JBox2d: set fixture mass

[deepthought]

does anyone know how to set the mass of a fixture in jbox2d? the only way i found is to set the density, and the engine sets the mass based on density and area. how can i just set the mass if i already know it?
Thanks!

[deepthought]

I think if I subclass polygon shape and override set mass I can do it that way, but how do I figure out mass data.I and the centroid?

[matheus23]

No!
Use

Body#setMassData(massData);

, and then use a

new MassData()

and set it's

massData.mass

value. But mind, that you also need to know the center of mass.

I suggest simply using density

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[deepthought]

The problem is that the mass of my entities is not related to their area.
I'll probably copy the area code and put it in a getarea()  function then divide the ass by area to set density.