Haptic simulation of rheological objects with Verlet integration

In virtual reality, educational simulators are expected to be enhanced the learning effect by representing haptic feedback, the feeling of touching objects, in the virtual world. The haptic feedback can represent more realistic feel of a material, such as the softness. For example, it is the feel of cutting organs in medicine and mixing foods in cooking. Therefore, the haptic feedback can produce experiences closer to reality, and more realistic learning effect can be expected in virtual world. However, deformable objects in the virtual world, such as organs and foods, are fractured by adding strong force generated by touching them, and normal simulations are difficult in the situation. Then, for solving this problem, we applied Verlet integration, whose example of the application is few in conventional haptic simulations, to calculations of deformable object positions for achieving break-proof deformable objects. For showing that deformable objects which are applied Verlet integration are break-proof, we compared the robustness of Verlet integration with other methods in the same situation where each method is applied to a deformable object. As the result, we verified the situation in which the only deformable object in which Verlet integration is applied is not fractured, and we showed that Verlet integration is more suitable for deformable object simulations than other methods are.