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### Dark Physics & Dark A.I. & Dark Dynamix / Forces

Message
Posted: 5th May 2010 17:57
Hi, I am trying to figure a calculation to get how much weight to "add" to simulate buoyancy,

There is a constant up force to simulate the buoyancy, with a set of controls to add weight for ballast.

Neutral ballast needs to be intelligent so it can add/remove ballast to keep the object from sinking or floating.

The problem lies in up force as the power of the up force seems to change although I'm not telling it to change. The strength of 1 unit of up force seems to be variable. Just as I find the weight required the next time I run the game it isn't neutral anymore.

Does anyone know how to calculate how much weight can be lifted by a given force?

EEEK
Posted: 5th May 2010 23:42
Does it have anything to do with the frame-rate?
If you apply force every frame then the frame-rate may be having an effect, I am just guessing though.
In the PhysX examples they always multiply any force by the timestep between frames, I don't know if Dark Physics does this behind the scenes or you need to do it yourself.

Posted: 6th May 2010 02:11
It has an auto timing command (I forget it off hand). It seems to work for me, but I'm not needing it to be ultra-precise like this. It could be the mode for the force...maybe. That also determines how the force is applied over time.
Posted: 6th May 2010 14:41
not entirely sure what you are trying to achieve. Is this a hot air balloon, ship or submarine type buoyancy you are talking about

is your buoyancy force a constant? or is it controlled by an equation

is your 'weight force' a constant? or are you using inverse square approximation?

This is not the Sig you are looking for....
Posted: 7th May 2010 13:33
the object is a submarine.

The buoyancy is constant and so is the weight of the sub, am just looking for a way for getting the ballast controls to be more reliable, as one go they are about right, then ya change something somewhere even if its unrelated and the buoyancy force seems to be a little stronger.

EEEK
Posted: 7th May 2010 15:03
@matty halewood

You were right in your poke at the FPS, the higher the FPS the more force it was giving.

Thanks for everyones help.

EEEK