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Found 156 results

  1. Drop of water simulation flip

    Hi!! I'm trying to Drop of water Fx ・Reference movie https://vimeo.com/14054601 https://forums.odforce.net/topic/30773-water-drop-splash/?tab=comments#comment-171664 The conditions I want to do 1.Water droplets are small like sweat 2.I want to make a series of fall and bounce 3.I want to shape like a crown The data I was making is this, but bounce does not work well can you help someone drop_190419.hipnc
  2. Problems with two FLIP objects colliding

    So I'm in the middle of creating a waterfall scene which is going to flow down some geometry and collide with a lake. I've set up both the emitters for the waterfall and the wave tank for the lake in separate DOP networks. However when i try and bring the particles in from the waterfall into the lake DOP the particles don't seem to be having any interaction, the waterfall particles just fall though my static objects even though they should be colliding. Any help would be appreciated Thanks. Edit* I've noticed that the bounding box in the flip solver was not including the waterfall particles which fixes the problem of them not moving however the particles still do not interact with the wave tank. WaterFall_New.zip
  3. houdini beach

    hi,guys Who has this beach file?There's something wrong with what I'm doing. there's something wrong with the edge. the water can't get down on it. thx.
  4. Hi everyone this is my first post in this forum and I wait posting more in the future :-) I have a problem with alembic geometry (animated) and fluids. I try to make a Helmet Visor(alembic geometry) melt with corrosive acid. I follow this tutorial * but my geometry (alembic) not collision with fluids. I'm converted Alembic geometry to polygons, but the problem persist. *Tutorial: https://www.youtube.com/watch?v=JW6XamYSdpU Can anybody help me, please. Thank you so much.
  5. I have a Ragdoll Simulation of a Character that is falling into water. Everything is working so far but I can't get the Water to affect the agent. He is just falling through the water like it's not there. Even when I set the Feedback Scale to very high values the Character won't float on the water at all. When I use a simple geometry like a sphere instead of the Agent it will float on the water correctly. Any Ideas what is causing that?
  6. Hi there, I got a curious question that I was hoping someone might shed some more light on if possible. What's the difference between the old sph solver, the particle fluid solver, and the new pop fluid solver? Is it all the same thing but wrapped in a new package, or do they have different utilities? Thanks, Felix
  7. Split Half Underwater

    Hi there everyone, I am trying to recreate this shot from shutterstock as accurately as possible in Houdini: https://www.shutterstock.com/video/clip-14617168-slow-motion-split-half-underwater-close-up Creating the wave I imagine is pretty straightforward, and have done so before using realflow with good results, but the main challenge would be how to handle the thickness of the surface of the water as it intersects the camera, how to render different environments for the under and above water portions, how to handle these (previously I used masking with mixed results), and then secondary elements like the bubbles that form with splashes and the distortion to the above water image caused by water splashing over the camera lens. Would ideally like to use redshift to render this, but anything that can go towards achieving a photorealistic result, or any idea or resources anyone might have or can point me towards would be great. I'm a beginner in Houdini but relatively experienced with 3d in general. Many thanks, H
  8. Hi all, Relative noobie here, looking for general advice on how I might approach modeling a cancer cell that looks like this: https://www.mskcc.org/sites/default/files/styles/width_800/public/node/167374/3x2/sciencesource_ss21694540_1200x800.jpg [www.mskcc.org] or this: https://static.independent.co.uk/s3fs-public/thumbnails/image/2016/02/15/21/1-t-cell-corbis.jpg?w968h681 [static.independent.co.uk] One physical feature of the cell that I’d like to pull off convincingly is the sticky-looking tendrils that shoot out from the membrane, that look a bit like viscous liquid has been shot out from the surface of the cell. Though something like the image in the above links would be ideal, I would settle for something like this: https://lymphomanewstoday.com/wp-content/uploads/2018/09/shutterstock_565670083_zps0eglo9ri-1000x480.jpg [lymphomanewstoday.com] I would want to avoid something like this (where the tendrils resemble veins, or maybe octopus tentacles: https://www.segnidalcielo.it/wp-content/uploads/2017/08/GoldNanoparticles.jpg [www.segnidalcielo.it] Since for now I only actually need a static model, my first inclination would be to start with a simple POP setup, have some particles explode off a spherical surface and append a trail SOP to get the tendril trails. I’d run the sim and use a single frame from it as the cancer cells base geo. This only gets me so far though, as there are other important visual details that I’ll refrain from talking about until I some experienced person can tell me that this is definitely the way to go. My other inclination, which I realize might be inviting insanity, is to create a “fluid explosion”, using a FLIP setup with some velocity noise coming from the SOP level, and playing with DOP node settings to get the right kind of viscous/stringy effect from the particles. From there, again, I’d run the sim and use a single frame of geo for the base for my model. I’ve so far made an attempt at this (file attached), though have only tried seeing what I could get by using nothing but some noised-up velocity on the SOP source, some DOP gravity and tweaking settings in DOP Source Volume and Solver nodes, pertaining particularly to viscosity and surface tension (though I’m not sure the latter is relevant). I’m able to get some neat looking effects, but not really the ones I’m specifically after. What I’d wonder here is whether this ‘explosion of viscous fluid with a very high tensile strength’ could even be achieved with a fluid sim, and if so, would I need to push/pull the “sticky/stringy” fluid outward by having the FLIP particles stick to a set of “collision” particles which are then launched outward, pulling some of the fluid along with it. Or, could this effect be achieved by simply applying velocity to a Fluid Source SOP with very low particle separation, and then relying on settings available in DOPs nodes to get the long / stretchy tendrils. In any event, I’m certainly open to suggestions even if they’re completely different approaches to what I’ve described above. Thanks ahead of time to anyone responding! Nik pF CancerCell_FLIPFluidFromObject_v021.hipnc
  9. Hi, new to Houdini! What’s the best workflow to advect particles with fluid on a fast moving object?
  10. Fluid surface UV question.

    Hi folks, I'm a games artist and am new to Houdini and I'm looking for a bit of workflow advice for an effect I'm trying to achieve. I'm wanting to make a melting head. I've got a UV'd head and I've put a skull mesh underneath that will be revealed. I've added a viscous fluid melt operator and the head melts and drips nicely. I would like to put it into UE4 as a realtime effect. The issue I'm having is that the melt mesh has changing topology and I need stable UV's so that I can apply my head texture to it. Is there a way to do this, either by taking the UV's at the first frame of the sim or by point deforming my undistorted head mesh to the simmed mesh. Or should I consider another way of achieving this effect? Any thoughts would be appreciated. Cheers, Paul
  11. I'm trying to make custom velocity field in fluid dopnet. but I couldn't find any tutorial with this.. there are only version before H17 and some are about Pyro. when the fluid particles passes that box on right of the view, velocity pushes particles to its own velocity direction. Can you tweak my hip file for it ? I'm having problems with how can I make box to vel field, and set volume source node up in dopnet to use it as volume velocity. If you help me, It will be really big pleasure to me custom_velField.hip
  12. remesh fluid sim

    hey! I'm looking into remeshing a flip mesh to constraint it to a particular topology, so basically I want to project a given grid vertically into a flip mesh surface. I think I can do it via the ray sop but I can't seems to find the right way
  13. Fluid Problem

    Hey, my problem are these boxes, which appears after some frames. I don't now how to get them away in the simulation. Maybe someone could help me
  14. Hi guys, I have a question concerning the new fluid source in H17. How can i create a pump source from curve (point) to drive a FLIP simulation (technique used to create a boat's wake effect) with the new fluid source pipeline. I'am really confused about the new pipeline, and don't really understand the benefics of that changement. I used to create this simple pump field in H16 with the old fluid source SOP. But now i can't find the way to recreate that, should i use Flip source SOP (can't make it work with curve as input), or the pyro source SOP ? Please if you have any idea to spread this technique in the new Pipe it would be awesome. I'am stucks and tried a lot of setup but no luck. Thx
  15. Hi fellow Houdini masters. I'm still quite new to doing fluid sims in Houdini. I am trying to create an effect of paint-like fluid flowing down a wall, colliding with a bottle and then continue flowing off the edge. I've set up a simple set up with shelf tools and controlling the emitter velocity with simple VEX. So the desired effect is to have the fluid flowing down the entire wall smoothly with a curvy edge, collide and fills up around the bottle, and then continue flowing off the edge and down. The surface has to remain thin, smooth and complete with no holes, similar to pouring paint down a wall. However, here are the problems i faced with my simulation. I've attached the flipbooks below too. 1) The fluid is too thick. I tried scaling the scene from small (<1m) to big (around 2m) and it still looks the same. The fluid gets really really thick when it reaches the bottom. I was thinking that increasing the scene scale would make the liquid thinner but seems like that doesnt do the trick. 2) After the fluid collides with the bottle, I can't seem to force the fluid to go around the bottle and fill back up. I've tried using a pop attractor but the results look unnatural. 3) For some reason, even though my wall volume collider guides look smooth, the fluid doesnt flow down the wall smoothly and seems to bounce off the surface. 4) Even stranger, when the fluid reaches halfway down, they start to float above the collider surface. This is very apparent in the side view flipbook. I thought it was some collision volume offset, but it was set to 0. And in other areas, the fluid was nicely touching the surface. Totally got me confused here! I've attached the hip file (with stickynotes annotations) and flipbooks of where I'm stuck at. Would be so grateful if I can get some tips of how I could achieve this effect. In my mind, I thought it was a relatively simple set up where I can just make a collider and emit viscous fluid down and let it simulate and flow down without changing so many settings. But damn its difficult.. =( Thanks! Wall Flow V01.zip cascadeFall_side.mp4 cascadeFall_front.mp4
  16. As the question is formulated, this is not an A vs B. I have Houdini and it's the heart of everything 3D in the pipeline, but I have worked a bit with Realflow much earlier (when I used to work with Maya) and I wonder if it's worth it to add RealFlow to the pipeline or you think Houdini has everything for fluid simulations. I haven't yet worked with Houdini oceans and fluid simulations, planned soon, but I'd like to know whether I should use the discount period for adding "game changer" applications to the pipeline. I know what I can do with RealFlow, but I do not know how much of that can be done with Houdini. I need small as well as large scale simulations, not just oceans, also playing with fluids (swirling around pillar and other stuff) Why would you add RealFlow to your pipeline if you already have Houdini?
  17. Hi there good folks, So I've been asked to make that famous effect of various colored paints layered upon each other, dripping to the ground. The dripping? No biggie. Getting the colors to NOT mix together? Urgh. Or rather, as the flip sim goes, particles spread under / over the other layers, resulting at the end of ends in a spotted mesh with no real foreseable tricks to get all those to look like sharp separations. Here is a good reference : https://www.youtube.com/watch?v=P6TnO_Rr3G4 And another one would be : https://vimeo.com/225438054 How my work looks so far, you can really notice the spots : Aaaand joining a scene. So how could I proceed to prevent the colours from mixing together too much? I've thought of getting a particle force to repel/attract based on color, but it will just make weird things happen. I've thought of getting a texture in there, but I do'nt see how I could make it look right or apply it correctly to the mesh. I've thought of manipulating various fields, adding some kind of divergence, etc, but really I'm not sure what to do. Maybe it's just a post sim trick, too... Paint_drips.hip
  18. Fluid Drop Simulation issue

    Hey guys! I'm working on a project using fluid to simulate a drop (something like oil drop) falling and colliding with an object. The thing is that the client ask me if I can separate the drop when colliding with the object in another smaller drop and I don't know how can achieve that, I'm looking for something like have different density in the same fluid object or select some particles inside that can be affected for another force but the fluid is fluid, not particles so I'm lost in that! BTW this is the sim (the second part is the fluid). Cheers! gota v1.mov
  19. Hello, I have a problem with a FLIP fluid scene. I fill a sphere and move it down and upwards. After this movement, I have the same amount of particles but not the same volume… By the way, are there any good practice collections for flip fluid? I'm still struggling with it. flip.hiplc
  20. Fill object with liquid all the way

    Hey pros, This sounds very basic but somehow i have lost too much time trying to achieve it. I have a character that is empty on the inside and i am trying to fill it up with fluid all the way. I have a sphere emitting particles and the liquid seems to be reacting correctly to the surface but as it pours it doesnt seem to go above a certain level. I have read about using divergence but everything i find online seems to use deprecated/now hiden nodes. I have tried enabling the “divergence” by attribute and add a pop wrangle with the divergence value but no success. I feel not so smart atm... could someone please post a hip for me? I cant seem to get it right.
  21. Hello, I have a simple simulation task, where a static object and fluid object simulate. Emit Particle Fluid from a box to the sphere, I wanted to have a thin line of liquid so I made a static object bigger and box smaller, this way it goes as a narrow water tube, but the particles go too far from the static object, how to fix it? Where to look?
  22. Hello Guys. I have a problem with meshing FLIP when flattening for ocean displacement. There's visible popping by one frame in refraction when geometry is coming out of water. Here's preview: And here's what's going on with mesh on one frame and next one: Anyone have any idea how to fix that problem? I've tried many solutions but without success. - Narrow Band is turned off - I tried subtracting collision geo from mesh but it doesn't work - Without flattening there's no problem because of the boundry, water has thickness and it's meshed together with space around collision object. If anyone have a workflow for meshing that kind of ascending, I would be very grateful for any sugestions. And if that will help, I'm sharing .hip file without cache files. flip_ocean_rnd_v004.hiplc
  23. Hi, I am currently creating a simulation with flip fluids that are affected by a vortex force. I need the velocity/lift attributes to be animated independently throughout the simulation, though no matter how I set the settings for either the sop geometry, or vortex force operator, the values will not change throughout the simulation. What is the proper method for animating these attributes for use in dops? Thank you,
  24. Tsunami Wave

    Hello, I am trying to create a tsunami scene in which a giant ocean wave bringing a large whale with it hits the ground and enter in the city. And of course, I am taking 2012 Shots as reference. Now which is the best way to create a wave like that and also I tried ocean waves node and merged that with ocean spectrum in wavetank_initial but in the fluid simulation particles do not maintain their shape and they just fall down and get mixed with the ocean(Please find attached screenshot). And in Wavetank_Inital it follows the pattern but I when simulate it in wavetank_fluid after some frames the hero wave just starts to fall. So, Whats wrong here, the Process or there is another way to do this effect? Kindly guide me on that. Thanks I have also attached the reference video. Ref.mp4
  25. 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!
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