[Question] What is the meanig of flags about fluidx3d

[ProjectPhysX]

Hi @Yujif1Aero, what exactly do you mean with "date of flags"?

[Yujif1Aero]

Thank you for your replying@ProjectPhysX . I couldnt undastand Toggle rendering modes with the keyboard:
1: flags in the section "How to get started?" No.4 of readme file. Is it pysics value?

[ProjectPhysX]

The lbm.flags[n] data field contains an 8-bit integer for every grid point. If it's 00000000, it's a standard fluid voxel, if it's 00000001, it's a solid voxel, if it's 00000010, it's equilibrium boundary (inflow/outflow). The other bits are used for other types.

If you have a voxelized solid geometry in the box, the "flags" rendering mode with key 1 draws the outline of the solid geometry. And it also marks inlet/outlet (equilibrium boundary) voxels and other boundary conditions, if present. These rendering modes are just for visualization, they have no impact on the physics/simulation.