foreach problem [H14]

[j00ey]

HI

 

I have a problem with a couple of nested foreach SOPs that I can't for the life of me figure out.

 

I have a load of spaghetti-like tubes and I want to add a random number of randomly sized gaps to each. I thought this would be relatively straightforward but it's just not working.

 

I've put down a foreach primitive, and inside that a foreach number - on this one I generate a random maximum number,  then inside of that I put down a carve SOP to make the random gaps but it's not behaving as I'd expected. I'm only getting back my first prim, but copied a lot of times [with carves]

 

I've made a simple scene to demonstrate the problem. Can someone tell me what I'm doing wrong?

gappy_tubes.hip

[Atom]

When you use nested FOREACH you have to remember to change the index variable of the second one to a unique name or the second one will clobber the first one's value.

 

Like this...

for (i=0; i < 10; i++) {
    for (i=0; i<2; i++) {
        //do work.
    }
}

In this case the index variables are the same and the loops won't work right.

[j00ey]

Ah I hadn't thought of that but it makes total sense. Thanks very much for the pointer.

[Maurits]

Also i think you need to disable in your'e second foreach the merge result option else it merges the result of each iteration together.

To get a different gap pattern for each tube you also need to add both foreach indexes to the random value in the carve node.

 

 

 

 

[j00ey]

Yes I just discovered I needed to switch off the merge results.

 

Thanks for the tip regards the for each indices though, I was just trying to figure out why the pattern is otherwise quite uniform