public void setLookAt(
			float eyex, float eyey, float eyez,
			float centerx, float centery,float centerz,
			float upx, float upy, float upz) {
		this.eyex = eyex;       this.eyey = eyey;       this.eyez = eyez;
		this.centerx = centerx; this.centery = centery; this.centerz = centerz;
		this.upx = upx;         this.upy = upy;         this.upz = upz;
		
		if(mainCamera != this) return;
		// ̃JۂɎgpȂAȉ̍Đݒ肪s
		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();
		gluLookAt(eyex, eyey, eyez, centerx, centery, centerz, upx, upy, upz);
	}