Effects of mesh structure and mass on soft body behavior

[FilippS]

Hello, I am using RealFlow for producing a set of different scenes for soft body simulations. Ideally, I would like to compare the behaviour of different shapes in these different scenes with the same soft body properties, that is, with the same length stiffness, volume stiffness, elasticity, and internal damping. However, I found that the structure of the mesh of the objects has a significant influence on the soft body behavior. A number of cubes falling on a plane from a fixed height and gravity show quite different behavior (e.g., different relative compression) based on their mesh structure: (1) cubes with a tighter mesh are not compressed as much as cubes with less tight meshes, and (2) larger cubes (i.e., with larger faces and more volume) are not compressed as much as smaller cubes (i.e., with smaller faces and less volume) even when they have the same number of vertices. This seems to imply a fundamental problem when trying to compare the behavior of different shapes, as they often differ in the number of vertices and/or size of faces. Finally, I did not find much influence of the mass of objects on soft body behavior. My question is therefore: What is the exact role of mesh structure and mass in the simulation of soft body behavior in RealFlow? Which mesh (and other) parameters of shapes have to be equalized across shapes to simulate the effect of shape on behavior? Thank you, all the best.

[LuisMiguel]

Hi Filip.

Keep in mind that every mesh you convert to be used as softbody is going to be affected by the mesh structure, number of polygons, mass, etc. It is because there is a lattice affecting the softbodies given by the Resolution parameter which is affecting, as I said before, the mesh structure. If you want to compare meshes, you will need to do it with the same mesh, same number of vertices, same number of polygons but modifying the other parameters. If you have different meshes, obviously you'll have different results.

luisM.