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Everything posted by Farmfield

  1. Animating along curves with UVs are one way, and the example files on cg-wiki are amazing, but I also love the sort shift point number thingie I've used in many setups, hehe - and I know it's stupid, but I just love it.
  2. Yeah, there's no need to go for POPs - and it all depends on what type of effect, how much control you want/need, etc... Here's a non simulated setup using find shortest path SOP.
  3. There is no deception used here, it's just quite simple, hehe... It's just a habit, rather than scattering a single point on a surface, I usually just use one off the surface, so a sort randomly and then delete everything except point 0. Here I sort by Y and then delete everything but the lowest one. So the bottom most point is there and I feed that into the POP. The convert line SOP converts every primitive to lines between it's connecting points. If I didn't delete the surface, the minpos function would ray the point to the surface, but here I just want the structure of the mesh for the particles to follow. And I didn't need the restlength, but I just didn't bother about unchecking it, doesn't have any influence at any point here accept eating a small amount of memory. And yes, the minpos function moves the point to the closest surface position of the target, in this case input two where I piped in the line structure of the half sphere. And finally the wrangle where I normalize velocity and multiply it by 0.1 to force a constant velocity of the particle - else its speed would be controlled by the noise function of the POP wind, with wouldn't be very fitting for particles representing some kind of information flow or alike. If you want different speeds for each particle, you could use something like multiplying the velocity with rand(@id).
  4. You could use a substructure for the possible routes for them to take, then you can have them behave half "free" and half controlled, so to speak. pop_ray_to_line.hiplc
  5. Resample curve by width/pscale

    Anyone know of a simple way to resample a curve by pscale/width attribute - or perhaps another way to space hulls in a sweep or alike by pscale/width so lower numbers will yield higher sampling..? And the idea is to get more square'ish quads for a setup like this, procedurally... resample.hiplc
  6. Resample curve by width/pscale

    Funny enough, this was again asked in the Houdini Artists Facebook group and I had completely forgot about asking this back in April... Either way, here's two other SOP based solutions to this problem, the second one a bit of a joke, of course - though I have no doubt that method can be useful for some things as well... v1: https://drive.google.com/open?id=1mjJd0vd9KUSFW79ksRc5fioeMxXnu6Bu v2: https://drive.google.com/open?id=1mjJd0vd9KUSFW79ksRc5fioeMxXnu6Bu
  7. Differential curve growth

    Just wanted to post this as an example of using this technique as foundation for something else. Scene file in the Vimeo description.
  8. N-body via SOP solver with OpenCL

    Upped both scatters to 100k points and it still sim'ed 300 frames in about 2 minutes - just crazy. Very cool.
  9. Bullet: Activate on Collisions or Start Sleeping

    I have no clue what this was about, though - that was 13 months ago, I gotta download and check the file.
  10. Create multiple FEM over time?

    I was so close doing a wrangle when I remembered - there's wheels already, no need to reinvent one.
  11. Create multiple FEM over time?

    With a copy stamp, random vector per point (per frame) would solve it.
  12. Pyro Jet Exhaust

    No prob's, I've been bad at helping out here for a while, trying to get better though. And I have a lot of scene files like this posted on my Vimeo feed, lots of "tricks" and smaller techniques I stumbled onto, doing RnD, etc, so that's also something to check out if you're into getting to know Houdini...
  13. Pyro Jet Exhaust

    Yeah, then you got full control over the flame itself. Now I didn't do research last I did this or now, but if I was asked to do this in production, I'd do some proper research into how the patterning inside works, how the size and frequency of those patterns change with the burn rate, how the flame density and temperature drives coloring, etc - here I just faked the sh!t out of the look, hehe... And note that this is not the setup I used for the Fusion setup - that I did inside Fusion - but it was basically the same setup as this one. Also, this is just the mesh, for the shading I'd convert the elements to volumes and create a set of custom volume attributes to drive the shader density, coloring, etc... exhaust_flame.hiplc
  14. Pyro Jet Exhaust

    Creating flame and gas/exhaust as the same object might not be the best approach, it all depends. For a rocked or a jet exhaust, it's likely I would personally split it into one volume - as in non simulated volume - for the flame itself and then create a separate fire/smoke effect on top of that for the secondary effects from that flame. Now, there's probably situations where it would make sense doing a real flame in Pyro, though I haven't run into that kinda need so far. This is all made in Fusion but the principle kinda is the same, the exhaust is a particle system, but the flame itself was a 3D model...
  15. RBD's slowly sinking into yoghurt Flip Sim

    Use two DOPs, one for thew FLIP and one for the Bullet, and create the interaction manually. Check my bullet to FLIP setup here for some ideas on how to set something like that up.
  16. Multiple Solver Interactions

    Well, you got the scene files linked, just dig into it.
  17. Multiple Solver Interactions

    I've been messing with faux soft bodies using Bullet constraints just to get around the interaction stuff... But you can also stack DOP's and create interaction that way - though this will of course get computationally expensive, quickly...
  18. Create multiple FEM over time?

  19. Create multiple FEM over time?

    Well, personally I don't work like this, or at least not in production, it's like, well, this doesn't work, and you move on, hehe, find what does... So stuff that doesn't work is a bit of a non issue, if you get why I mean. I don't allow myself to get stuck fighting windmills, so to speak. FEM to me is for FEM only stuff and if it starts to cause issues, I just move on, because as I said, it's a solver that doesn't play nice (or at all) with other solvers. And I've used grains a lot, it's awesome because they are POPs, and FLIP and Bullet are point based as well, so all the POP stuff us available as well as you can do anything with it in a SOP solver. Oh, and though there are SESI staff running here, it's more likely to get them into s thread in the SESI forum than here.
  20. Create multiple FEM over time?

    No, doesn't seem like you can, or at least not easily - as in, messing about inside the DOP solid object- and finite element solver subnets. So grains is the more controllable choose here.
  21. Create multiple FEM over time?

    But even here, you get to a point where it breaks. You can up the steps, and that will of course help, but still, there will always be some point where it breaks again.
  22. Create multiple FEM over time?

    Naeh dude, this is all in H13.5... This one: [link] Edit: ^the link is for 16.0.633, latest production build, I just wrote 13.5 to confuse PS a bit more - it's friday, I deserve some entertainment, right?
  23. Create multiple FEM over time?

    The timestep is 0.25, the DOP substeps are 1 and the solver substeps 2 and collision substeps 2, and it works great for me. (the green stuff are encoding errors from imgur) flask.v1.Odforce.FF.hiplc
  24. Create multiple FEM over time?

    Time to submit this ticket? //SideFX Software Inc//Bug report//2017-16-09//Houdini 16.0.600//Softbody simulations doesn't calculate correctly if the software is run south of the equator// And my personally status is of course Alpha = 1.0
  25. Create multiple FEM over time?

    I'm digging into it now, but to be honest, I wouldn't use this solver because you don't have access to anything on SOP level (as in a SOP solver in DOPs) so my normal workflows are out the window - thus F it, not using that crap if I can avoid it. The whole point is control, imo, and seems you don't have any in regard to FEM... And yeah, long time since I dug into FEM, but it's annoying the crap out of me, it's not a black box, but it feels like it could as well be if I need to start unlocking the subnets in DOPs and start messing inside them - something that in itself seems to make Houdini extremely crash prone... Did I say I was annoyed? Grrrrrr...