forEach and clip SOP

[etudenc]

Hi all,

I am trying to figure out how to cut a 2x2 grid into (let's say) 10 random primitives. I feel sure the right way to do it is thru a clip SOP inside a forEach SOP, but the thing is I want each new primitive to be affected by the clip SOP and not the "previous" primitive(s) or the entire grid.

Hopefully the image I've attached will help illustrate what I'm after.

Thank you for any responses!

[Erik_JE]

You need recursion for that. A ForEach won't be enough. I don't know how to do that with nodes tho.

Edited October 10, 2011 by Erik_JE

[mikelyndon]

Hey dude.

Have you tried using the voronoi fracture tools? That might be a more elegant solution to your problem.

Mike

[Tom]

If this is what you want, then you can check attached files.

But im not using "cut" method. Im doing that with point node.

test01.hipnc

test02.hipnc

Edited October 10, 2011 by Tom

[sam.h]

Had a play with this, there is something wrong with the way I am getting the seed for the random direction for the cut ... but it basically works.

It is a nested foreach, the top layer is a foreach feedback loop, and the inner foreach is for each connected piece (so that you can get a different cut for each piece)

recursiveCut.hip

[rdg]

I did something like this awhile ago with nodes:

I think I used the clipSOP.

[edward]

You need recursion for that. A ForEach won't be enough. I don't know how to do that with nodes tho.

One can simulate recursion using iteration through the use of a stack. It's bit of pain but I've done it before. You make a string attribute say that has a list of your primitive numbers (separated by spaces). Then through string manipulation, you can "pop" items off the stack by removing the last primitive number, and you can "push" an item onto the stack by appending your primitive number.

[etudenc]

Wow, thank you for all the helpful responses and example files! The nested forEach SOPs are particularly interesting.

Thanks so much!

[Erik_JE]

One can simulate recursion using iteration through the use of a stack. It's bit of pain but I've done it before. You make a string attribute say that has a list of your primitive numbers (separated by spaces). Then through string manipulation, you can "pop" items off the stack by removing the last primitive number, and you can "push" an item onto the stack by appending your primitive number.

I get the idea of using a stack but not how to use it together with a ForEach or some other node.

If doing it by code i would make a stack of primitive numbers with a pair attribute being the depth of how many times they have been recursively clipped.

Then pop-ing one from the top, clipping and ++ the depth and add them on the stack again. Use a random number to decide what depth that are allowed for the individual primitive. Keep looping while there is anything on the stack.

I would love to see an example on how something similar could be setup with nodes.

[edward]

Keep looping while there is anything on the stack.

Yes, the problem is that you don't know when to stop but that's ok. Just give it a high enough number of iterations to ensure that you reach a state where your stack is empty.

[Erik_JE]

Yes, the problem is that you don't know when to stop but that's ok. Just give it a high enough number of iterations to ensure that you reach a state where your stack is empty.

Ahhh, using the Each Number of course. Got my string of primitive numbers now and most other stuff. Just need to figure out how to modify the string.

[Erik_JE]

Here we go if anyone is interested.

String stack recursive using ForEach.

recursiveSplit.hipnc