Getting the velocity vector from position vectors

Question

I looked at a bunch of similar questions, and I cannot seem to find one that particularly answers my question. I am coding a simple 3d game, and I am trying to allow the player

Answer 1

An Impulse is technically F∆t for a constant F. Here we might want to assume a∆t instead because mass is irrelevant. If you want to animate an impulse you have to decide what the change in velocity should be and how long it needs to take. It gets complicated real fast.

To be honest an impulse isn't the correct thing to do. Instead it would be preferable to set a constant pick_up_velocity (people don't tend to pick things up using an impulse), and refresh the position each time the object rises up velocity.y, until it reaches the correct level:

while(entPos.y < holdingEntPos.y)
{
    entPos.y += pickupVel.y;
   //some sort of short delay
}

And as for floating in front of the player's eyes, set an EyeMovementEvent of some sort that also sends the correct change in position to any entity the player is holding.

And if I missed something and that's what you are already doing, remember that when humans apply an impulse, it is generally really high acceleration for a really short time, much less than a frame. You wouldn't see it in-game anyways.