LOD with VDPM

I have built a model which using Level-of-detail and VDPM.

First using Virtual Planet Builder to convert Grand Canyon data to OSG polygon data,
then convert it to VDPM data.

This is the screenshot:

The convert batch file can be found on \vdpm\data\gcanyon_conv.cmd at https://github.com/kctan0805/vdpm

Video:
https://youtu.be/3anybmyYP10