Three-dimensional virtual method, computer program and system

To shorten a period of designing. ÄSolutionÜ A curved state and other states of a wiring harness are displayed by dividing wires into wire segments and applying a polygon processing, and are compared with a 3D shape of the wiring harness represented by a reference layout data displayed as a background image. As compared to a case where a trial product is produced, an operation efficiency can be considerably improved.