3d45a33190
Each mjEQ_FLEXSTRAIN equality now represents a single cell within a flex. This allows for more efficient sparse Jacobian computation by only considering the degrees of freedom of the nodes within each specific cell. This change gives a speedup of about 10x on a 3x3x3 model. PiperOrigin-RevId: 902164069 Change-Id: I78eedf1d5cf39b8989fe9863c22d164922fc0efb