what expression to get total number of attributes?

[Malcolm Zaloon]

Hi

 

 

How to get total number of attributes coming from "connectivity" node?

 

i wish to put a color ramp parameter and i need last value of range be the total number of "connected pieces" of connectivity found on geometry.

 

so, in my color ramp will be:

 

    range:  0 to <number of connected pieces found>

 

thanks in advance.

Edited March 31, 2014 by Malcolm Zaloon

[magneto]

You have to use AttribPromote SOP to promote the attribute to detail using Maximum mode, which will give you the number of connected pieces.

[iamyog]

If you promote your attribute (let's call it "number") as a detail with maximum as Promotion Method, you'll have the total of connection found minus 1 (since it starts counting at 0). You can then call this attribute via the detail expression :

detail(opinputpath(".",0),"number",0)+1

 

 

edit : magneto had been quicker

Edited March 31, 2014 by iamyog

[magneto]

Good catch on the +1

[Malcolm Zaloon]

hmmmm, i promote to detail with attribute promote node to maximum, and change new name to "total"

 

but i can´t get with $total on color node? it´s not working...

 

how i get the attribute total correctly?

 

thanks guys for fast reply!

[magneto]

You have to use the detail expression:

 

detail("../attribpromote1", "total", 0)

[Malcolm Zaloon]

thanks!

 

hmm, there is a way to turn into local variable? to be accessible with $total ?

[magneto]

You can but you have to do it manually. Unfortunately this is one of the things in Houdini that are not done automatically by every SOP that creates attributes. I think it's simple overlooks though as I can't imagine any noticeable overhead from adding a handful items to the varmap dictionary.

 

So now you either have to use AttribCreate to create the exact same attribute but turning off Write Values, or you can use addvariablename function in PointWrangle SOP.

 

I think there was something for this on Orbolt that's supposed to make it easier.

[Malcolm Zaloon]

wow.. to fast ... i´m newbie! heheheh

 

 

so my intuition is correct, the obvious is have a local variable accessible, on all nodes, right? so, developers need complete this task updating all nodes that not have this.. for a easier workflow...

i remember this lack on carve node, what is a big issue, so i need stamp every time i need a variation by id,prim,etc... why some nodes have this others no SESI?

 

 

and.. what is varmap dictionary?

[magneto]

I am not sure why they are overlooked because the variables are clearly part of the workflow. But if it was me, I would just remove all variable functionality and replace them with VEXpression style access. So you would just say @total inside any parameter and Houdini would know it.

 

Otherwise it feels too convoluted and micro-managed IMO, and creates another layer of indirection.

 

As for varmap, I might be wrong, but I think it's a dictionary that basically maps any string to any other string you want, so in your case, "total" to "TOTAL", but it could be anything.

 

The underlying data structure might be different, so SESI guys might need to comment on this

Edited March 31, 2014 by magneto

[Malcolm Zaloon]

I really think that diferent approach for diferent nodes and parts is really breaking workflow, and direct acess to variables need be enable in all nodes and places on Houdini to unify and standardize methods.

 

Houdini is fantastic, but this convoluted things are very annoying. its a MUST fix this thing for soon. say.. Houdini 13.1?

 

Thanks Magneto!