6c7ed66781
This change introduces a `flex_cellcount` field to `mjModel` to specify the number of cells in each dimension for interpolated flexes. The stiffness computation, passive force calculation, and Jacobian derivatives are updated to operate on a per-cell basis, significantly improving performance by localizing computations to the nodes within each cell. PiperOrigin-RevId: 901216393 Change-Id: Ic23132e609de11e71bb7fef8d1f139daad2ec264