1. An ultrasound diagnostic apparatus comprising: an ultrasonic probe; a generating unit operatively connected with the ultrasonic probe and configured to obtain ultrasound image data from the ultrasonic probe; and a display processing unit operatively connected with the generating unit; and wherein the display processing unit is configured to render a time sequence of 2-D images from the ultrasound image data by: identifying low-information voxels in the ultrasound image data; applying time variant noise to at least one display parameter of each of the identified low-information voxels to simulate movement; and raytracing the ultrasound image data for each of a plurality of time steps.