Using the hscript chop() command, I can pull the values from channels in my chopnet, eg to pull from the channel 'mydist0'

Trying to do the same thing in vex and iterate over every channel (mydist0, mydist1, mydist2 etc) and it always returns 0.0.


I am not entirely sure what the 'Sample' argument should be as the docs aren't very clear. I assume this is what I'm messing up?
https://www.sidefx.com/docs/houdini/vex/functions/chop.html [www.sidefx.com]

I think you need to use op: syntax
Where sample is the fractional sample of your chop channel
So using @Frame instead may not be exactly the same, but can be close if your sampling rate is the same as fps, then it'll be just off by 1 as samples start from 0 and frames from 1

Thanks Tamte - where/how would I find the sampling rate that my chopnet is using?

EDIT: Found it - Samples/sec is MMB click info. So in this case I would use @Frame/24 ?

Hamilton Meathouse
EDIT: Found it - Samples/sec is MMB click info. So in this case I would use @Frame/24 ?

If your sampling rate is 24 samples/s and frame rate 24 fps, then you would just use @Frame-1

Hmmm. @Frame-1 returns 0 no matter what frame I'm on.
@Frame/24 returns 67.31 on every single frame (which is weird, as the chop channel it is pulling from increases every frame. I'll need to try a simple repro to upload

did use the op: syntax as mentioned?
as that was the main reason of it not working, the @Frame vs @Frame -1 was just a tiny technicality to point out that frames and samples in chops are not the same

here is a simple file

Yep I have that correct - but as I said, using @Frame-1 or @Frame returns a constant value of 0 across all frames. If I use @Frame/24, I get a constant value of 66.86 across all frames

Hamilton Meathouse
Yep I have that correct - but as I said, using @Frame-1 or @Frame returns a constant value of 0 across all frames. If I use @Frame/24, I get a constant value of 66.86 across all frames

you may need to post a simple file then

did the file I posted work for you or do you see the same issue?

Ok, works fine in sops, but doing it inside a point instancer in LOPs it does not seem to like.

Does it work if you use a full path to the chopnet rather than a relative path?