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Everything posted by Farmfield

  1. Create multiple FEM over time?

    Just opened your scene and I'm pretty sure your issue is you are forcing interpenetration - in my experience, if you create intersecting meshes, the solver will allow that interpenetration from that point - and I might be completely wrong, but that's my experience.
  2. Create multiple FEM over time?

    If your DOP doesn't contain a SOP solver, you're doing something wrong. #thetruthisoutthere
  3. sticky effect

    Yeah, there's absolutely need for something either more clever or more sophisticated. I wonder how well it would work to actually set this up in FLIP using a combination of the surface tension and the strain (elasticity) micro solver - I fear it's one of those types of setups where it's easy to get stuck in tweaking hell trying to get it working/looking "right"...
  4. sticky effect

    It all depends what you wanna do, but just doing a quick, unsophisticated method in SOPs, here's one way to do it... And you could easily apply a wire solver sim in the middle instead of my faux gravity setup there... sticky.hiplc
  5. a bundle of fun houdini vids i've done

    The only thing I can complaint about is your logo has no legs to stand on! Great stuff. I really gotta do a couple of those dancer setups, I basically just pushed it aside and forgot about it...
  6. Affecting flip particles by pop force by speed.

    Oh, as for the question, you'd just use a POP wind and tick the VEXpressions thingie and use something like amp *= (length(@v) < XX ) ? ZZ : YY ; Where XX is the speed limit, the ZZ the multiplier of true and YY the multiplier when false. And the above is short form for this: if(length(@v) < XX ){ amp *= ZZ ; }else{ amp *= YY ; } And you can use a POP wrangle and create an attribute for particle speed which makes it simpler to check the spreadsheet for where the speed lies, easier to find the sweet spot for the limiter than using trial and error, perhaps.
  7. Affecting flip particles by pop force by speed.

    Myke is Myke Mendes. And I did this quick setup recently, just to illustrate how much more controllable it is just doing a custom force for something like this, you really have absolute control whereas using the curve force, one force of the setup can make another behave very differently just doing small changes - I'd rather have that control creating the force "manually". And yes, this is shamefully simplistic, but it's just to demonstrate how simple it is to set something like this up. https://drive.google.com/open?id=0B6IjWrRnlE0dazdCay1NeVBVNWs
  8. KS_Feather

    I'm only after your secrets, or rather your non-secrets, hehe... So that makes it an even better share. Greatly appreciated.
  9. KS_Feather

    Wow, just wow. A much appreciated share. Are the assets open so we can see how you set this up?
  10. POP Grains and RBDs mutual interaction

    Sadly I don't think you can do feedback with grains on bullet, I researched this myself a while back for a cloth feedback type effect using grain sheets, but I didn't get anywhere with it. That being said, you might be able to set something up using two different DOPs and doing a per time step "manual" interaction between the two sims - basically use the output on one sim as input for the other and that output as input for the first, and so on - though that can quickly become crazy computationally expensive. Either way, I used a very simplified version of this idea in this setup:
  11. Stranger things - Elastic wall effect?

    You can use Entagma's grains approach for this exact thing. Scene file in the description.
  12. Timewarp copy stamp problem

    No sweat, I've been helping out here way to little lately, gonna try to roam here more.
  13. Timewarp copy stamp problem

    For for loops and for each loops are really helpful at times, so it's good to get into those workflows. Here's a good example on how you can use for loops for iterative tasks...
  14. Timewarp copy stamp problem

    Yeah, the for loops work the same in H15.x as in H16 and using a for loop is now preferred as they are moving away from the copy stamp function with H16, so better get into the for loop setups as it's how this stuff is going to be done gowing forward. And you hadn't referenced the correct node in the detail expression. copy_in_forloop.hiplc
  15. Timewarp copy stamp problem

    Aah, ok, I thought you posted in different sections, that's pretty common - and pretty annoying. This was obviously a mistake then, so no sweat. And I hope my reply solves your issue. The stamping thing is becoming deprecated, it's going into for each loops now, so better get used to that workflow directly as the copy stamp node will likely be gone with the next Houdini release.
  16. Timewarp copy stamp problem

    Posted a reply in your other post - but please don't post multiple posts.
  17. Timewarp copy stamp problem

  18. Setting this up as a copy stamp for someone in the Houdini Facebook group asking how to use a time shift on objects copied to particles, yesterday, but I also tried to set it up with a for loop and ran into this issue. Seems, due to how the iterations are counted, the setup "breaks" after particles starts to get killed off and the number of iterations gets "stuck", looping, or how to describe it... I'm probably missing some obvious solution, but I'm kinda stuck - so posting it here for someone with a brain to figure it out. copy.stamp.forloop.hiplc
  19. Issue with timeshift in for-loop "stamp" workflow

    Aah, of course - as I said, I'm probably missing some obvious solution - I was completely into using the current iteration... Much appreciated. Oh, and if this is the first thing you've written here in three years, I will take public credit for provokating that response.
  20. Differential curve growth

    Well, you won't learn anything from me or anyone else setting it up for you, because you are at the wrong place in regard to how far you have come in Houdini. And not saying that to be rude, I just want you to have the best angle of improving your Houdini skills. So what you need to focus on is attributes and attribute transferring, because it's seriously the key to unlocking Houdini. Imo the best "mental approach" in Houdini is to look at it as there's only points (*) and whatever you need to do is about manipulating those points. You also need to think about what you need to manipulate the points. In this case we are working with particles, so any growth is movement and that's velocity. So you need to manipulate that. You do that either manipulating the actual velocity or adding a force. Force is basically additional velocity added over time. So what you'd need is a basic differential curve growth setup and a source for your influencing force. So for that source you need to generate velocities (if that's not already there, like it would be in another POP sim or FLIP). I haven't messed with the new ocean tools, though, so unsure if it generates surface direction vectors, but seeing the foam and such, I would guess it does and that's attribute values you can use for something like this. When you got the differential curve setup you want to advect and the directional vectors you need to do it (likely a velocity vector) you can just set it up in a SOP solver in the POP sim, object merge in the source of the velocities and just use an attribute transfer to pipe it into a custom attribute on the POP object and then you'd just use a POP wrangle to add that attribute data onto the current velocities, either adding them to your velocity or using the force attribute, adding it over time. And if none of this makes any sense, we're back to the first line in this post and you have a lot of more time to spend in SOPs getting to know and understand how Houdini works with attributes - because it will never be more straight forward than this in Houdini. This seriously is pretty basic stuff, hehe... (* unless they are voxels, but kinda the same approach, either way)
  21. Differential curve growth

    Sure, as it's a particle system, any force will work, like something as easy as transferring velocities from a FLIP simulation to the differential curve setup in a SOP solver or alike - but that being said, I would guess it's going to be tricky to control. This particular setup is very happy at one specific conjunction of values and there it behaves very predictable in both 2D and 3D, but pushing it in other directions it either just stops doing much or it starts to behave very erratically. But try it out and post the results in the thread.
  22. Resample curve by width/pscale

    Absolutely. The differential curve growth thread is a great example on that as well. And there's a lot more on this subject on the Houdini group at Facebook, in a way kinda sad the know how is so fragmented now, with the Facebook group and the Discord chat/community - forums are truly the best way to do this kinda thing, imo, as Wiki's are the best way to organize and present information - Facebook and Discord is more about the moment, not some great solution from 2 years ago, as I find at OD Force all the time.
  23. Resample curve by width/pscale

    Oh, that's really cool, Dave. That's truly my kinda hacktastic solution. And the Facebook thread on this generated talk about doing this in CHOPs, so hoping for a scene file on that today or tomorrow, then I'm gonna compile the solutions into a list and zip the files for download (or collect them in a single scene file) - always great to be able to look at a different solutions for a problem, see how different people approach it.
  24. Resample curve by width/pscale

    Yeah, I will put this down on paper and see if I can straighten out the relationship, and it's of course based on circumference divided by segments to get the polywire, but with my current solution, I need to resample the curve to fit the overall divisions first, then delete any other points than the segment ones - it's kinda messy, to say the least. I have a new idea for doing this using a carve in a for loop to generate the points fed into an add SOP to recreate the curve, much cleaner, but I'll dig into that tomorrow - at the earliest. And just to be clear, if I was in production and had this issue, I'd go for your setup in a second, but as it's more generic, playing around with problem solving (the kinda stuff in the scene files I usually post on Vimeo), so I really want to find something that's easy for ppl to wrap their head around.
  25. Resample curve by width/pscale

    Man, you are brilliant with VEX. Much appreciated. Here's the direction I went - no clue how I came up with it, my brain is just auto-piloting most of the time, it's more reaction that action - not even kidding. Now, there is a relation to be set up between the pscale, the resample segment amount and the fit min/max to get this working "right" - though so far I have no clue what that formula is, but I'm pretty sure it's there, somewhere... resample_squares.v1.1.hiplc