Nikola Tesla

“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.”


― Nikola Tesla

ARCBALL

회전축과 회전각도를 결정하여 회전 Quaternion 을 구해냄.

마우스 입력으로 3차원 회전축과 각도를 어떻게 결정하는지 알면 끝.

현재점과 anchor 점을 결정할 때 2D 입력을 spherical mapping을 사용하여 3D Vector로 mapping.

본 논문 : 

ARCBALL: a user interface for specifying three-dimensional orientation using a mouse
http://dl.acm.org/citation.cfm?id=155312

예쁜 구름

지난 10월초 유럽의 어느 하늘 위. 

#pragma warning(disable : 4244)

#if (_MSC_VER)      
// make microsoft visual studio complain less about double / float conversion.
#pragma warning(disable : 4244)
#endif

ofQuaternion.h 에서 참고

Take Screenshot After Some Delay: gnome-screenshot

$ gnome-screenshot -w -d 2

 -d 2 is used for delaying the screenshot for 2 seconds. So within the 2 seconds, we can make the window which we want to take screenshot as active.