Reconciling anātman and ancestor worship/veneration

Buddhism teaches the concept of *anattā* or *anātman*. In short: >There is no "soul" or "essence", only "processes" within the framework of the five *skandha*s. This gives the illusion of the individual self/soul. *NOTE: This is just an approximation. I'm sure it can be put more elegantly, but you get the picture.* With this understanding, what is the basis for ancestor worship/veneration? Who/What is being honoured or worshiped? Basically, how do practicing Buddhists reconcile the two world-views? Is it about remembering shared experiences? Or a way of remembering family traditions and history? Any insights are appreciated!