# paper simulation

I am trying to figure out the cloth physics, but I'm running off an old Mac laptop, and it's taking forever to run just 5 frames to test the settings. So does anyone know what kind of settings I should use to simulate a piece of paper. I just need it to settle, so I can capture a still frame, I'm not making an animation. I thought if I make the settings high, then the cloth settings will be stiff, but nothing I do looks any different from this. I can't find anywhere of someone explaining how to make it act like paper.

And yes I can see the there is a gap between the paper and the surface It's supposed to settle on, but once I get the look I need ill just lower it on the z axis where I need it. My main issue is the paper simulation.

I lowered the subdivide.

I used leather, lowered the vertex mass to .15 and raised air viscosity to 3. I raised the tension, compression, and shear to 300

• How dense is your paper sheet? The mesh looks way too dense when it can adapt and reveal the underlying structure (and this would be also a reason why your laptop takes forever to calculate just 5 frames). Aug 1, 2021 at 3:34
• I added a new photo. I thought you are supposed to subdivide it a lot when you want to use the cloth sim. I even have the subdivide modifier on lvl3 also. Aug 1, 2021 at 3:47

If you want a super-adaptive material like wet paper, hot cheese, a vacuum sealing then a lot of geometry is needed, like in your screenshots.

Dry paper is a very stiff material. Think of the pages of a book. Here a low-poly mesh helps to get the stiff effect because the cloth simulation can't bend single triangles. The green sheets are subdivided 20 times (441 faces). They use the Leather preset for the settings but Cloth > Physical Properties > Vertex Mass to lowered to 0.3 kg. The Cloth > Collisions > Object Collisions > Distance is 0.001 m for the sheets.

For comparison, the purple sheet has fewer subdivisions but the Denim preset (=less stiff) and also a reduced Vertext Mass (0.3 kg).

If the Vertex Mass is too high the sheets crush like a stone through the cube.

All objects - except the purple sheet because it's on top - have Collision physics with Collision > Softbody & Cloth > Thickness Outer set to 0.002. No Self Collision (disabled).

It's difficult to avoid gaps between the sheets when using real-world scale because paper sheets are so thin and you can't lower the collision distance to such a low value. At some point, the collision detection fails and the paper falls through an obstacle. Or the whole stack of paper sheets just explodes or it starts to crumble itself. (This is also true for soft bodies and other physic objects.). So there is always a little gap between the objects.

Related info: Ian Hubert used Soft Body physics to make his animating flying papers/bags in Blender

You can keep lots of geometry in your paper simulation for good simulation accuracy, you just want to switch the bending model from Angular to Linear in the cloth's physics materials. You should immediately see the change from a crumpled/wrinkly simulation to a nice smooth simulation.