A hand gesture input device, called Leap Motion, has been utilized in virtual reality artworks since 2012 to capture hand and finger motions, with comparatively reliable precision. The device detects all the coordinates of the finger joints, as well as the positions of both palms and wrists in real time. Although many implementations have been proposed, some difficulties remain for grabbing or releasing 3D objects with the virtual fingers. Each of the fingers as well as the palms has its own collider, to detect collisions with objects, but sometimes it simply bumps against objects, pushing away them, unable to hold objects stably in the palms. I attach  an inner collider and an outer trigger to an object to interact with finger-tip triggers for smoothly grabbing and releasing the object.