Guy Rabiller schrieb:
Again, it would helps to describe some specific situation to see how
this can be handled ( if it can ).
Say you have a polygon mesh on the input for that you build an
acceleration structure. Now this might be static or shape animated. In
the final operator there might be two different states. One that needs
this data and one that doesn't. Now the optimal solution would be to
only recompute this acceleration structure if a) it has dirty inputs/the
mesh changed and b) the data is actually needed/pulled. I'm not sure how
to handle the pull part with separate operators as only connecting a
blob as input to the "master" ( formerly called C ) operator for example
makes the other operator ( A ) considered as pulled (understandable as
XSI doesn't know what you are up to). It would be easy to handle
"pulled" correctly inside the "master" operator though.
On the other hand treating it your way this structure would stay with
the object it belongs to and would be exposed to other operators which
might be handy.
PS: I'm not saying dirty flags shouldn't be exposed, of course. What
I'm saying is that if you expose them, and you push their use,
ultimatly you might end up with Operators with lots of inputs, but
with their computation done independently of the natural lazy
evaluation of the input connected object ( an object evaluation is
triggered but you don't need it - what the point ? ). Ultimately
you'll make your decision tree inside the Operator in a totaly
independent way of the XSI graph. This would defeat the natural lazy
evalulation of the XSI operator graph, I believe. But again, I'm not
against the dirty flags feature. Just trying to say that by relying on
those dirty flags too much, you might miss the oportunity to better
design your plugin.
I totally understand what you are saying. Replicating lazy evaluation
inside of an operator makes it's modules less reusable and less
transparent. It's just sometimes it would come handy.
F.
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