OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Assigning Material Number For A Particle › Reply To: Assigning Material Number For A Particle November 30, 2022 at 9:22 pm #7057 mathiasKeymaster Are the particles moving or fixed? In general you can use indicators to set materials. If there is no suitable indicator available you may write your one adjusted to your needs. Best Mathias