Jump to content

From SOP nodes into a single VOP - a learning process

Recommended Posts

Hi all!

My recent goal in Houdini learning is to try and approach things in the simplest/less expensive way and also the most procedural way possible... sometimes I think you can't have both but nonetheless I would like to try it!

What I want to do is apply several iterations of noise into an object. That is straightforward (but not implemented yet). What I'm having trouble with is that I want the noise to be applied more at the base of the object and less (or none) at the top.

I would like to be able to do it in VOPS, but as you can see in my example file, I hit a wall... I have certain questions on how to approach but no solution :(

In "normal" SOPS, I kind of get it to work with attributes and attribute transfer/blend but... there is no smooth transition! I either have lots of noise or no noise at all!

I have the file (displaceByColour - 1st approach I had with attributes) with sticky notes all over the place and channel referencing whenever I see it useful because at the end of the day, the goal is to learn and be able to do kind of a tool where you can control everything! That's why I would like to go more with the VOPS because I wouldn't need to have 2 objects, being one only used to have an attribute to transfer over... in my mind this could be done with the VOPS by simply looking at the point numbers and apply more or less noise as the number increases/decreases... or something!

Any help, hints or comments are helpful! I know there's more than one way to do it but if I'm looking at this wrong, please say so!



Link to comment
Share on other sites

Hi guys!

Thanks for a very fast reply! Both solutions work exactly like I want! Now I have 2 different ways to do the same thing, which is amazing!

I'll try and play with both your networks and pick different stuff from one or the other!


No problem in being 2 VOPS. To be honest I prefer to divide stuff into smaller chunks but that make the entire network far easier to read! I did use the colour to try and visually break/understand how to break and choose an area of effect but then in the Vopsop I totally ignored my own network... :(


Any particular reason for the transform node after the subD? You used it to offset the object in X and Y and of course it will impact on the max and min of Y but besides that I don't see any other changes (of course it impacts on how the noise will be calculated but...)

By the way guys, in SOPS how could I do the smooth transition?


Link to comment
Share on other sites

Hi Dobril!

You solution is spot on with what I was imagining it to be!

It's interesting to see that in the 3 solutions I was close but no cigar! But at least was thinking the way it should be!

Interesting to see both approaches of the use of a bounding box and I see the error "of my ways" with the negate I was using (and the position where I was negating the values!).


Will try to mix the 3 approaches to make one that you can also include extra controls, like a nice ramp for the noise and so on!

Cheers guys! You rock!

Link to comment
Share on other sites

Hi woodenduck!

I see! Also a very elegant and simple solution! Thanks!

It's really nice to see that as soon as you start thinking in terms of points/Vops so many of the things that were an issue before (like the transition in the noise - due to a group) fade away...

Link to comment
Share on other sites


there is some interesting answers around here !

@JSantos :

the reason to put this transform node was to show you that the vop system is independent from where you place your mesh.

no need to a paritcular Y position to make it to work.

  • Like 1
Link to comment
Share on other sites

Hi Vincent!

Yeap, lot's of nice answers and solutions!

yeah, I knew that Vops are independent, since they iterate over the points... you can position them anywhere and it still works! That's one of the main (probably biggest) reason why I wanted to change my SOP (attribute create/transfer) approach to a VOPSOP... because previously I needed extra geo, that geo had to be referenced and positioned correctly and so on...

Thanks for your feedback and the care you took!


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...