It's a quite noob question but I can't figure it out:

In this typical Vellum setup, Vellum Source pulls data from an SOP node and put it into the vellumobject1 DOP object.



But how does it know where to put the data? It doesn't have a parameter referencing to the vellumobject1? There isn't even dependency between these two nodes!

But if you really want to know, check out this class:

https://www.sidefx.com/tutorials/masterclass-fluid-solvers-from-scratch/ [www.sidefx.com]

It's unrelated except that it gives a good sense, I think, of how things work in DOPs.