Abstract: By taking the symmetry error for flatness to flatness as an example, the specific
web-based method for the visualization of tolerance of form and position is discussed and the
mechanisms of communication and interaction theory between VRML and Java are clarified.
Simultaneously, with VRML as the 3D displaying platform and Java Applet as the controlling
core, the visualization of symmetry error for flatness to flatness is presented as an instance. Users
can directly observe the position of the reference central plane and the distribution of measure
points in the screen. So, it provides a foundation for amending unqualified parts and improving
follow-up process.

Key words: computer application, symmetry error, visualization, VRML, Java Applet