Position and rotate a reticle on the floor, at the feet of a player in the 3D direction we're aiming at a range from the center

Unity3D_AimReticle.cs

Transform aimTransform;
float spriteOffsetY = 0.01f;
float aimRange = 1.5f;

// use incoming player.state.aimDirection to calculate the rotation and position of the reticle's aimTransform
Vector3 aim = player.state.aimDirection.normalized; 

aimTransform.localPosition = new Vector3 (aim.x * aimRange, spriteOffsetY, aim.z * aimRange);
float angle = Mathf.Atan2 (aim.x, aim.z) * (180 / Mathf.PI);
aimTransform.rotation = Quaternion.Euler (90, angle, 0);