data persistence: storing input data from number sliders

Is there a way to store data values set by number sliders so that a single set of controls can be used for multiple "stations"? For example, I have sliders and knobs that define a curve for a boat hull cross-section and want to re-use these controls to define multiple "stations" (cross-sections at different X locations from bow to stern).

At present, I have to duplicate the controls for each station, which makes it clumsy to have an arbitrary number of stations.

I searched for "persistent data in Grasshopper" before asking this question but didn't find the issue expressed this way. Thanks.

Replies to This Discussion

Permalink Reply by David Rutten on May 18, 2015 at 10:03am

Solution -> Save State menu? I may have completely misunderstood though.

Permalink Reply by Joseph Oster on May 18, 2015 at 10:54am

That's an interesting feature, thanks, but unless I can save and restore state using Grasshopper components(?), it doesn't help.

What I want is the ability to define multiple curves in GH that are lofted to create a surface.

The two screen shots below show different control settings for a curve in the YZ plane (the 'Right' viewport) that determines a cross-section shape. I'd like to use the same single set of controls with an 'X' slider to define multiple curves/stations and then be able to access the curves to loft them to create a hull shape.

By the way, the 'Save State' feature gave me unexpected results... It wouldn't save the initial state (the semi-circle) from the .gh file but seemed to save the first mod after that? Also, the default state names (MM:DD:HH:MM) should include seconds to avoid duplicates (MM:DD:HH:MM:SS).

Thanks again.

Permalink Reply by Joseph Oster on May 18, 2015 at 11:29am

With no way to set slider values within GH, I guess what I'm asking for is impossible? Too bad.

I guess what I want is a 'Save State' GH component that would:

Accept any number of input sliders (knobs, Boolean toggles, buttons, etc.), the same way many components accept multiple "wires".
Save their values as a list (array) of 'states'.
Have an 'index' parameter to access each each 'state'. When the index value changes, the sliders would reset to previously saved values and any subsequent slider changes would automatically update the saved state for that index value.

Using multiple 'Save State' components would allow different groups of input sliders to each record multiple states. Sliders would be constrained to connect to only one 'Save State' component. There would need to be a way to purge/reset a 'Save State' component to empty.

Permalink Reply by David Rutten on May 18, 2015 at 12:01pm

It can't be done without some custom code component then. There are no standard components that modify the state of other components (other than Galapagos, which is not going to help you).

However it can be achieved with a small amount of C#/VB code and maybe a Value List to select the state you want. It would take more code to make a state saver, though that can also be done manually.

I'll see if I can come up with something before the lasagne is ready.

Permalink Reply by Joseph Oster on May 18, 2015 at 12:23pm

Hah! I'd rather not try to code in C#/VB but think a general purpose component like this could be very useful. Here is a mock-up - no output defined for the 'Save State' component as it would only effect its inputs. Not quite sure how the 'reset/purge' feature is triggered?

Thanks! I love GH/Rhino.

Permalink Reply by David Rutten on May 18, 2015 at 12:30pm

See attached. I hope the input is self-explanatory because I don't have time to explain it now (lasagne in 3 minutes!)

Attachments:

PresetRestore.gh, 10 KB

Permalink Reply by Joseph Oster on May 18, 2015 at 1:00pm

Whoa! I thought you were kidding!!

I got a couple of errors when I opened your file:

But the file opened anyway and seemed to work:

Choosing from the list of presets in the 'Value List' drop-down applies the appropriate param values to the sliders and knob, generating the different shapes. Impressive.

But the content of the "Presets" panel is entered by hand, not by using the sliders - right? So it doesn't really do what I need... I looked at your C# code and get what you're doing; I've been programming for many decades but not in C or VB and really don't want to go there now, myself.

Any chance of eventually getting a generic component, as described, for the rest of us? No hurry. Thanks very much.

Permalink Reply by David Rutten on May 18, 2015 at 3:05pm

Probably not, certainly not for GH1. I think a better state manager interface would be preferable for GH2, perhaps something which lives on the canvas rather than in the menu, so it can certainly work roughly like you describe.

It is possible to also generate the preset texts through code, it would be roughly the same amount of logic, basically just the inverse of what I wrote earlier.

Think a C# component which takes a single text field (preset name), an input where all relevant sliders and dials are connected, and a boolean SAVE input. It can then find a panel called "Presets" in the file and append a correct line of text to it representing the current state. You could even go nuts on the code and make the C# component pop up a state saving window, though that's probably a bit of a steep order without the cushioning IDE that is Visual Studio.

Permalink Reply by Joseph Oster on May 18, 2015 at 3:23pm

Well, on further reflection, this isn't nearly as "simple" as it seemed... My "spec" is close but to generate the set of curves for lofting, there needs to be a way to access the whole list of saved states collectively, as well as individually.

In other words, a list of 'X' values, a list of 'Beam' values, a list of 'Draft' values, etc.

Will have to ponder this further... Thanks again.

P.S. As a canvas component, it would be important to have 'Saved State' collect/save data only from the sliders/knobs connected to it - in effect, to mimic the checkbox toggles in the menu 'Save State' feature.

Permalink Reply by nikos tzar on May 19, 2015 at 7:35am

Hello Josheph, David,

The list of sliders' values for all sections could be created, using a [data recorder].

I put together an example file with simple rectangles as cross-sections.

Being a total noob at C# I didn't even try to mingle with David's script, so the sliders cannot be changed automatically, but if you set the X slider to a value where a section has already been created, you get a feedback of the X, Y and Z values for this section and you can also change them (by pressing the [create section] button again). You also get a panel that displays the X values of all available sections.

A major problem is that after closing the file, nothing is saved, so you would have to do this manually before exiting (internalize the created list inside a [Txt] container, or stream its contents to a .txt file through a panel, or something similar...)

Still, I believe that if you are familiar with C# you could merge the two definitions together and make it actually work as you want it to!

Permalink Reply by nikos tzar on May 19, 2015 at 7:35am

the file...

Attachments: