| 摘要 |
A clipping plane is formed between a projection center position and a projection plane such that the clipping plane is parallel to the projection plane. A three-dimensional line is subjected to clipping at the clipping plane. It is determined whether respective nodes constituting a three-dimensional line in a three-dimensional image to be projected onto the projection plane exist inside or outside a view volume, by comparing z-axis values of the nodes with a z-axis value of the clipping plane with respect to the projection center position. If the nodes of the three-dimensional line exist both inside and outside the view volume, a new three-dimensional line is constructed using nodes existing inside the view volume and intersections between the current three-dimensional line and the clipping plane, or using only the nodes existing inside the view volume. |
