For example, i have non manifold mesh, and want to compute the mass of mesh like if it is made of steel or wood.
Is there such addon? Or may be i can use some other program, or online service?
i might have found one method, but im not in the mood of doing math and shitâŚ so ill let that up to you.
if the following statement is true, then my method works.
DO THE MATH TO CHECK!
Statement:
A cube that is 2x2x2 meters made of solid gold will have a mass of 154.256tonn
method:
select the mesh, apply scale by hitting CTRL + A, go to the physics tab in the properties and enable Rigid Body, then in the tools panel, go to physics and click Calculate mass (in this case i selected gold), then look in the rigid body properties and there should be a Mass value. from there you can find the density of whatever material you chose, and from there you can calculate the volume.
also, turn on metric units if you havent already
If the mesh is non manifold, wouldnât that make getting a mass impossible?
I donât know. I never try to calculate mass of nonmanifold mesh.
Itâs easy, add a fluid sim and inflow, fill the non manifold mesh with honey, delete the mesh, apply the fluid sim, 3d print the fluid sim mesh, weight it on a triple beam balance, and then divide by the plasticâs density.
for non manifold you must separate the different parts to get manifold meshes
then you can calculate the volume and sum all the parts
there is a script some where to calculate volume for manifold mesh
happy bl
I think I misunderstood your original post, were you asking for a way to get the value for a mesh that is not closed?
Waterproof does not say if it is manifold or not
happy bl
Alternative
Ď = m / V
Ď = density (kg/m[SUP]3[/SUP])
m = mass (kg)
V = volume (m[SUP]3[/SUP])
So all you need is to get the Volume

Measurement Tool addon: https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Neuro_tool/Measurement

MeshLab has: ââŚ a measurement filter that computes volume, surface, inertia tensor, topological invariants, manifoldness etc etc.â
watertight and manifold, I believe, are the same thing
EDIT I should say closed manifold, as there can be open manifolds as well
as I remember watertight just means closed volume and no holes !
can be manifold or not !
happy bl
well point was you can use this method to gain data to calculate the volume and mass of whatever object you want.
even nonuniform once.