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Found 443 results

  1. Hi guys! I would like to share here my latest personal project. Everything done in Houdini and Mantra Hope you like it. Youtube Version: Shark_Youtube.mp4
  2. Flip PopCollisionIgnore?

    I am messing around with some FLIP collision effects and have found the popcollisionignore node doesn't work with FLIP sims. I'm confused on why exactly it doesn't considering its operating on the geometry, is this a problem/setting with the FLIP solver itself? It obviously works very easily with a regular pop sim but no dice otherwise. My plan here is to shoot the particles into an object, once the particles are inside the object it switches to collide with the object, and the particles are stuck to swirl inside of it. This would all work fine with a sop solver and some group nodes if the popcollisionignore worked as intended, can someone maybe point me in the right direction? Thanks! flip_collision_ignore.hipnc
  3. HEllo, This is my first question here. I've searching in the forum without success. I have some water wich follow a spline. I do this with Flip fluid and a popCurveForce. Now, this water is supposed to have some very visible Molecules inside . 2 or 3 types of molecules. I have try by scaterring point inside the fluid surface and then using CopyStamp. But the molecules ( pink Pigs here in the second screen capture ) are not flowing nicely with water . They just appear randomly inside water, to bad .. Idea #1 , i need to select some Flip fluid particle when they born to link and constrain a new pig on it. Idea #2 , i need to create another particle system with pigs, wich use the flip fluid sim of the water as velocity maybe ? Can you help me ?
  4. Hello! So I just started dabbling in FLIP and have a little river scene everything looks decent except for the whitewater. It takes forever to cache but I have the rasterized particles cached out and the standard particles will be finished caching later this evening. I've played with the spray shader but it looks kind of weird when applied to the rasterized particles, especially with the noise parameter that's [on] by default. I also read a few posts that suggested trying a billowy smoke shader instead. That made it look much better but still not correct so I figured I needed the regular particles cached in addition to the rasterized ones. If that's so they're caching now, but when they're finished what do I do with them? Last time I had whitewater particles cached they just rendered as spheres because of the pscale, am I supposed to mesh them like the FLIP and then layer them? I can post some screenshots once my cache has finished.
  5. Hello I'm trying to create a quasi-ribbon type spine setup with sops. I've got two Null controllers that drive position and orientation using quaternions. The orientation is derived using vectors from points in the null controllers. I then used a mix in a vop to blend the orientations to get almost good twisting in the spine. The problem arises when I rotate past a certain amount the orientation flips. I think it's a quaternion thing, Maya does this all the time. Is there a better way to create this kind of setup with no flippen flipping? In the hip you'll see that I'm animating only the top controls Y rotation and when goes just passed 236 it flips. Any help would be super appreciated. Kev dynamic_spine_03.hipnc spineFlip.mp4
  6. Hey magicians, I'm getting crazy here. I have a FLIP setup wich I did a compress cache, when I jump into white water it works fine. I send the setup to my client, he run the sim for compress cache, but for white water he is getting only in the waterfall and not the river. I think it has to be with some groups. Here's an image to illustrate the issue When I go to "White wate source > Out" the ww shows ok for both mine and client, but in white water import I get this, any tips to fix this? I can't make him run the sim again since we are almost in the deadline. Thanks
  7. Bending control

    A few months ago I was watching “Avatar, the last air bender” for like 5ft time and wanted to create some bending control, I'm still working on the water bending, so here's a WIP from this weekedn. Right now there's only to WIP, but will keep on with this until I master the 4 elements! https://vimeo.com/286783260 [vimeo.com] https://vimeo.com/272510944 [vimeo.com]
  8. Packed RBD Objects and Flip Explodes

    I'm trying to create cheerios falling into milk. I did a test with 2 toruses falling into a flip sim. If the toruses are separate RBD hero objects, then the sim works fine. https://drive.google.com/open?id=1Z98WekxuaIQ89vmxReqRHTgWjxgkuPUX [drive.google.com] However, if I try using packed RBD objects, then the sim explodes. https://drive.google.com/open?id=13U4Su0a3iVEpLx38lEuWxpORUdciKZCP [drive.google.com] I tried reducing the flip solver interaction scale from 1 to 0.5, but that didn't help. Do packed rbd objects interact correctly with flip correctly in houdini 16.5? What am I missing? thanks Torus2PackedRBD_FlipExplodes.v011.hipnc
  9. smaller ripples

    Hi guys, I have a flip simulations where I am dropping a rock in a vase. I would like to keep the velocity of the splash it generates, but I would like to decrease the amplitude of the waves that the flip sim creates. I've tried to play with the velocity smoothing, but it will also decrease my splash highness. any suggestions? maybe it's worth doing it post sim? thanks a lot
  10. Hey Magicians!, I've got a flip tank and I need a splash from a object that collides on the side of the wall, how can I get this effect? so far I faked by making 2 sims and merging but there's probably a better way to do this. I need to have the boundaries closed on the flip so I don't get "air" on the sim. This is the result that I get with the closed container and it needs that outer splash Any tip will be great! thanks!
  11. Flip fluid forces

    Hello, I'm new to houdini and I'm building a watersim which creates a wave. At the moment I'm using a box as a pusher and a initial velocity to push the fluids in the opposite direction. But I'm looking for a way to only move the water below the surface. Maybe some sort of box in which the fluids below the surface are pushed towards the pusher. Does anyone know a easy way to achieve this? Thx! Wave_v05.hipnc
  12. Houdini ocean explosions

    Hey guys, I'm pretty new to Houdini. But I'm looking to create an ocean explosions almost like a bomb going off under water. I have a flip tank and an deforming mesh that replicates the exspolsion, however I cant seem to have the mesh interact with the flip at all. I'm sure I'm doing this very wrong so hopes you guys can help Cheers ocean_explosions.hipnc
  13. guided ocean from animated geometry

    Hello this question was originally asked here (and I have pretty much the same question) https://www.sidefx.com/forum/topic/46028/ "I am wondering if it's possible to simulate a thin layer of ocean from any given geometry mesh in houdini?" Or from my input mesh that is a deforming animated plane? It is basically wave previs anim from Maya -- I am looking to drive a flip sim with this animation similarly to bifrost guided parameters: In the sidefx forum I linked someone mentioned "- detect position of flip particle if it is below or above the surface if below the surface but the distance with the surface is below a certain threshold advect it by the point velocity. if the distance is more than the treshold it get deleted every frame." I was wondering if someone can headstart me with how to go about this implementation, does this process need to be done within the solver? Thank you all for your time! -Shane
  14. Hello magicians, I'm working on a large scale FLIP scene and need some tips regarding to workflow. The main scene has 2 FLIP sims, 1 for a waterfall, and 1 for a river. On my current setup I made the river using narrow band, and the waterfall using a emitter, not sure if this is the best workflow in terms of speed and direction, the current setup looks like this (blue = waterfall / red = river) And here is a viewport sample Questions: 1) Is this the best approach for mixing a waterfall with a river? emitter + narrow band? 2) I saw in other post that some people breaks the geometry in equal modules and then put them together, should I break the river within 3 equal parts to save time and quality? 3) I readed that when you export particles, is useful to delete attributes that won't be used, I did a quick test with all attributes and 1 frame was 800mb, deleted some and took it to 200mb, is this a right approach? 4) For final meshing, should I create VDB / polygon soup and export passes in order to make detail stuff like foam? 5) Should I export particles in wedges? 6) There is a dop workflow to upres particle/flip mesh like "gasupres" within pyro? Would love to hear any tips regarding to large scale flip, will keep reading on the forum in the meantime Thanks!
  15. flip particles follow the surface

    Hello everyone! I have a question that is how to make the flip particles follow the surface flow.look like this viedo.
  16. Hey magicians, I'm working on a flip river wich I need to have color attribute, followed H16 Flip Masterclass and get there, but then I tried to add color in several ways but I can't get it working. I tried adding a sop solver to dops with attribute transfer, but the color didnt worked on the motion. Also tried making source volume with points from volume with uv texture but velocity gets weird. Working river without CD Cd particles with weird velocity Any tips on how to fix this? attaching a hip. Thanks in advance flip_issue.hip
  17. Color in FLIP sims - milk pour into tea

    Hi everyone, I was thinking of creating a simulation of milk pouring into tea as a showreel piece, but I'm not sure how best to go about it. I have seen people using color in FLIP sims, however in all the examples I have seen, the fluid is shaded to be opaque (like different color paints mixing). In my case though, I'd need to be able to see the milk as it is poured into the tea and see it underneath the surface. Then over time, it needs to change the color of the tea. My best guess would be to simulate the liquid, and then create a separate smoke simulation for under the surface of the water. However I have no idea how I would integrate the two. Here is a reference video I found: Any ideas for this would really be appreciated!
  18. Flip Splash - Grid Scale Optimisation

    I'm doing a flip sim of a splash. My particle separation is 0.006 which produces 14mil particles so pretty low. However because its quite a big splash the bounding box of the sim gets quite large so by the end of the sim I have 600mil voxels in the surface volume and 115mil voxels in the vel volume. So this is crashing my machine (which has 128GB ram)... My grid scale is the default of 2 but the vast majority of those voxels will be wasted since there are no particles in most of the bounding box. Is there any way to optimise this? The obvious way would be to use sparse volumes in dynamics instead of Houdini's native volumes but I imagine that would be creating a flip solver from scratch.. Or can I increase the grid scale without it negatively affecting the sim too much (i'm going to test this now..) I've attached a flip book of the sim https://drive.google.com/open?id=1k3Kexf-DJ5_ULPLt6dpsfx5f9LtW2OVz
  19. waterman

    Hey guys!I want to make a waterman by houdini , Can you give me some advice? look like this one:
  20. Hi everyone just a QQ, I'm playing with some variable viscosity on a fluid sim. I have a simple object (torus) that i've added some aa noise to to drive the viscosity, that's all fine but when i run the sim and the fluid drops to the floor the noise texture doesn't stick to the fluid particles. the particles pass through the noise texture and so their viscosity changes every frame. same happens if i just paint the color onto the geo, once the i start the sim the color attribute stays static in world space and the fluid just passes through it (if that makes sense). Anyway Im sure its something simple im overlooking but any help around how i can get the noise texture in sops to map and stick to the fluid in dops would be awesome. Cheers.
  21. flip object explosding

    hey! I'm trying to turn a deformed box into a flip and let it explode (the deformed box is just to fake some numbers exploding into water). I'm looking into some way of applying a radial force to my flip sim, but metaballs doesn't work, not sure if I'm missing something...or if there's a smarter way of doing it... countdown_explosion_v002_t000.hiplc
  22. Caramel Goo Tear Apart

    Hi everyone, my first post, newbie to houdini but diving in! ive been trying to find the best way to achieve the classic mars bar chocolate caramel bar being pulled apart in close up detail, where the caramel slowly tears apart with strands becoming longer and thinner as it gets pulled. kind of like the classic bubble gum on the shoe type thing. FEM ive tried fem, but couldnt get it to become strandy enough and then completely tear apart. love to know if i continue to explore fem that it would be possible to make this effect. GRAIN SOLVER?? perhaps the grain solver with some noise determing the glue strength so natural tears become apparent in the grain block as they get pulled apart? FLIP: VISCOUS FLIP viscous sim perhaps might work? anyone experienced think this could be the way to do it? im hitting lots of newbie dead ends, so any help on which avenue will actually get me the desired effect, id be much appreciative. J
  23. hi, i have a shot where i need to make boat interaction particle . waves deformation mesh seq are already made in maya . if in real flow we have real wave with object interaction .it create particles,but its bit slow compared to houdini. is there a way to do it Houdini ??
  24. calm flip water in custom conteiner

    I'm trying to create simple fluid scene - calm puddle water in some ground hole and some rbd object goes up through this water. But I can't get really calm water - my flip particles can't stop during 100 frames and more. How can I fix this problem? my scene with some cache files attached below water.7z
  25. Hi, I have general questions about FLIP. For instance, there are splashes like an attached picture. If I want to change velocity or delete splash/spray, I think there are 3ways. The FLIP concept could make it tricky because FLIP contains particle and volume fields together. Thus, questions are: 1 - in general, if I want to change velocity or delete splash, do I need to modify the both of particles and field together? Or just modify one of them? 2 - It's kind of similar question as #1, but, when we use sinkFLIP and pump and sourceFLIP; 2a - pump seems to add velocity, but it's strange why source volume sets copy, and velocity sets normalized?? It should set source Volume none, and set velocity normalize OFF. Also, why don't we use pop node to change particle velocity directly?? 2b - sink seems to just kill particle, but why sourceVolume is maximum? It should be subtract although it's not exist.. And there is still surface volume exists after deleting particle... Can't we use just pop kill to remove waterVolume/splash? 3c - sourceFLIP looks just adding particle. I guess we can add velocity with particle together, then when it passes solver, it create water volume (surface field and vel field), then why don't we just use pop-source to add particle with velocity?? 3 - There is FLIP solver > particle motion > Droplets > and min/max particle Density. However, there is no density attribute. What density talks about and how they calculate density?? Thanks for reading a lot of questions!!