Houdini Paint Splash Tutorial

In this tutorial I'll show how to create paint splashes that are easy to control with custom velocity fields generated by simple curves.
As usual the file is available on Gumroad. I've commented the file, extended the functionality of the velocity field system (adding the ability to paint areas of higher force). You'll also get some insight into the shading and rendering from the file.
gumroad.com/l/eZGnf
Also at the end of the video there's a preview of my next video where I'll show how to take this set up even further using some more advanced techniques using help I found on forums and using some tools that a couple fantastic Houdini users have created.
Check out whatifound.net for more and follow on Twitter and Vimeo for updates.
Thanks!
0:00 Intro
0:32 Curve build explanation
1:18 Build single curve
10:20 convert curve with v to vel volume
13:50 Creating Velocity Pump in DOPs
23:14 Extending the velocity from curve set up
25:55 Previewing sim results
26:55 brief @ramp explanation
29:22 Test Renders
31:13 Further adjusting the vel field
32:50 wrapping up
33:24 Preview of next video -- extending the set up with custom tools from more advanced users.

[@philippwelsing9108]

This is such good info for art directing particles and water. Thank you! Also, the rudeness of people COMPLAINING here - unbelievable. Putting in that much work only to be rudely commented by anonymous clowns from the internet. People really should watch their tone, be grateful and practice learning research. Jesus...

[@Lochie2007]

Just wanted to say thank you for your tutorial! I was able to create a stylised chocolate splash with your setup! Amazing!

[@ArgoBeats]

Great tutorial, very nice explanation even for us Houdini beginners, thank you very much, Jason!

[@benhall3995]

Bought the file to support. Excellent tutorial and the follow up for retiming was a lot of research. Thanks!

[@WhatIFound]

Thanks so much. I really do appreciate the support.

[@nykoo974]

This is awesome, Thank you Jason, keep the tuts/knowledge coming !

[@jasonharmon9538]

Thanks so much, I got slammed with work the past several months, I'm hoping to make more time to keep putting out content like this.

[@Helios.vfx.]

I'm just learning about fluids and this is mindblowing

[@littlad]

just started following this. looks really promising. A nice way to get the @v to follow the curve better, instead of converting @N and negating or complementing, what you could do is drop down a "reverse" sop, set it to either "reverse" or "reverse U" and then drop down your polyframe, set the tangent to "v" directly. So far, so good.

[@MrMarinest]

Really good! Simple and elegant! Thanks for that. Give us some more)

[@jluisroga]

Super tut! Very detailed and easy to understand . Thanks

[@WhatIFound]

Thanks so much, really appreciate it.

[@cgcg4505]

Thanks for taking the time, more content please!

[@WhatIFound]

Thanks! More content is definitely the plan.

[@geoffburns]

Greatest tutorial in the history of tutorials!

[@WhatIFound]

Thanks Geoff. That’s high praise. I was on a roll making these when work slowed down. I’m booked for two months on a job now, but still trying to squeeze in some videos on some of the stuff I’m using on this job.

[@geoffburns]

@@WhatIFound Never a bad thing being busy man. Just keep them coming, cause they really are awesome!

[@JuyongJeon]

Amazing tutorial, Thank you so much

[@harrykirby9488]

This really helped me out! Timecoding and good video quality really made it easy to understand so keep it up :)

[@WhatIFound]

Glad it helped!

[@ashy49592]

@@WhatIFound can you make blood splashes for unreal engine

[@massimobaita7178]

Thank You very much, Jason!

[@jasonharmon9538]

Glad you found it helpful, thanks.

[@evmlionel]

thanks for sharing! love it (:

[@WhatIFound]

Thanks for watching!

[@TheBratscin1]

You rock Jason

[@jasonharmon9538]

Thanks so much

[@StephaneSOUBIRAN]

Thank you !

[@jasonharmon9538]

You're welcome! Thanks for watching.

[@stinkylando]

How lost was everyone @ the 13:50 mark. Is there a separate video for the setup to the flip sim?

[@juancarlosgzrz]

Thanks

[@jacquesdelobel8667]

Very good tutorial. Why don't you set the tangent in the resample node?

[@hanshubert6675]

thank you for doing this! Still i got to say that this one was kind of frustrating to follow for a beginner. just by rebuilding what is on screen i could not get it to work after that "now draw the rest of the owl moment" at 13:30. i have no clue how the particle bed upstream of the dop was set up or what happens after the dop.

[@zerosixtwosix]

❤️❤️❤️

[@dzb868]

What's inside burst-pump-tut?! Double it up and deleted some nodes, but you cut all of that part from the video! The tutorial lacks of a crucial part, and all the comments are mentioning it... how? How did you make the burst_pump geometry?

[@jasonharmon9538]

Hey, thanks for the reply. I think I understand the section your talking about. This tutorial focuses on how to use Vel fields to control a Flip sim... it assumes that you know the basics of how to set up a Flip sim, and that's what has gotten cut out for the sake of time. If I started from scratch explaining all the basics of flip sims, the tutorial would be very very long. Again, the point of this is controlling Flip with vel fields with the goal of building a set up for directing the splashes. Perhaps at some point when I get some time I can go over the very basics of how to set up sims, but that wasn't the goal of this video.

[@dariosaquetti1194]

@@jasonharmon9538 It would be good to put it back as most of us won't now how to do it. XD. Better long and complete rather than saving a couple of minutes. But it looks promising even for @N people like us lol.

[@wethefamousfive]

This is exactly it. You don't have to explain why but right now some of us have no clue and in order to get your files on Gumroad it costs money. That makes this video pretty useless because I for one did not come here to understand all details, rather to have a hum how to produce liquid paint. Feels now like a click bait. Would have been more honest just to say that no all nodes are included and that you assume we will know. Just not very cool. Which is say because it's a great video and you explain really well. I gave you my like even. Still disappointed.

[@nicole-ruggiero]

You are very talented however I had a really hard time with this tutorial. Perhaps I am not advanced enough but I do wish you went into more details about how and why you connected things.

[@ujjwalparekh433]

Hi, awesome video. Just one thing, In the render here the colours don’t seem to be mixing with each other but in the other retime video you made, I can see they’re mixing. Did I miss a step?

[@WhatIFound]

No, I don't believe the colors would mix here. I'm not sure they did in the retime example either, but it's been a loooong time since I've made these tutorials and don't remember all the details off hand. That said, if you want the colors to mix over time, you'd need to apply the color (or the attribute you're using to map color) either inside the DOP network, or afterward in a solver and average the values together at each timestep.

[@pondoitsame927]

this is my kingdom ome

[@CarlWicker]

is it possible to mix the colours?

[@vex-studio]

why the vex code is not working in any way!!!?? like I tried to write in a deferent way but the normals are not inverted!!! even the velocity value are - I checked it in sopread shit but the notmals still not inverted

[@chp617]

At 24:00 how did you get the different heights (velocity) in the attribvop1?

[@WhatIFound]

In this example I've grouped the topmost point, then in the attribute vop I'm using noise to drive the Y position of those grouped points. In hindsight, a simpler way would be to just randomize the pscale on the grid before I copied the lines onto it.

[@121peppermint]

v doesn't pop up as an attribute in the vdb from particles... help!

[@jasonharmon9538]

it should pop up as long as you've defined it in the node above... the v_from_N step. In that step you're using the normal vector to define the velocity.

[@juliegrytsai7851]

@@jasonharmon9538 oh thank you so much for your quick response and for the amazing tutorial❣️

[@michaeldavids2407]

Why make a tutorial if you are going to skip important steps? It was really easy to follow and helpful up until that point :(

[@bradleyjohn8986]

dont you love it when the tutorial skips 50 steps