Bypassing cyclical data stream detection

Hello everyone,

I'm currently working on a somewhat special/silly definition using Hoopsnake + Data Rec and the cyclical data stream detection is getting into my way. Now, I truly appreciate what this feature generally prevents us from doing but in this case I'm 95% sure the loop won't brake GH as the Data Rec should actively try to prevent this from happening.

So I'd like to ask you if there's any way to bypass the cyclical data stream detection? I believe what I'm looking for is a way to send a value from an output to another input without having a "wired" connection between those two components. Any ideas on how to achieve this? Scripting?

Thanks.

PS: Unfortunately I wasn't able to simplify my current definition to a point where it could be used as an example, so please treat this more as an generic question.

Replies to This Discussion

Permalink Reply by David Rutten on February 8, 2015 at 10:29am

There isn't. The detection happens when a component (or parameter) is asked to solve itself, and it's currently already in the process of solving itself. This is a contradiction which (most likely) means a cyclical dependency. There's no way to bypass this for existing components, however plugins like Anemone and Hoopsnake get around it by implementing their own solution logic.

It is programmatically possible to send data to a parameter without having a wire, but it's difficult to achieve and it probably cannot be done during a solution.

Permalink Reply by Marc K. on February 8, 2015 at 10:46am

Thanks David for the quick and thorough response! Hopefully I didn't ridicule myself too much with this question, haha :)

I managed to get around this problem using multiple Hoopsnake components before, but as this approach brings my computer to a crawl, it simply couldn't be used for realtime applications - which is/was the point of this particular definition.

Thanks anyway!

Permalink Reply by nikos tzar on February 8, 2015 at 10:39am

Hi Mark,

Since you are already using hoopsnake, why not use it to avoid the cyclical data stream?

Anyway, there are also 2 "dirty" workarounds (that I know of):

http://www.grasshopper3d.com/forum/topics/is-there-a-cyclical-data

and

http://www.grasshopper3d.com/forum/topics/automate-the-data-dan?com...

Permalink Reply by Marc K. on February 8, 2015 at 11:06am

Thanks Nikos for the links! Those links appear to be very helpful...

Ad 1st workaround: I did find this thread before starting a new thread, but I haven't read it thoroughly enough and "ditched it" rather quickly - sorry!

Ad 2nd workaround: Data Dam slowly appears to be the "deus-ex machina" component of Grasshopper. Something isn't working? Data Dam to the rescue! :)

As for the Hoopsnake-approach, I suppose there would also be the possibility to route multiply data streams to a single Hoopsnake component but this would mean a little bit too much work for this kind of tinkering-around project.

Permalink Reply by Marc K. on February 8, 2015 at 1:52pm

Update: Data Dam workaround indeed works. Crazy. Will post some results later.

Permalink Reply by Marc K. on February 8, 2015 at 6:21pm

Just in case anyone wonders what I was trying to achieve:

(Best viewed in Fullscreen@1080p)

Data stream detection prevented me to check if the snake's head (point) is in the very same location as the food (point). Used the "Data Dam"-workaround (described here) to fix this problem.

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