Hi to all,

I'm struggling with a first Houdini project. I have an irregular ground and need to extrude some faces to produce blocks of specific heights (attribute). But I need to flatten the faces that I extruded. I hope this screencopies will help you understand my meaning.

The terrain :


What I want to do with all the primitives :


So far, I end up with this to flatten the top :

But then I don't really know how to bring back the face to the right Y position.

I'm sure there are better ways to do it. Any idea ?

Thanks !

not sure if you want to flatten them INDIVIDUALLY or as a whole group.

for as a whole group, in Point SOP, I did the ‘Flatten Bottom’ preset. Just adapt to flatten top instead…(apply this preset to a torus so you get to see the effect first)

something like this:

set(self.x, min(self.y, ch('level') + getbbox_max(0).y), self.z)

Thanks a lot, Vusta ! Neat expression !
In order to do it individually, is the for-each primitive the solution ?

here you are…magic…

You're genius !! Thank you so much !! Problem solved

This worked great for me flattening the tops of OSM buildings, i projected the data onto my heightfield and needed to straighten the roofs, @Vusta's example worked fantastic, thanks for sharing your knowledge!

This was suuuuper helpful, thanks. I am not a programmer though and was wondering how I would do the same operation for the other axis' like for each side of a box? The code in the file provided works only for top and bottom. Thanks in advance!


Specifically, its this:

set(self.x,lerp(self,@opinput1_P,ch('amount')).y,self.z)

Im not sure how to make this work for other axis. I was hoping it was as easy as swapping the xyz location but its not, lol


edited: nvm I figured it out it was as easy as swapping

set(lerp(self,@opinput1_P,ch('amount')).x,self.y,self.z)

set(self.x,lerp(self,@opinput1_P,ch('amount')).y,self.z)

and

set(self.x,lerp(self,@opinput1_P,ch('amount')).y,self.z)