An Efficient Navigation Method for Virtual Endoscopy Using Volume Ray Casting

In virtual endoscopy, it is important to devise the navigation method that enables us to control the position and orientation of virtual camera easily and intuitively without collision to organ wall. We propose an efficient navigation algorithm that calculates depth information while rendering a scene for current frame with volume ray casting method, then computes new viewing specification of camera for the next frame using the depth information. It can generate a camera path in real-time, allows us to control the camera with ease, and avoids collision with objects efficiently. In addition, it doesn't require preprocessing stage and extra storage for maintaining spatial data structures. Experimental result shows that it is possible to navigate through human colon when we apply our method to virtual colonoscopy.