This tool is not available at this time.
The OpenCTM format is a highly compressed (lossless compression) format for 3D mesh objects. The format is supported in the three.js Javascript WebGL graphics library.
This utility can be used to convert a range of 3D mesh file formats (.stl, .ply, .3ds, .dae, .obj, .lwo, .off) to the .CTM format. To use the utility simply select a file and click Convert.
Note: The OpenCTM tool and associated documentation can be found on the OpenCTM page.