For the film, I am not sure about the answer but we can ask one of the experts here.n Array , Can you please have a look at the Eulerian wall film settings and let Array know the right procedure to initialise the film. There is an error message appeared after changing the film material. The message appears in the photos above. Thank you! nnnFor the UDM, I believe you are selecting the right number. Let's add a value to the UDM before starting. This function should put a value of 1 in all C_UDMI . After compile you should find this in the execute on demand menu. Run this before initialisation.nnDEFINE_ON_DEMAND(init_udm)n{n Domain *domain;n cell_t c;n Thread *t;n n domain=Get_Domain(1);n n /* Fill the UDM with magnitude of gradient. */n thread_loop_c (t,domain)n {n begin_c_loop (c,t)n {n C_UDMI(c,t,0) = 1;n C_UDMI(c,t,1) = 1;n C_UDMI(c,t,2) = 1;n C_UDMI(c,t,3) = 1;n C_UDMI(c,t,4) = 1;n C_UDMI(c,t,5) = 1;n C_UDMI(c,t,6) = 1;n C_UDMI(c,t,7) = 1;n C_UDMI(c,t,8) = 1;n C_UDMI(c,t,9) = 1;n C_UDMI(c,t,10) = 1;n C_UDMI(c,t,11) = 1;n }n end_c_loop (c,t)n }nnnnThese lines should check that the data is valid before proceeding in calculation. It should be used below the message Message( This is function : film_mass_source);nif(!Data_Valid_P()) n return;nnn