Calculate weight of vessel ?

[pixartist]

I have mainBody.gravParameter and the vehicle mass. How do I calculate the vehicle weight from that ?

edit: I don't think mainBody.gravParameter is what I thought it was. Where can I get the current gravitational acceleration ?

Edited October 27, 2014 by pixartist

[MoreUmpf]

You can use the gravParameter:

weight = mainBody.gravParamter * (vehicleMass / (mainBody.Radius^2));  // weight in N

EDIT: sorry, forgot that it was radius²

Edited October 27, 2014 by MoreUmpf

[Diazo]

You have to come at this backwards because I believe KSP cheats and simply accelerates everything in m/s to simulate the force of gravity.

So, as follows:

//3 lines known good as I use them myself in my velocity control mod
VesselMass = Vessel.GetTotalMass(); //vessel mass, including resources
GravHeight = (float)Vessel.altitude + (float)VesselSOI.Radius; //distance to calculate gravity force, is altitude from body center
GravAccel = (float)TWR1SOI.gMagnitudeAtCenter / (float)Math.Pow(TWR1GravHeight, 2); //accel down due to gravity in m/s^2, can't remember where i found this formula but it works 

//don't use this line myself, but it's straightforward math, only catch is if KSP uses the same units I'm thinking it does
VesselGravForce = GravAccel * VesselMass; //should be gravity's force in newtons on your vessel

Hope that helps,

D.