Anatomy-Based Human Modeling for Virtual Reality (VR)

Introduction

Human model modeling and animation have long been a research goal in the aspect of computer graphics. Computer human modeling can be widely used in many areas including virtual reality (VR), surgery simulation, footwear design, gait analysis, etc. For instance, applications of human foot simulation are used in surgery simulation (Bro-Nielsen & Cotin, 1996; Cotin, 1999; Charles et al., 2021), footwear design, gait physical therapy (Yano, 2003), etc. Nevertheless, due to the complexity in the modeling of a human character, not much physics-based approach in the modeling and simulating of human foot model has been reported for VR applications. Although different approaches have been developed for interactive deformation, the performance of the simulation is still far from satisfactory.

Nowadays, there are various approaches for modeling in VR and related computer graphics applications. First of all, is the geometry-based approach to design based on the manual processes by graphical designers. This approach involves the design using a generic three-dimensional (3D) model or a statistical human model. In a generic 3D model, designers can design the human model freely based on their senses and experience. In a statistical human model, the model postures can be learned from statistical databases. The statistical databases have developed valuable tools for solving a variety of visual and graphic problems for 3D modeling. Blender, SketchUp, ZBrush, AutoCAD, SolidWorks, Rhino3D, 3Ds Max, Maya, CATIA, and other commercially accessible 3D modeling programs are currently available to help with design work. Autodesk 3Ds Max is a 3D computer graphics software that has gained popularity among both professional and amateur animators due to its versatility. It provides effective, rapid, and efficient performance and workflows to help increase the processing complex's overall efficiency. Autodesk Maya is another popular 3D animation program. Maya also comes with a simple simulation tool. Cinema 4D, unlike Autodesk 3Ds Max and Autodesk Maya, is not only popular among animators, but is also recommended for beginners because it is less complex than 3D Studio Max and Maya.(Hendriyani, & Amrizal, 2019). Professional and industrial applications are among the most often utilized modeling tools. These tools are used not only for computer-aided design (CAD), but also for computer-aided engineering (CAE) analysis, additive manufacturing (AM), and 3D printing. (Tang, & Ho, 2020).

Another approach is based on computer simulation methods. The methods including physics-based and anatomy-based approaches. Simulating human walking is a difficult topic from the standpoint of computational analysis. In the research, inverted pendulum models, passive dynamic walking, and approaches based on zero moment points have all been used to generate realism and natural human walking using mechanical models (ZMP). Simulation science has advanced significantly in recent years. The literature on human walking simulation is mostly divided into two categories: biped robot research and physical mechanics study. Real-time biped walking control is a major topic in robotics, and simpler walking models such as inverted pendulum models and passive power walking are commonly used for this. Furthermore, the ZMP-based trajectory planning approach seeks to follow the pre-planned ZMP trajectory. (Refai et al., 2019). Although biped robots have made significant progress in walking synthesis, many aspects of human walking cannot be replicated by biped robots. Gait analysis based on biomechanics and musculoskeletal models can provide more physiological information about human walking. Muscles, weariness, and injuries are all hot topics in science right now. (Xiang, Arora & Abdel-Malek, 2010).