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Found 177 results

  1. If you're flip simulation flickers from using reseeding particles this threads for you. TLDR: I've found a temp solution but want a better one. Inside the flip solver search for a node called "Gas Seed Markers"(Its renamed to "Reseed Particles") Uncheck the "Build Inside Surfels". This will stop the popping but maintain the effect of deleting the unnecessarily dense overlapping particles. Starting this thread for myself to document my thoughts on this but also for anyone else who needs reseeding to keep their simulation in check. So far I have a temporary solution to my issue but I want a better one. My hope is that we can discuss a better means of achieving the desired result of consistent fluid particle density without flicker or popping. The masterclass doesn't explain reseeding and I couldn't find much on the topic in forums or elsewhere for how it works. The node responsible is Gas Seed Markers(GSM form now on). It checks the number of particles per voxel within the surface field for inside the fluid and outside within a given number of boundary voxels and does three things. A. When particles exceed the desired density per voxel GSM will cull the points of that voxel. B. If voxels beneath the surface do not have the correct density GSM will add points. C. If there are not enough particles on the surface, within 2-3 voxels GSM will fill that voxel with the desired number of points per voxel. It seems on one frame the GSM node will delete ALL particles within a voxel that exceeds the limit. Then the next frame, because the void was created it will then repopulate the void with the desired density. So this is where I'm hoping for some help in understanding, in order it's: 1. GSM determines particles are too dense. 2. GSM deletes all particles in voxel. 3. Complete solve (particles partially close in on this void) 4. Next Frame of solver - void still exists so GSM adds particles to this voxel with points = Flicker / Pop. So to start the thread: First - Does Gas Seed Marker delete all particles within a voxel that exceeds the density limit or is this an optical illusion? Second - I'm having trouble getting this node to function outside the context of the flip solver. I want to see it populate points into the Geometry data but it has a lot of requirements regarding the slice index that I don't fully understand. If anyone has or can create a working example of this node functioning outside the context of the flip solver I would greatly appreciate it. For now I'm going to try using two GSM nodes one after the other. The first only performs the cull operation and the second performs the fill before processing the solve. Will post back with results shortly.
  2. DOP to POP

    Hi guys! Just looking for a little bit of help, to see if what I am trying to achieve is actually possible and if it is maybe someone could assist me in figuring it out! I have attached my file below, I am attempting to make a Volcano react. This is the reference I am trying to copy to the best of my limited abilities! https://www.youtube.com/watch?v=9Plj4b79cwg My question is in regards to the node named SIMULATION, ignore the first DOP for the first smoke. I am working on the out put from the lava, now everything looks horrible, but I am trying to get the set up to work so I can edit things all at the same time (Uni assignment, short time frame, was recommended to do it this way.) Anyways I have the 'Lava' moving kind of how I would like for now and I now want to take the movement of the lava and turn it into particles to put into a POP to create small particles/sparks. I am certain this could be done. But I cannot wrap my head around how to achieve it, I got it done for the secondary smoke from the lava plugging the output into a pyro, which I haven't edited yet so that reaction is a bit of a mess. But I want to figure this out before moving on! Any help or recommendations would be hugely helpful! Or even if you know of any tutorials that walk through this? As I haven't come across any.... Thanks! Assign07e2.hipnc
  3. create flip tank inside object

    hey there, im newbie to houdini and here. Im trying to achieve fluid in bathtub, easiest way seems like using flip tanks. But i don't know how to do that with custom shape instead of box. Also i will add some rigid bodies top of that water later. Also i tried to fill it with particle emitters but i couldn't success. Also how i freeze it after it fills, initial state ? In short: bathtub with water, floating rubber duck and some other model in surface. attached scene file. bath.hip
  4. (I'm not good at English) I wonder How to I delete the particle from collision boundary. according to the Kill Inside Collision is Delete any particles inside any collision objects plugged into the second input. flattank size equal bounding box group to create .. um.. I need solution and vex sentence. Would you explain this ?!
  5. Simulating flip from bottle

    Hello everyone. Long time since last post here when i was dealing with the same thing. After watching some tutorials and learning some more in houdini i decided it was time to go back and see if i could get some better results. There is still some big questionmarks that im seeking answers for. Here goes. This is the simulation i want to do. Animating a beer bottle (prefferable in maya since i have a rigged character and i have made a animation that matches footage so i know that the animation is timed correctly and so on. The bottle will be pouring beer into a pretty standard glass. When i have a stable flipsim i would want to go on and simulating bubbles and foam. So on to the questions. 1. I have noticed some differences between using collision geometry made in houdini or imported geometry. Making the geometry in houdini seems to work much better for some strange reason. Can anyone confirm this? It seems that i get away with much higher settings on particle separation and gridscale then using similar objects imported from maya. 2. Scale seems very important here. Simulating in real scale gives a lot of trouble. therefor i scaled the bottle up so that it is around 1 meter high. However, this gives some problems when it comes to actually using the animation i made in maya. Everything in maya is done in centimeters and when importing it to houdini its way to big. I ended up matching the animation inside houdini from the imported file and used that instead. Wich is the best way to get around this? Usually in production everything is modeled in correct scale in maya. 3. Setting up the flip source. Is this the correct way? Import the fbx file with the bottle. --> create a new geo node --> create a box big enough to cover the bottle and up to the level where the liquid should end at the bottleneck. Object merge the bottle into this geo and connecting a boolean with subtract b-a settings. Then i blast the exterior so i have only the interior of the box minus the bottle. 4. In the bottle geo i have a transform and after that a null. i put the displayflag on the null and then create a deforming object from that. 5. finally i create a static object from the imported glass. Now all is setup to start simulating. ofcourse there is alot of tweaking of particle separation and collision settings to be done but overall is this a good setup? I can post a file if that helps. Finally some other questions. When caching out the flip to simfiles i only want the particles to be cached. where do i set this up? Regarding substeps, if i raise the substeps INSIDE the dopnet on the flipsolver will this generate more substeps when caching it out or is it only the substes on the dopnode that sets substeps in caches? Sorry for kinda of a long post but if anything can be answered i would be grateful! THX!
  6. Flip Sphere Motions

    Hey there, I'm trying to replicate this setup: Liquid Sphere Based on my scene, I have a sphere and the particles are generated from it with iso offset and particles from volume. Within FLIP, I tried to control the velocity with pop forces (POP force, pop attractor and pop axis force) and got somewhat of a swirly motion but the in the reference video, towards the end you can see the fluid is ground around a torus like motion and the shape as well Any pointers on achieving this? HIP file attached included. Thanks! SH02_Water_v02.hip
  7. Hi, I have an issue that I have not been able to figure out. I need particles/fluid to follow a curve, which I know how to do easily, but this particular curve crosses over itself a couple times so using Volume Velocity and Curve Force causes to particles to divert off by grabbing on to a later section of the curve. (ref images attached) Is there a way to restrict them to the current section they are on so that they ignore the areas where the curve crosses over itself? I have not been able to figure out a way to do it so I thought maybe the amazing Houdini brains on here might have an idea? Thank you in advance for any help/suggestions you can offer!
  8. Hi there everyone. I am having a really strange issue with my river scene when I render it out. The reflective of the water seems to turn on and off randomly. I then did some further testing and found it to be the interior Volume giving me issues but this only happens in the center section of my River, the Top and bottom are not affected by this problem. Below I have two Images to show the result of the Volume issue which is consistante on these two Frames even if I re-cache the Sim Frame 350, the Volume in the center is really Thin. Frame 357, the volume is much Thicker in the center. Please check out the Link HERE for a low quality render with a few frames on Vimeo. Password : JodysFX I feel like there is a setting I am not turning on or a value thats two low. It might be in the Surfacing node but I am not sure, I will continue to test. Any help is greatly appreciated.
  9. I have a fluid container from which the fluid has to be sucked out through a straw ? even a small hint would help. pls help././.
  10. Hi, I'm currently working on a project where I'm trying to bake a displacement map and normal map for a number of different waves. I have a method for baking the waves, which have been created in Maya and imported as an FBX, but want to get extra detail on the wave surface. I managed to get the ocean spectrum to use the animated wave, but the problem is that the bake needs to tile and the displacement of the ocean spectrum doesn't. I'm having trouble figuring out how, or even if its possible to create a fluid simulation that can use the wave animation. Thanks in advance.
  11. Bullet to Fluid and Vellum

    Hello Everyone, I have just create tutorial of making dynamic to fluid and vellum in Houdini 17. Check in here: https://www.cgcircuit.com/tutorial/bullet-to-fluid-and-vellum Best Regards,
  12. Hello! I'm trying to make an effect where a logo emerges from a tank with a viscous fluid. I want to have the liquid quickly flow off the logo once it emerged. It has a round surface, similar to the torus I exchanged it for in the hip-file I attached. I'm aware of viscous fluid's stickiness and turned on "slip on collision" and also tried the "gas stick on collision" cheat I found in some older thread, as well as using normals to drive the velocity. however some particles always stay on top of the surface and won't flow off. What would be a smart way to cheat and clear the surface of the fluid? Thanks in advance! J. 190620_Instagram_FlipTankExample.hiplc
  13. 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
  14. 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.
  15. 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
  16. 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.
  17. 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.
  18. Volumetric Temporal Deflicker 2.1

    Digital asset download at Orbolt! Enjoy https://www.orbolt.com/asset/RodTD::Rod_vdb_averaging
  19. 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.
  20. 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
  21. 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!
  22. 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
  23. 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
  24. 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.
  25. 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.
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