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Found 627 results

  1. Boat explosion

    Hey guys, Here's a new project I'm working on as I have some free time. The boat is a free model from cadnav. The main rbd sim with instanced debris is there : https://streamable.com/pcayf I used the new rbd deform pieces for the mesh (which is pretty useful) and I'm looking to add some noise and more details to the edges later. I've made the explosions (but infortunately I have only 119 frames because it crashed, I may resimulate the explosions 1 by 1 instead of the 4 in a row) : https://streamable.com/sjcje I've also made a quick low res render to see how the ocean and the explosions behaved all together with a lil bit of comp (to match my background) : https://streamable.com/1sduw Now I need to add sparks, smoke trails, and flip white water, and maybe additionnal splashes, refine the ocean.. Cheers and happy confinement !
  2. Hello, I have set up a simple narrow band flip tank and am dropping a small object (cosmetics bottle) into the tank. The issue im having is on the first frame that the object collides with the fluid it shoots a bunch of random particles out that escape from the narrow band and then re-collide with the underside of the fluid and cause ripples on the surface that I dont want to create. The RDB sim is running at a time scale of 0.05 and gravity is the only force in the scene so its moving very slowly. The time scale for the flip solver is 0.1 to get some splash, but as you can see from the attached photos its not anything crazy. Can anyone suggest a way to either stop this from happening or kill these particles before they collide with the narrow band? Im not the most versed at flip so this may be a very quick fix Appreciate any thoughts or help with this!
  3. I have a scene where I am dropping a bottle into a flip tank all at small scale. The issue im having is that I am getting a quite a large space/void between the bottle and the liquid. Im trying to reduce this and make the liquid hug the bottle more in the beginning and not blow outwards and make this gap. The setup is an RDB of the bottle falling using gravity from around 10cm into the tank, both the RDB and Flip have been slowed down to 0.025 in time scale. I tried a number of things like lowering the velocity scale, upping the subframes from 10 to 30 in the RDB and upping the subframes in the DOP network to 4/5, and changing the surface tension and viscosity, but it still happens. There is no problem with the collision guide and I dont have any sort of surface offset on that either, it matches the bottle perfectly. You can see in the attached screen grabs that the bottle has barely entered the fluid surface but has created a large void underneath it blowing out the liquid. This is the sort of splash im aiming for: https://www.youtube.com/watch?v=npAuLi1y5AA Dramatic but close and not blowing out internally too much. I know my bottle is a different shape to that reference but my sim seems way off and I cant seem to figure out how to lessen that gap. Any suggestions I would be very welcome as nothing I seem to try is making the gap any smaller. Thanks!
  4. FLIP torque, rotation, spin?

    Hey guys, I have done a search but there are not many answers. How can I get a flip sim to have torque or self rotation? I have a slightly viscous, surface tension flip sim, kinda like paint flying through the air with sheets and thin streaks. I want some of the "heads or blobs" on the end of sheets and streaks to pull the fluid more than other bits, so it flips, flops, rotates around as if its not water but something a bit more sticky. See how everything just floats instead of any torque? Any ideas? Cheers!
  5. Kinks in stretchy flip sim

    Hi all! I've got a stretchy flip sim, which is for the most part working as I'd like. It's a fluid that is being pulled apart with stretchy bands being formed. However I'm finding that when the bands become too thin, they begin to kink in a strange way, like in the attached image. I suspect this is something to do with the high surface tension in the simulation. I've tried may different adjustments to the settings, including upping the particle count, and substeps, but without any luck, Any advice or steer in the right direction to resolve this would be hugely appreciated! David
  6. Hello Community, I am having a problem that the FLIP particle doesn't collide with other parts of the flip particle. I have a simple scene that has a tank and emitter in the air. I want to pour the liquid into the tank. I was expecting that is going to create some splashes but it will just going straight down to the bottom of the tank. Does anyone have any idea? Thank you in advance. Flip_Test_v03.hiplc
  7. I'm currently working on a melting scene where I have a number of objects that need to melt into a combined puddle. The way Im currently doing this is by converting the objects to points, giving them their attributes for density and viscosity before theyre taken into dops to run through a flip solver. From my testing and limited understanding, I believe its not possible to have the fluids as seperate flip objects because I couldnt get them to properly interract with eachother in the sim. Now for values which have attributes in the flip solver its no problem to assign these per melting object but what I want to be able to control is the particle seperation for each. I can change the point seperation in the pointsfromvolume node, and link this to voxel size in my vdb from particles node in my meshing process, but how would I also link this per object in my flip_object node in dops? cheers
  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. Hey! Imagine you are slowly closing the water tap. then the water will decrease slowly. right !!!.. with reducing its thickness. That is what i am looking for. Animating the activation key on the "volume source node" would stops, right way. but i don't want that. Even animating the particle separation is killing the details of the shape. i want it to slowly stops with some kinda details. should i animate the scale of the object (which emits particle) or is there any other way to slow the emitting region or something. any one can help me please!? thanks in advance
  10. Good evening everyone! I learned some lessons and trained at home in Houdini, and tried to make realistic fluids together in vials for honey and chocolate, other types. I looked at pictures on the Internet and carefully studied how to create bubbles, and tried to make mantra materials. but it’s not like photographs of real honey bubbles. I uploaded - a rendering image and a project HIP. Help me how to create materials correctly? hdri.rar honey_colorls.hipnc
  11. FLIP Retiming jitter

    Hi everyone, I'm trying to retime a flip sim, but the retime node is creating a jittering when interpolating frames. Would this have anything to do with particle ids or num of particles changing between frames? and this is mucking up the interpolation? Thanks in advance, David RetimeJitter.hiplc
  12. Flip sim flows trough collider

    Hello Everyone! I am learning fluid simulations, and I have no idea why my particles flows trough the container. Maybe there are problems with the voxel size (vdbfrompolygons),or something is missing in the flipobject or in the solver? Could you please gave me some advice? Thank you for your help in advance!! 2020-04-14_v003.hipnc
  13. Hello; In Houdini 16.5, I would like to add "viscosity" to a "Particle Fluid" simulation using a noise pattern, so in DOP I add a "POP-VOP" node (and AANoise in it ... ) after "Source Volume" which doesn't work. Where could I apply noise to the viscosity? Thanks for helping. Viscosity.hip
  14. beach tank flip streaks

    Hello! I'm having a problem when doing a beachtank. The motion of the waves looks good, but when the waves are retracting, there is a bunch of points that stops moving and forms a line that does not move. I've tried to increase the substeps of the DOP, but it didn't make a difference. My beach has a slope and it doesn't look like there is something else affecting it. Any help is appreciated, thanks!
  15. Hi... I have created a scene where ocean waves hit sand... Used the beach tank from Oceans tool shelf. In order to accomplish the wetmap on sand I have taken the following steps: 1) Cached out the fluid surface cache 2) Scattered points on the fluid surface and added @wetness = 1 attribute 3) Used group bounding box delete to only keep the points near the shore 4) Scattered points on the sand surface and added @wetness = 0 attribute, points inherit UVs from sand - note sand geo has UV textures applied on the diffuse and other channels. Y axis projection, scale = 15, 15, 15. Resolution 8K. 5) Created another geo and object merged from #2 and #4 6) In that geo created a solver that: - copies wetness attribute from previous frame of the sand-scattered points onto current frame - uses attribute transfer to transfer wetness from fluid particles 7) This works great... so I have points scattered on the fluid particles transfering wetness attribute to points scattered on the sand particles. But how do I convert that into an animated map that I can load onto the original sand object? How do I blend that map with existing textures? - I have tried to follow a tutorial where author created a vopcop2 generator in img context and created the flow in VOP as per attached file - But this is not really working well... (a) its very slow (b) I get a small something that doesn't seem to animate or read the exact details of the points. Is there a better way do do this? One that might actually work? Huge thanks.
  16. 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
  17. Hey all, Ive been following a tutorial on how to transfer the UV's to simulated flip fluid and all was going well untill I added a remesh node to the transferred UV attribute which was supposed to smooth out the mesh to preserve the detail of the texture. Instead what has happened is that the UV's have gone from being seperate shells to having all their edges connected together. There is already a vertex split in the node graph which fixed the issue before I added the remesh node. Any help would be greatly appreciated, I've provided the scene file - thanks a bunch Melting_Example_v001.hiplc

    Hi all I'm stuck with this. What is the best way to mix two fluids that have different parameters (i.e viscosity)? Both will have different shadings. Any ideas. Attached reference scene. Thank you very much to all Mix_flips_RnD.hipnc
  19. Flip Source From Points

    Hi everyone I was playing with the flip source node and I am wonderig : is there a way to create a flip source from points, instead of from geometry ? For exemple now I want to create a flip collider from a point simulation, if I want to use the cool flip source node I have to create a vdb from particles + convert vdb to mesh + flip source, I guess there would be a more efficient way ? Have a good day, thank you for your time
  20. Hey wizards! So I'm working on a project and I'm tasked with doing an inverse whirlpool. I've tried several techniques like curve force and axis force but they become unstable and don't give the desired effect I need. I'm currently using pop particles to affect the flip and it works, but it continues to grow then it becomes unstable. I'm trying to recreate the effect in the pokemon video but I need it to run for a long time without being unstable. What would be my approach to achieving this effect? Here is my hip file that I'm working on, maybe someone can notice if I'm doing something wrong lol water swirl.flv smalltornado_unstable.mov smalltornado_unstable2.mov watertesting_forum.hiplc
  21. houdini flip blood drop

  22. Hey I'm currently working on a high res ocean simulation and I am really struggling with a volume loss of the flip simulation over time. I already did a bunch of research, but nothing seems to work so far for me - maybe I did not get everything right in the threads i did read. Here are some things that i tried to work on: - I tried working with the gas equalize volume Microsolver (I calculated my goal volume, but as soon as I started the sim got slower by the factor of 10 and "exploded" after the first Frame) - I tried decreasing the grid size, but to be honest I dont really think thats the issue - the surface looks already really clean with the default resolution - Right no I try to run the sim with "particle separation" activated, but it also gets really slow, and I think there has to be a better way Is that an issue that some of you already faced ? in the attached pictures you can see, how the water level is way underneath the water level, that I would get with the ocean spectrum preview (in the beginning it matches, and over time it gets worse) Would be great if you might help me cheers Felix segelschiff_ocean_sim_V007.hip
  23. Hello everyone. I'm trying to make a simulation of a fire hydrant spraying water at a high velocity. I'd like my effect to look something like this: FireHydrant1.jfifFireHydrant2.jfif I have the FLIP fluid behaving how I want it to, but the water looks too clear. I would assume that whitewater could fix this. However, I don't know which settings I would need to change for the whitewater to encompass the entire fluid shape like it does in my reference pictures. When I use the shelf tool, whitewater is only produced on the leading edge of where the water is first sprayed, like this: I don't really know where to start, and would appreciate feedback from anyone with more experience. My .hip file is here: HydrantHelp.hipnc
  24. This is one of the FX development I did for the Chinese animated feature 哪吒 (NeZha). All the FX are done in Houdini using flip and custom airfield to generate the waterfall effect, rendered in Mantra and final comp in Nuke.
  25. Greetings, I have few microsolvers in my Flip Solver>Volume Velocity and I want to apply them to only 1 of my 2 emitters. Do I use a POP Wrangle after my MicroSolvers like (if viscosity > 500 then apply) or do i need to make some initial groups of my particles and apply the micro solvers to the favoured group ? To be more specific I use a GasMatchField and a GasStrainIntegrate with a GasStrainForce and I have 2 Volume Sources. If for example I go to my Popdrag in Groups I can see the option "stream_volumesource1" or "stream_volumesource2" but nothing like that in the microsolvers.