If you need a line trace then - use the deprojected point as a line trace start then use the direction vector miltiplied by a projectile max distance and add it to the deprojected point and you will get the line trace end point.
If you need a line trace then - use the deprojected point as a line trace start then use the direction vector miltiplied by a projectile max distance and add it to the deprojected point and you will get the line trace end point.