How Add Volume to Cloth Simulation?

how can i add volume to clothes? I want to model a beanbag but when i simulate it normal
it’s just flat like a blanket.

Cloth simulation is really only for sheet-like objects. You can certainly use it for an enclosed object like a sphere/beanbag but it will be an empty shell. The way a beanbag behaves in reality is because it’s filled with something that keeps it from collapsing on itself. What you get with a pure cloth sim is more like a deflated balloon.

To get a more beanbag-like behaviour, you are better off using softbody simulation. However, for a large or complex mesh this still might not get you what you need because once again, the simulation works only with the mesh geometry and there still isn’t anything inside the bag so it easily collapses in on itself.

I have tried to do similar simulations many times and have found a few workarounds (neither is perfect).
First, you can add additional geometry to your model to help the softbody work better. This really only works for roughly spherical shapes. The method is this:

  • select all vertices and duplicate, making sure not to move the vertices.
  • extrude>individual faces but again confirm the action without moving any vertices.
  • Without changing your selection, scale the vertices down (this is where you have problems if your mesh is not roughly spherical - the scaling will not match up with your outer shell correctly)
  • Select all, remove doubles

What this technique does is create a layered structure inside your mesh connected to the outer layer by quads which will have softbody stiffness. The softbody will now behave like a thick shell rather than an empty balloon. It is much less likely to collapse on itself.

Second method: use the Molecular addon with a particle system generated by your base mesh. This might not be perfect for a beanbag because it will act like a bouncy solid object rather than a shell filled with loose grains, but it might work for your purposes. Disadvantages of this method are that you need a lot of particles to get a smooth outer surface, which requires long bakes. It’s also a bit more work to texture the resulting particle system (it can be done using the CubeSurfer addon by the same author).

Edit: A third method (untested by me) might be to keep the bag as a cloth sim object but actually fill it with rigid body colliders or perhaps particles. Again, this would get expensive to simulate if you consider just how many “beans” are in a typical beanbag…I’m also not sure if you could really get the cloth to “contain” the colliders without them clipping through during simulation.

Thanks, i wil try it.

Don’t recall who sugested, but in some thread about pillows, someone did mention using force fields to inflate a cloth object… may also work.

For so little things like pillows this method mit force field works fine but with big objects like bedcover i didn’t have good results.

The pillow force field method is quite neat, thanks for mentioning that Secrop.

Another method you might try (for a bedcover, not the original beanbag example) is simulate a flat plane cloth and apply a solidify modifier followed by a displace to create the puffy quilted areas. I’m attaching an old image that used this technique for a lightly-quilted satin - you might be able to scale that up for a bedcover.