Houdini Tutorial - Stick Textures To Fluids

source files: timvanhelsdingen.com/sticking...
A little bit similar to another tutorial I did a while back, but from some posts I read some people still had some issues with sticking textures on fluids they were emitting and I thought i'd share an easier way to do so.
Howdini101:
timvanhelsdingen.com/howdini1...

[@trevorwilch460]

Man, been looking for a good tutorial for this but havent found it for free, was about to pay for it. Instead I'm gonna head over to you patreon. Thanks man 🔥

[@TimvanHelsdingen]

Thanks a lot man ^^ glad you liked it.

[@resilientpicture]

Awesome stuff Tim, thank you.

[@affectreflect]

Lovely stuff as always Tim.Thanks.

[@TimvanHelsdingen]

thanks dude! glad you liked it

[@philippwelsing9108]

Thanks so much, Tim! Icredible work. 🙌

[@rajeshmohanty91]

Feeling excited to do RnD on it, Thanks @Tim Helsdingen for this great tutorial which i have been waiting from decade....:)

[@TimvanHelsdingen]

glad it was helpful :D thanks for watching!

[@vipergx]

By the recommended videos and the JPOW video I cand easily spot a fellow WSB reader :D Thanks for the tutorial!

[@TimvanHelsdingen]

Haha busted! Yeah the jpow thing went viral on WSB initially. Glad you liked the tutotial!

[@StephaneSOUBIRAN]

Thank you for this tips !

[@TimvanHelsdingen]

You're welcome Stephane! Glad you liked it.

[@Damich]

Hi, I am using karma and I managed to do the triplanar projection but I didn't find the reference projection space type. Do you know about this in karma ?

[@IronMan-yg4qw]

can you make a video on an emitter spraying wet concrete on to an object, like shotcrete?

[@angosalvo5734]

Thanks for this. Is there to do something similar with VDBs converted from geometries. Basically I wanted to blend between some animated polygons so I thought the best way to do it with vdb to fake some liquid animation. Now it seems I need some UV on the result to add texture variation on it. Tried your other method but the seams and distortions were too much.

[@TimvanHelsdingen]

Did you watch the exgended version of the uv fluid? as that's the part that goes into how to get rid of those, that isn't included in the base one. So the one where we rebuilding the mesh inside the compiled foreach loop. A lot of people seemed to miss the fact that there's a extended version which was originally paid (but it's also on KZbin now)

[@angosalvo5734]

@@TimvanHelsdingen Yes I did thanks. Actually my problem seems to be the UV attribute transfer where it connects uv island borders even after splitting the vertices. For some reason it is failing.

[@albancontrepois]

can we have same result with realflow for c4d ?

[@attilakovacs8329]

Good work man ;)

[@TimvanHelsdingen]

thanks dude!

[@wouterdijkstra1657]

Is this in someway also possible when the sim is already cached?

[@TroubleShotVFX]

I just can't believe how insanely complicated it is to do literally anything in this program.

[@TimvanHelsdingen]

hahaha, well it’s just that you need to understand how the data moves. If the functionality doesn’t exist you can make it yourself instead of needing to rely exclusively on the developers to build you features

[@CamilloRealTime]

I feel your concern. I started a new project for a FLIP sim that I can use in a game engine and realised just how little I can do on my own in Houdini and how difficult this software is. I end up in a week of fulltime youtube/forum research to grasp basic understanding how I could tackle a project... then I fall into a rabbit hole comparing solutions that all have their caveat and follow-up problems. This stuff is hard.

[@DommageCollateral]

@@CamilloRealTime how do you want to export flip besides with vat?

[@CamilloRealTime]

@@DommageCollateral I ended up with an alembic file for UE5

[@dolphin4ik101]

Thank you so much!

[@TimvanHelsdingen]

You're welcome dude! glad it helped

[@sinsterz3586]

has anyone tried this with a flat/wave tank, im trying to create whirlpool that distorts in image along with the whirl pool but these methods arent working

[@SeunJubril]

THANK. YOU.

[@TimvanHelsdingen]

you're welcome!

[@cadudatoro4998]

Nice!!!

[@HappehLemons]

Is there any way to adjust the UVs once they're on the surface? This work well, but I can't seem to find a way to scale my texture or make my UVs more uniform in any way.

[@TimvanHelsdingen]

We're not using uv's for render, were using rest.

[@HappehLemons]

@@TimvanHelsdingen I see, because of that is there no way to scale or adjust textures on mesh? I've stuck a texture to my fluid but I wanted to scale it down and adjust it a bit once its on the surface but didn't seem like I could find a solution.

[@rubykickkick2057]

@@HappehLemons Hi try type v@uv = @rest * 0.5 ;

[@MBSJQ]

Yes dude 👍👍👍

[@workflowinmind]

Thanks!! Starting at 11:00

[@TimvanHelsdingen]

Haha yeah I'm trying to also explain some of the other stuff to make it a little more complete. Got feedback on other tutotials that sometimes I tend to skip over certain things so I'm trying to include some other more basic stuff as well now so more people can follow.

[@workflowinmind]

​@@TimvanHelsdingen 😛!! I much prefer a tutorial with too much information than not enough, you're perfectly right to do so. It's hard, especially with H, to know what the audience already knows.

[@workflowinmind]

Also side note, if you fluid is mainly horizontal you want to use v@uv = set(v@rest.x,v@rest.z,0); in order to project from Y

[@justhumanity3950]

plz tell me the music 0:01

[@paulvansommeren]

Hi Tim, how would you combine this with a flat projection to reveal an image? (Like Matt Taylor's "Flow")

[@TimvanHelsdingen]

Hey Paul, Not sure what your question is, I'm not familiar eith "Flow" by matt taylor. I'm trying to search for it but nothing comes up that looks like something you describe..

[@paulvansommeren]

@@TimvanHelsdingen instagram.com/p/B_xFBDCnBpz/ this one :)

[@paulvansommeren]

I'm thinking freezing the UVs with a timeshift at some point, but i'm not getting any smooth transitions to and from the frozen frame

[@TimvanHelsdingen]

@@paulvansommeren I think: Do sim first and make sure reseeding is off. Then timeshift on the frame you want tbe production to happen. Add uv on that frame on tbe points, then attributecopy that uv over to the rest of the points.

[@paulvansommeren]

@@TimvanHelsdingen Yeah that's exactly what I tried, but there seems to be no continuity except for the 'frozen' frame. I tried at 2am so I'll give it another go when rested haha

[@octoghost3470]

can you do this without using redshift? cause i was following along but got stuck when it came the the redshift stuff

[@TimvanHelsdingen]

That'll depend on your renderengine, as long as it supports triplanar with reference positions that'll work.

[@octoghost3470]

Tim van Helsdingen ok thank you. I’m new to Houdini. I’m using the apprentice version of it but Im not sure how many render engines are on it

[@octoghost3470]

@@TimvanHelsdingen i dont think the render engines on houndini apprentice support triplanar with positions :/

[@philippaps44]

how would you render this in an external program? i am trying to render in cinema 4d octane but the texture is fixed although it works fine in Houdini

[@TimvanHelsdingen]

rest positions should come through as vertex tags inside c4d which you should be able to use in some renderengines (like redshift) I don't know about octane but it'll probably also work there.

[@philippaps44]

@@TimvanHelsdingen So in Octane, at least the old version i have (3.07) there is no way as far as i understand. Also tried the process you show inside Houdini-Redshift for Cinema4d-Redshift, but its not working either although the rest attribute does come through. tried the triplanar method also. Could this be a bug?

[@TimvanHelsdingen]

@@philippaps44 3.07 is quite old though at this point. Custom attributes got introduced in the 2020 version in houdini so i assume that also applies to the other versions. Rest would be a custom attribute. Time to upgrade :P

[@philippaps44]

@@TimvanHelsdingen first of all thanks for replying man! you are awesome. So i fixed it in Redshift, i had to promote the uv from point to vertex before i export the alembic to cinema 4d. So the sim gets imported with a uv tag. So far it works, i hope i haven't missed anything

[@TimvanHelsdingen]

@@philippaps44 nice! glad you got it working.

[@9AFilms]

any suggestion for Karma H20

[@TimvanHelsdingen]

plug your rest primvar into the triplanar position

[@brandoncyoung]

The dual rest is useful if you want to limit the smeary uvs

[@TimvanHelsdingen]

Have you been able to get dual rest to work properly though? I haven't quite been able to get them to properly blend with the dual rest solver.

[@brandoncyoung]

@@TimvanHelsdingen yup i can post a file if you like

[@TimvanHelsdingen]

@@brandoncyoung oh yeah that would be very helpful!

[@emilioochoa6575]

@@brandoncyoung I Need it!

[@brandoncyoung]

@@TimvanHelsdingen www.dropbox.com/s/kehesiigrhx2a7k/FLIP_uv_dual_rest.hip?dl=0