can I use a custom attribute to drive a Mountain SOP

[Valent]

Hi,
for some reason, I can't use a custom integer attribute like (i@a=@Frame;) to drive offset(x) it a 'Mountain SOP' but if I assign @Frame it works just fine.
I also tried it in a 'Timeshift' node with the similar result.
Am I missing something?

q2.hipnc

[Martin47]

you are looking for the point() expression.

it returns the value of a point attribute.

http://www.sidefx.com/docs/houdini/expressions/point.html

 

Edited August 6, 2018 by Martin47
double comment

[Valent]

Thanks, it works like magic!)
But why in some cases I can use the only @a  and sometimes like, in this case, I have to use point() expression?

[AntoineSfx]

14 hours ago, Valent said:

Thanks, it works like magic!)
But why in some cases I can use the only @a  and sometimes like, in this case, I have to use point() expression?

This is expressions vs VEX.. Not a Houdini historian here, so I'd rather send you on this thread on sidefx.com :

https://www.sidefx.com/forum/topic/34896/

 

But the thing is, you're not going to drive the offset.x of the Mountain SOP *per primitive* like that. I'm not sure what you expect it to do.

The closest I can think of is to append a polyextrude after your primitive wrangle, and use that attribute to scale the extrude distance, in local control / distance scale.

Or if you want to go that way, I asked something related a few weeks ago,

If you reassemble (merge in the for loop) those primitives, your result won't be continuous any more, because from one adjacent prim to another, you not only vary x and y in the mountain itself, but yo also vary the "offset" parameter of the mountain, which leads to a different function really.. Maybe you could describe what you want to do in the first place. #xyproblem

 

 

Edited August 7, 2018 by AntoineSfx