the current prediction. Processing: (c) original root, (d) 40 pixel mask based on angle of growth (e) mask contents, lateral detection regions marked. Outputs: (f) lateral detection, (g) original image showing a sharp gravitropic response. (h–j) Results of applying increasingly tracking-capable models using the blender bar; color indicates local curvature (red for high, blue for low).