A mixed-depth visual rendering method for bleeding simulation

The visual fidelity of bleeding simulation in a surgical simulator is critical since it will affect not only the degree of visual realism, but also the userʼ s medical judgment and treatment in real-life settings. The conventional marching cubes surface rendering algorithm provides excellent visual effect in rendering gushing blood, however, it is insufficient for blood flow, which is very common in surgical procedures, since in this case the rendered surface and depth textures of blood are rough. In this paper, we propose a new method called the mixed depth rendering for rendering blood flow in surgical simulation. A smooth height field is created to minimize the height difference between neighboring particles on the bleeding surface. The color and transparency of each bleeding area are determined by the number of bleeding particles, which is consistent with the real visual effect. In addition, there is no much extra computational cost. The rendering of blood flow in a variety of surgical scenarios shows that visual feedback is much improved. The proposed mixed depth rendering method is also used in a neurosurgery simulator that we developed.