Hi,

I'm trying to understand how houdini cooks nodes with copy stamping.

In the example below, if there is no stamping, when I change a parameter on box6, box6, merge46 and copy13 are cooked, according to the performance monitor. I guess since sphere2 hasn't changed it doesn't need to be cooked.

Now if I stamp a parameter in sphere2, and I change a parameter in box6, sphere2 gets cooked 4 times (the number of copies).

I guess it's because the different copies aren't cached, only the output of sphere2.

Now is there a way to have sphere2 not to cook, if I change parameters on box6 ?

A way I've found is to use two different copy sops, one for the box and one for the sphere, and merge these together, but it's not very elegant, especially with more complicated networks.

This may seem a useless post, but it's just to make sure I got it right!
Thanks for reading. Suggestions welcome!

Vincent

edit : another thing I've discovered is that if I have a custom parameter on a node which has a stamp param, nothing gets cooked when I change this param, I have to bypass/unbypass the node to get the update. Is this the expected behaviour ?

I think what happens here is that changing a parameter on box6 “dirties” the chain that box6 is in. That includes the merge. That then forces the merge to cook its inputs, one of which is the sphere, hence that cooks too.
Your solution of seperating the two copy stamps is probably the only way to stop this.