Hello,
Based on that visualizer, here’s my two cents: I believe they defined some key point clouds for some parameters (e.g. 1.70m 70kg male, 1.80m 70kg male, 1.70m 80kg male…) and use some point cloud morphing algorithm to compute and render intermediate body models for non-key parameters on the fly. I don’t believe simple linear scaling would result in realistic body models.
take care,
Paulo