Is there a way to limit the current point number to used groups?

[magneto]

It's hard to word this but basically I am trying to assign weights to points based on their index. So point 0 will have a value of 0, and point N will have a value of 1.

I did this no problem but when a group is specified, I want the values to be adjusted accordingly. So if you have 100 points, and then created a group for point 25-50, then I want the range to be 0-1 based on 25-50, as if 25 was 0, and 50 was 100.

Basically I need something like:

group.startIndex

group.endIndex

Can I do this purely using nodes? I am using AttribCreate so if anyone has any solutions for this, I would appreciate it.

Thanks

[anim]

here is the example using attributecreate and a little python as a value expression

groupName = ch("group")
geo = hou.pwd().inputs()[0].geometry()
group = geo.findPointGroup(groupName)
points = group.points()
start = points[0].number()
end = points[-1].number()
return hou.hmath.fit( lvar("PT"), start, end, 0, 1 )

look in file how it's used

weight_group.hipnc

[sadhu]

Is this is what you want?

[sadhu]

Sorry. Forgot to attach the file.

weights_based_on_index.hipnc

Edited February 29, 2012 by sorry

[magneto]

Thanks guys, exactly what I needed

[magneto]

@anim:

I just tried using the same expression in a very similar case but it says "extra token in the expression". I don't understand.

Can you please take a look at it?

att.hipnc

[anim]

change expression language of that parameter to python

right-click/Expression/Change Language to Python

[magneto]

Wow I thought the global icon at the top corner changes all fields for the selected node.

So Houdini allows both languages in the same node instance?

I just did it and it worked. Thanks man, didn't know this.

[anim]

global icon is just for new expressions, otherwise you can always choose, expressions that are in different language than set by that icon are red, not green so you can tell straight away