Soft Body Simulation 'Magnetizing' to Collision Object

Hi all,

I’ve been working on a soft body animation where a sphere inflates within a glass box. Originally, I attempted to use a cloth simulation, but I was having trouble inflating the cloth correctly, so I opted for a soft-body with a force-field to fill the space. In the below pictures, I tested my soft body with a series of cylinders, to make sure that my subdivisions would allow for a decent amount of deformation.


However, when I tried the same sphere in the intended box, the sides of the sphere seemed to ‘magnetize’ to the sides of the box, shown in the below image. I’m not sure what is causing this attraction, but it doesn’t seem natural and tends to bog down the baking of the animation.

The final result is decent enough, but I wanted to know it was possible to stop this ‘magnetization’ and lower the simulation baking time. If I wanted to work on a larger-scale animation, I don’t think Blender would be able to handle it. Any advice on using the soft body or suggestions with shapekeys/cloth would be appreciated!


The question is: do the sphere ‘magnetizate’ to the cylinders? (Not visibile on your images) And does the box have a ‘decent’ subdivision (no wireframe image)? Also your test is on convex body and you target has plane sides… One posibility is that if you used a UV-sphere the sides are not equal distribted so maybe try a ico sphere?

The sphere doesn’t seem to magnetize to the cylinders, and it seems to work correctly in this case. The box itself had several subdivisions along the contact surface, and the object that I used was actually a subdivisioned cube. I can try a sphere and see if that helps, but I’ve noticed this effect on other soft body physics simulations that are more complex. The sphere in the box was a test animation to figure out if the issues stemmed from the complex mesh, or a lack of understanding of the soft body itself.