s3d_angle_to_cam(3)

NAME

s3d_angle_to_cam - calculate angle between vector and cam

SYNOPSIS

#include <s3d.h>
float s3d_angle_to_cam(const float obj_pos[], const float cam_pos[],
                       float *angle_rad);

DESCRIPTION

Given obj_pos and cam_pos in the format float[3], angle_rad about which angle the object should be rotated around the y-axis so that it faces
the camera. This might become handy if you have some text floating in
space and want it to face the camera.
http://en.wikipedia.org/wiki/Vector_(spatial)

AUTHOR

Simon Wunderlich

Author of s3d

s3d S3D_ANGLE_TO_CAM(3)