Adjusting part/vessel mass in flight

[TiktaalikDreaming]

I'm maintaining the USAF Orion mod, and it's been noticed that vessel mass is not decreasing as pulse units are expended.  I chucked in some diagnostic logging and what seems to be happening is the parts (essentially custom fuel tanks) are decreasing in mass, but the vessel isn't.

So, adjusting the mass of a pulse unit magazine is done with this super complex formula;

                    this.mass = (this.bombStockpile * this.bombMass) + this.dryMass ;
                    Debug.Log("[USAFOrion] adjusted mass of magazine " + this.bombStockpile + " to " + this.mass);

With my little debug line.  And mass (and bombStockpile) decrease as the units are used up.

But when I add in;

Debug.Log("[USAFOrion] Nominally this should have updated the vessel mass.  It now shows : " + vessel.totalMass);

the vessel doesn't change mass at all.  Even if I run 

            vessel.UpdateResourceSets();
            base.onPartFixedUpdate () ;

which would seem to be the sort of thing you do to recalc vessel things.

So,

A: Am I adjusting the part mass at all, or just some value that doesn't actually come into play anywhere?
B: If (A:), is there a way of triggering KSP to recalculate mass (and CoM) of the vessel? 

 

[Crzyrndm]

Don't adjust part mass directly (since 1.0 if memory serves). You need to implement the IPartMassModifier interface (alternatively just use a resource?).

Example implementation: 
https://github.com/Crzyrndm/B9-PWings-Fork/blob/master/B9 PWings Fork/WingProcedural.cs
https://github.com/Crzyrndm/B9-PWings-Fork/blob/master/B9 PWings Fork/WingProcedural.cs#L3312-L3322

[TiktaalikDreaming]

9 minutes ago, Crzyrndm said:

Don't adjust part mass directly (since 1.0 if memory serves). You need to implement the IPartMassModifier interface (alternatively just use a resource?).

Example implementation: 
https://github.com/Crzyrndm/B9-PWings-Fork/blob/master/B9 PWings Fork/WingProcedural.cs
https://github.com/Crzyrndm/B9-PWings-Fork/blob/master/B9 PWings Fork/WingProcedural.cs#L3312-L3322

If I was working from scratch I think I would use a resource without a second thought, and just make sure it's only ever used in discrete amounts.  But there's a lot of code already in place, so I'm trying to just get the existing stuff working.

Having a look now at the IPartMassModifier.

Thanks

[Shadowmage]

Indeed, the IPartMassModifier is the way to do it.

If you need any pointers on exact implementation, feel free to ping/PM me.  I'm more than a bit familiar with its use and setup.

[TiktaalikDreaming]

This,  try something, compile, reload ksp, look at logs, repeat cycle is reminding me of that module I need that let's me reload modules without closing the game. Jeebus. 

[TiktaalikDreaming]

I'm suspecting I'll need to not be extending Part, but PartModule to make this work.  rewrite time coming up.  :-(