Merge pull request #2 from chunmingchen/master

rendering
The forth commitment
Merge commit '31dce7e'

Conflicts:
	CMakeLists.txt
Merge branch 'master' of https://github.com/thwei/VR
correct initialization and math function problem

1. it cannot be compiled if do initialization in header file.
2. type casting for sqrt command
Merge branch 'master' of https://github.com/thwei/VR