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Posts posted by Farmfield

  1. This just gotta have a simple solution, just couldn't think of a straightforward way to solve it. I'm looking for a division independent way to group N amount of random points from the bottom (P.y == 0) and an equal amount of random points from the rest (@P.y > 0). And sure, you can solve this several ways, using a couple of SOPs, but I'm looking for something like a single expression in a group- or wrangle SOP, if that's even possible. 

    The only one-node-solution I can think of is splitting the bottom and other points into arrays in a wrangle SOP and choose N amount of points from each - but I instinctively feel there's gotta be a really simple solution I'm missing, it's my default mode, missing the obvious... :D


  2. Oh, that was a smart workaround, mess with the timescale - great tip. Lowering the speed/acceleration was the first things I did, then lower the stiffness, increase drag and disable gravity. But the timescale basically does the same thing in one setting. Very clever Alvaro. :)

    • Like 1

  3. Still very difficult to replicate the behaviour in Pflow, though - but I remember it didn't translate well using Thinking Particles either. But I might try setting this up with bullet and constraints and see what you can get. The great part with packed primitives is, they are points, so instead of unpacking them after the sim, you can simply delete all the packed primitive related attributes and use them as points together with the point deform SOP.

    And funny, even with all the control in Houdini, I still miss the TP workflow, it's just so easy to "organize" the particles using rules. Sure, you can do that in POPs using streams, but it just isn't as straightforward as the TP workflow. And note it was 2+ years since I did anything in TP, so this is a pretty persistent feeling. ;)


    Here's William Wallace's tutorial and the "look" is just over 20 minutes in. [link]

    I might try constraining particles to their original height, or have a higher drag in Y than X/Z, that should make them bulge more outwards.

    Alvaro, aside from disabling gravity and upping drag, lower the constraint stiffness to keep the particles from "springing back", thus keeping the rip shape - if you hadn't figured that out already. :D

    • Like 1

  4. That's not a pure gas fluid simulation - I would guess it's either a high res PBD (like grains) or a tweaked PhysBam FLIP sim (to get it sand-looking) using an air field (for that jaggedy breakup), with a Plume fluid sim on top. 

    Or I'm completely wrong and it was done using the 3D tools in the upcoming release of MS Paint. :D

  5. I would propose that's fairly obvious looking only 15 seconds into the promo video there's a wrangle with a for loop - even not being able to identify that as a for loop, well, that's in itself pretty telling it's not gonna be very light learning. Now, to be honest, it's not overly complicated stuff either (jump into the FLIP fluid solver subnet for a relevant comparison) and that's good to know as this is the kinda stuff you're getting into, learning Houdini - you're gonna need some dedication and put a lot of time into it, if you're serious about getting into this app. :)


    • Like 1

  6. Really cool.

    And there's a thousand ways to set this kinda thing up, there really is no right or wrong, the only thing I can add from experience is, keeping it as simple as possible will make it easier to tweak - though spending to much time to simplify something takes away from the time you have to tweak it - so it's a balance.

    Personally, though of course depending on how much interaction is needed, I would likely set a sim as yours up as two completely separate sims, one for the cloth, make that look like I (or the client) want it too, then do the particle disintegration - but if you have a setup with a lot (or obvious-) self collisions, there might be need to set it up to sim simultaneously - but even then, in my experience stuff like this is easier to control if run in two different DOPs and doing the interactive parts in a SOP solver in one (or both) of the DOP networks.

    As an example on how I often work, this is set up using two different DOP networks running in parallel with two way interaction - or faux 2 way interaction, perhaps (?) - and you got the link to the scene file in the description... :)


    • Like 1

  7. Creating age is simple, you can do that in a SOP solver in DOPs using a wrangle and @age += @TimeInc;

    And you gotta stop thinking about this stuff as bullet or cloth, there's only particles, prims, etc, the behaviour as particles, cloth, RBD objects are calculated in the solver - but it's all the same stuff. :)

    That being said, not sure why you would want age on an object unless it has a birth and death - like a particle might have - because an object which exists throughout the sim, it's age is the time.

  8. Hehe, looking through your setup, I can't really determine what you're trying to do, but if this is about controlling fragments as if they were particles, you can do that directly using POP forces with packed prims using the RigidBodySolver. :)


    I couldn't find the scene file for the setup in the gif above, but it was setup like in the scene file below. :) 


    • Like 3

  9. 19 minutes ago, pusat said:

    Don't skip if you think it's not for fx tds, as SOPs are at the core of every Houdini artist IMO.

    ^ absolutely agree! Whatever you do, it starts and ends in SOPs.

    Well, mostly, at least! :D

    • Like 2

  10. Hehe, naeh, that I know how to do. ;)

    The thing is, I got this really nifty setup I created for a growing (non fracturing) crack and fracturing combination-solution thingy - and I have it up and running - the only thing I need to make the setup "perfect" is an easy solution to this issue. So yeah, I need something like cutting planes in 3ds Max - but I think VDB fracture is the only equivalent in Houdini.

    F#{K, this is what I get for wanting to uncomplicate things as much as possible and run into something not really easy (or possible, even) to uncomplicate... And the setup I'm working on is similar to the one below (scene file in the Vimeo description), though tweaked for doing a growing crack setup with additional fracturing - and it's a kinda cool setup as a post process on a sim'ed RBD, so that gives you some nifty options for tweaking the initial behavior of a crack/fracture setup, but last, after the sim. 


    • Like 1

  11. So I have a pretty cool setup for creating a growing crack in combination with fracturing, but to make it work (as I want it too - or rather, as simply as I want the setup) I need a simple way to fracture a mesh from a curve on it - like extruding the curve and using that as a cutting plane. What's the simplest setup you can do to achieve that? And I of course mean other than using VDB fracture. ;) 




  12. I'm pretty sure the wire SOP applies it's own UV mapping and that might be what's throwing it off..?

    And I think the lack of response is about you not posting a scene file, from what you've said so far, it's a bit of a guessing game what is going on in the scene. If you have stuff you don't want to share, you can work around that by using a null at the end of the setup, though before the wore node, then right click and lock it - then you can delete anything accept for the last part and the shaders, so we at least have something to go on, troubleshooting this thing. :)

  13. I might have been mistaken - Jenny did not expressly state it wasn't allowed, se phrased it like this...


    > > Your Houdini-Indie license is for 1 machine, it will not work on 2
    > > machines at the same time. You are permitted to move the license to a
    > > different machine 3x per year. Also, the Houdini-Indie license is a
    > > node-locked/workstation license. It can only be used on the machine it is
    > > installed upon. It can not be accessed over a network from a remote
    > machine.
    > >
    > > Houdini licenses see a dual-boot machine as 2 machines, and your
    > > Houdini-Indie license will only work on 1 boot.
    > >
    > > If you need to use Houdini on both machines I suggest that you install
    > the
    > > free Houdini-Apprentice on the secondary machine. You can use our online
    > > conversion tool to convert the Apprentice (.hipnc) files back to Indie
    > > (.hiplc) format.

    So yeah, it might be a purely technical issue - sorry, I had interpreted that erroneously. :P

  14. I can say one thing, it's not allowed - I actually checked this with Jenny at SESI just 2 weeks ago, having built my new workstation, my idea was to primarily run Linux and have a dual boot with Windows for some stuff - but due to this I had to skip Linux - for now. I'm buying an additional Indie license soon anyway , so I can solve it with 2 licenses...

  15. Replicating TP's volume breaker in Houdini - without it becoming very heavy - is tricky, to say the least. I haven't dug into it that deep, but the tests I've done with recursive fracturing so far has turned out very, very heavy, pretty quickly. TP's volume breaker is ridiculously efficient.

    So yeah, as much as I love Houdini and I have no interest whatsoever to go back to Max, I miss TP, damn, I miss it. 

    • Like 1