Table 2. Processing times by unstructured grid volume rendering algorithm of VTK for three different datasets. For the ray-casting step, it uses thirty-two CPU threads by employing on Kim’s parallel algorithm[6].

	Connectivity Info. build	Ray-casting/frame
Dataset 1	9.33 sec.	1.11 sec.
Dataset 2	1007.05 sec.	8.15 sec.
Dataset 3	2063.04 sec.	2.29 sec.