Jump to content

Search the Community

Showing results for tags 'fluid'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • General
    • Lounge/General chat
    • Education
    • Jobs
  • Houdini
    • General Houdini Questions
    • Effects
    • Modeling
    • Animation & Rigging
    • Lighting & Rendering
    • Compositing
    • Games
    • Tools (HDA's etc.)
  • Coders Corner
    • HDK : Houdini Development Kit
    • Scripting
    • Shaders
  • Art and Challenges
    • Finished Work
    • Work in Progress
    • VFX Challenge
    • Effects Challenge Archive
  • Systems and Other Applications
    • Other 3d Packages
    • Operating Systems
    • Hardware
    • Pipeline
  • od|force
    • Feedback, Suggestions, Bugs

Found 165 results

  1. Hi; How could I apply velocity force to an ocean fluid, using an animated geometry? (I think I should use volume, but I don't know how). Thanks. OceanApplyForce_01.hip
  2. Hello! First time posting. I'm new to Houdini, this is my first project that I decided to do. But I'm a fairly seasoned C4D 3D generalist so I know what I want to do in Houdini, I just don't know how to go about it. I'm in Houdini 17.5. Here is the problem. I have stumbled around in Houdini and made a Viscous Flip Fluid Sim. I made a Sphere an emitter, and emitted my fluid pouring onto a .OBJ mesh that I imported in. I've cached the particle FLIP Particle simin the DOP network, the Particle Fluid Compressed Cached, and Particle Fluid Surface Cached. Now here is my problem. I exported my meshed sim as an alembic from a ROP_Alembic node. Imported into C4D. And then I realized I have a UV problem. This is a Redshift texture and shading pass that I did with my sequence. At the time I forgot to plug in the velocity data tags from the Alembic sequence into the Redshift motion vector blur, so if it looks weird, that is why. Crystal_Goo_Test.mov My texture smudges are on the mesh, but they stay static while the mesh animates. It looks just like the textures from this cartoon it doesn't move with it. So after a bit of digging I realize I don't even have UV's. Because Flip Fluids don't come with UV's, and if I never defined any UV's then how could they just magically appear? lol. So I tried researching how to generate them, and how to export them with the alembic. But for my specific situation I couldn't find anything that was up to date and worked. OR I am too much of a noob to implement what I saw in forum posts. The stuff I saw was for Houdini version 13, 14.5 and 16. I'm on 17.5. Here is a screen shot of how I tried to generate UV's and export them, again I never re-cached my sim yet. I just tried to put uv's on my existing set up. Below is my emitter. And there are no UV's on this sphere primitive, nor anywhere before the output. I took a shot in the dark and tried to see if I could generate them after all my caches (because it took 3 days to cache the fluid surface mesh). So I honestly have no idea where to generate these uv's, how to do it correctly, and how to get them passed onto the fluid mesh for alembic export and texturing in C4D Redshift. I'm including my .hip file with my cache's disconnected. They are over 200 GB's all together so it's too big to include here. Lower the substeps in the Flip Solver or lessen the Fluid Mesher to make it play back faster. I used high settings for my final export (also I tried my best to optimize, but again I'm a noob with Houdini and have probably done things incorrectly in my set up). Crystal_Viscous_Sim.zip The FLIP DOP cache might still need to be disconnected. This is the final step of my personal project. I've done all this on my own but I'm super stuck on this UV generation and export. And once I can export this fluid mesh an an alembic sequence for C4D Redshift I will be set to render. Thank you in advance for any feedback and/or answers. Please write out instructions very clearly for me to replicate if you don't want to provide pictures/ screenshots or .hip files. Again what I'm trying to do is generate UV's for my Fluid Surface, and have then be able to be exported via an Alembic sequence for texturing and rendering in Redshift.
  3. Boat on waves

    Hello everyone! I'm new to all of the simulations of wave and boat impact... But, i have read a previous post then was pretty interesting! That just here: https://forums.odforce.net/topic/28940-flat-tank/?tab=comments#comment-164200 After i'm trying to create this example, i have problem with my simulations... My boat doesn't produce a great whitewater and wave like this example... I share you my scene, i don't know why the boat doesn't push the water like the example :/ Thank already in advance :D!! Boat_simulations_geo.hip
  4. Tips for Eye Candy Fluid sims

    Hello there good people, Do you guys have any tips on creating eye candy fluid sims, Specially Flip liquid Sims? Thanks in advance.
  5. I'm in the middle of creating Whitewater particles for my waterfall sim and after caching out the particles and converting it into a volume it looks extremely low res considering there is over 300,000 particles and 8 million Voxels. Not sure what i'm missing but any help would be greatly appreciated. Thanks in advanced.
  6. Digital asset download at Orbolt! Enjoy https://www.orbolt.com/asset/RodTD::Rod_vdb_averaging
  7. Recreating an ultracentrifuge

    I'm trying to recreate an ultracentrifuge that seperates high density particles from low density particles. My current setup is two fluids with separate densities being emitted side by side to fill the container. Then once the container is fully filled I start up the "centrifuge", a pop axis force to spin everything at high speeds. The problem is it just acts as a blender and not a separator. I have a little divergence to pump up the fluid in the beginning but then it's removed. The densities are about 400 kg/m3 apart. I've tested fast and slower with different drags and settings but still just blends. Anyone else try something like this? Maybe I'm missing something important (more than likely, ha). Thanks! Update: kind of working now adding some mass, drag, and applying the rotation only to the low density particles. Faking it till it makes it I guess.
  8. Hi there everyone. Hope you are all doing well. So for a white now I have had some issues with Houdini 17 and 17.5 fluids. I am trying to create a river sim, but when I cache out my sim using Hqueue or just a "cache in the backgroud", The sim just stops or fails. This morning I woke up and had a Fatal error: Segmentation fault. I am was on windows but it was not activated as I had a huge hardware update but but it could nto find my Linked Windows key or something. I have now switched to Linux and I am currently on Ubuntu. This is my First time on Linux so I do not know what I am doing lol. I cannot even get Hqueue to Restart so I have to reinstall it every time. I tried this one, but it didnt work. My Hardware CPU - Threadripper 2970wx Motherboard - MSI Pro gaming Carbon AC Ram - 128 GB Corsair Vengence LP SSD - Samsung 2TB Please find the attached output log and Diagnostic Info. job_6_output.txt job_6_output.txt
  9. Hi everyone, i got a question and can't figure a way out. Imagine a bottle, and a mesh that perfectly fits into that bottle. I want to convert the mesh into a flip fluid and when i turn on gravity i want it to be as big as before. So my bottle is filled. The reason why i want that, is that I have a drop coming from above and falling into that bottle. When it collides with the fluid inside the bottle, I want a little splash and then the sim is done. How can i get a filled bottle that stays filled after I turn on the Sim. Maybe someone got the same problem or a solution, but i can't get my head around it! Thanks and Cheers!
  10. 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
  11. 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
  12. 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.
  13. 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.
  14. 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?
  15. 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
  16. 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
  17. 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
  18. Hi, new to Houdini! What’s the best workflow to advect particles with fluid on a fast moving object?
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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?