1. A method for generating modified video, the method comprising: (1) acquiring a source video comprising a sequence of 2D image frames; (2) obtaining from the source video an image frame that includes two or more motion vectors that describe motion in the image frame, wherein each of the motion vectors is associated with a region of the image frame; (3) calculating a respective parameter for each of the following: (a) a lateral speed of the image frame, using the two or more motion vectors; and (b) a direction of motion of the image frame, using the two or more motion vectors; (4) generating a deformation value by applying an algorithm that uses both of the parameters; (5) applying the deformation value to the image frame to identify a modified image frame; and (6) blending the modified image frame with a bridge frame that is a non-solid color and is different from the modified image frame, to generate a blended frame; wherein the direction of motion and velocity of motion parameters in the calculating step are calculated only from the motion vectors input along with the image frame.