c# – calculate projectile velocity from transferring shooter

I’ve a process which i’ve a transferring ship that may shoot in any course i need. i’ve to shoot to standing or transferring close by objects.

the issue is, I can not appropriately calculate true shoot course.I need to discover a course after ship velocity apply on it then bullet go to focus on place.

Ship shoot methodology :

public void shoot(vector3 course)
{
   var projectile=  new Projectile();
   projectile.Velocity = Ship.LinearVelocity + Vector3.Normalize(course) * Ship.GunInfo.ProjectileSpeed;
   projectile.Place = Ship.Place;
   World.Add(projectile);
}

Projectile replace methodology :

public void Replace(TimeSpan deltaTime)
{
    Place+= Velocity * deltaTime;
}

So what’s true course which should to be handed into shoot methodology?

I attempted bellow calculations :

1- first answer i attempted to shoot targets : (actually unhealthy accuracy)

var baseDirection = goal.Place - Ship.Place;
var course = baseDirection - Ship.LinearVelocity/Ship.GunInfo.ProjectileSpeed;
shoot(course);

2- second answer i attempted to shoot targets : (higher accuracy)

var baseDirection = goal.Place - Ship.Place;     
var shootDirection = Ship.LinearVelocity + Vector3.Normalize(baseDirection) * Ship.GunInfo.ProjectileSpeed;
var course = Vector3.Replicate(- shootDirection, Vector3.Normalize(baseDirection))
shoot(course);

• All velocities (ship, projectile) are vector3.

• I do not use any physic engine however i’ve vector3 math capabilities like (normalize, undertaking, dot, …).

• Normalize imply vectorA/size(vectorA) meaning vector with size one

• ship pace at shoot time is fixed however periodically change velocity and course.

• there is no such thing as a gravity,wind and so on all velocity stay fixed besides ship that change its method.