Hi,

I have dozens of noise nodes that I need to change the values of the noise for but want to use a variable instead of hard coding the values and also use hscript to set them (instead of doing it manually).

Essentially I want to do something like this:
opparm subnet1/noise4d1 amp ($noise_x $noise_y $noise_z)

But of course the variable value gets evaluated in this form but I want to insert the string (i.e. “$noise_x”) into the fields but can't figure out the correct syntax. I've tried various forms using single and double qoutes, no luck.

Any suggestions?

Thanks!


–Mark

You can use
“\” to comment out the $
opparm subnet1/noise4d1 amp (\$noise_x \$noise_y \$noise_z)

if you want an expression into a field…in this case you may want to use chadd and chkey…
set cosvar=cos\(\$F*ch\(\“../blender/freq\”))*ch\(\“../blender/amp\”)+ch\(\“../blender/offset\”)

set sinvar=sin\(\$F*ch\(\“../blender/freq\”))*ch\(\“../blender/amp\”)+ch\(\“../blender/offset\”)

chadd -t 0 0 0 $SOP tx
chadd -t 0 0 0 $SOP tz
chkey -t 0 -v 0 -m 0 -A 0 -F “$cosvar” text1/tx
chkey -t 0 -v 0 -m 0 -A 0 -F “$sinvar” text1/tz

Hi,

OK. Thanks for the tips, will try them in a bit. I thought I had tried to escape the ‘$’ char with a ‘\’ but maybe I missed something.

Thanks!


–Mark

I'm pretty sure you want the chadd/chkey approach - by entering an expression into a field, that's actually what you're doing behind the scenes. I don't know the precise param names, but something like:

chadd -t 0 0 0 subnet/noise4d*/ampx

chkey -t 0 -v 0 -m 0 -A 0 -F subnet/noise4d*/ampx $noise_x

Something like that, anyway. Do an opscript on the op to double check.

Cheers,

J.C.

Personally, I'd skip the variables and just add spare channels to the operator where the noise is being applied (point SOP?) That way, you have a basic UI right there, you get some sliders, labeled parameters, etc. And if you have the same settings in multiple places, you can always create the parameters as spare channels up one level, or just have a null SOP that provides the channels to which all the other SOPs point.

– Antoine

JColdrick
chadd -t 0 0 0 subnet/noise4d*/ampx

chkey -t 0 -v 0 -m 0 -A 0 -F subnet/noise4d*/ampx $noise_x

Hi there JC,

Thanks for the tip, turns out that Houdini wouldn't create any channels at all, I restarted H and then it was working fine. Weird. More than likely operator error. :-)


–Mark

Antoine Durr
Personally, I'd skip the variables and just add spare channels to the operator where the noise is being applied (point SOP?) That way, you have a basic UI right there, you get some sliders, labeled parameters, etc. And if you have the same settings in multiple places, you can always create the parameters as spare channels up one level, or just have a null SOP that provides the channels to which all the other SOPs point.

– Antoine

Hi Antoine,

You know, I started by using spare channels then realized I needed to do this at a “global” level, thus the variable usage. But now that you mention it, it would a lot easier to put the spare channel and controls at a higher level in the network. Much better.

Thanks for jogging my synaptic net mess!


–Mark

I know this post is way old, but just ran into this on H8 myself,
when in H9+ you can opparm the variable as a literal string w/
single quotes.

# H9> opparm /obj/model tx ( ‘$VER’ )
# H8> chadd /obj/model rx ry rz
# > chkey -t 0 -F ‘$VER’ /obj/model/rx /obj/model/ry