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Found 166 results

  1. Volume source random activation

    Is possible to have my particles from the volume source activated at different frames? i am using a noise that i remap to frames to control which parts of my geo get activated when
  2. Pyro sim with moving emitter

    Hi all, I'm kinda new to houdini and i'm doing an animated pyro flame sim and when my emitter moves the fire doesn't follow the emitter, it looks like the emitter keeps working but the smoke and fire can't generate, i've attached photos so you can take a look, if you know how I can get this working i'll really appreciate a response. By the way my emitter is a torus, that's why the shape in suspension is a circle. Thanks!
  3. Fluids - help!

    Hi team! I have followed a good tutorial on Youtube as I was having issues with keeping fluid in a container, this tutorial also shows how to do bubbles in the water ( Tutorial here ) When the bubbles go through the water there is a loss of fluid and I have been playing around a lot trying to figure out how to prevent the loss, when the collision objects aren't connected there is no loss in the amount of fluid but when I connect the Collison object there is a loss of fluid and I cant figure out how to stop that. I was wondering if anyone else happened to know? Its just bothering me and I wanted to know the answer. Cheers! Hottub.hipnc
  4. Hello. This is my first time asking I think it's a long stretch because of the orange part, but I don't know how to solve it plz help me
  5. Houdini for Beginners - 005 - Vellum

  6. Maintaining Voxel Size in Sparse Pyro Sim

    I have a sparse sim in which several pyro events occur at different times & different places. As new elements are sourced into the sim, the overall bounds of the sim increase - sometimes dramatically changing the quality of the sim as the voxel size adjusts - see two back-to-back frames below. is there a way to maintain a consistent voxel size throughout the duration of the sim while using the sparse solver? Thanks, Luke
  7. Xgen fur to Houdini Sim

    Hello wizards. I need to simulate fur that was generated in Maya Interactive XGen (don't ask why), it has about 2 millions prims. I load it as guides (part of it, for test) and it simulates ok. So now I want to figure out what would be the best workflow to simulate the whole fur, as it seems to me it will be quite heavy to sim 2mil curves. I'm looking for optimization. Any suggestions would be highly appreciated.
  8. Hi, The problem is getting RBD Bullet pieces to floating properly: Icebreaker_fake_Buoyancy_Bullet_SpinningProblem.mp4 IceBreaker_Ship_PopForce_VexMask.mp4 im running into problem simulated flat sheets of ice being buoyant in a volume. I can get them to rise to the surface with PopFloatByVolume and also a fake popForce with vex using the pieces depth to mask the upward force. The problem is getting them to not spin around the packed bullet point per piece, and instead have proper per point of the mesh have force applied as per proper buoyancy would. So they lie flat once they get to the surface of the water volume! Struggling with the PopFloatByVolume spin settings, and PopSpinByVolume doesnt seem to play ball either. Im trying to go down the setPrimIntrinsic route, where i could blend slowly the rotation to be flatter as they get to near the surface, but im not hitting gold yet and would be great to know if theres a better route. any ideas or approaches would be amazingly appreciated. attached the hip file with where im at. IceBreaker_PopFloatVol_CustomVolumeInput_005.hiplc
  9. Membrane tearing

    Hi gang ! Here is my latest vellum file, I played around with noises and constraints. My goal was to emulate a membrane tearing, much like a burning film: You can download the hipfile and play around with it tearing_share.hip
  10. Hi there, I made a scene for simulating a piece of rope with the help of Vellum objects. Although it looks great, I noticed that when I use a polywire sop there is a lot of twist motion that makes the rope behavior unnatural. I posted the scene here so if anyone is kind enough to look at it and give me some suggestion for fixing the rope yaw rotation. thanks in advanced. RopeSimulation.hip
  11. Independent surface tension

    I am trying to achieve the effect of having a solid piece of geometry sitting as a fluid, being brought in by either volume source of pop source. This initial piece just has fluid ripples. The second part is I have emitters in the same dop network that are there to create a dripping effect. So it looks like this liquid that is holding shape is dripping. The problem is that I cant seem to create independent surface tension for the two separate sources. If I increase the surface tension to what I need then the main piece of geometry gets washed out. I have been looking for a solution to this but nothing comes up for Houdini 18
  12. How to fracture bricks for sim?

    Hey guys long time lurker first time poster. So I have a brick wall created in Houdini and I wanna blow it up. Got my texture projected and everything. The wall consists of several rectangular boxes all made in Houdini. Projection done in Maya. So now I wanna know the best way to fracture the bricks while still getting that interior detail on the "inside" faces of the bricks. Moreover, once fractured, how do I apply texture on the inside pieces? I know we gotta separate the inside and the outside groups first and then apply the material accordingly. However, when I apply the material (with a broken brick texture), on the inside group, it just renders a single flat color (the color dominant in the texture) . UV unwrapping the inside group and then applying a texture also doesn't work (renders out a single flat color). Maybe I'm doing something wrong Idk. So what is the best and most efficient way to fracture bricks and texture the inside groups? Would love it if you'll could share some tips to help me out. Thanks!! EDIT- I tried using Redshift. Thought that would be important to share.
  13. Fluid coupling

  14. pyro distributed problem

    is pyro distributed work with checkpoint ? i have 2 slice,output the .sim file with $SLICE variable work ,but when i try to resume the sim with this .sim file it will stuck. what i doing wrong?
  15. Hi Houdini guys, I'm doing a Pyro simulation using the instance function because of the smoke&fire of a long trail. I've instructed to create 10 clusters, but there are more than double as many containers created in the scene. The reason is that I'm increasing the sub steps in Dop network. I confirmed that the sub-step of 1 produced the specified number of clusters. However, I need to keep the substeps because the emitters are moving fast and the flames need to look nice in my scene. Is it possible to generate a container only for integer frames? If u have suggestion, I'm highly appreciate it. Thanks!
  16. Trouble with exploding RBD SIM

    Hi all, I'm still pretty new to Houdini, but I offered to do my friend a favor by attempting to sim a spaceship crash for his short sci film. It was more of an excuse to learn RBDs in Houdini than anything else, but now that I've invested this much time I really want to make it work. Anyhow, I started with Steven Knipping's Applied Houdini Rigids III Vehicle Destruction course and once I finished that, I tried replacing the supplied helicopter model with a spaceship that I modeled in C4D using a Kitbash kit, so I imagine the geometry shouldn't be an issue. It would appear that I'm very close to getting a workable sim because I got it crashing and denting with the original animation that I set up for the ship. However, I've been running into a bit of a snag if I change the crash animation. For whatever reason, if I move the ship at all to match any of the tracked alembic cameras I was sent, either by changing the keyframes of the crash itself, or even by simply attaching the entire animation to another null and moving it in the scene, the ship totally blows up. You can see what I mean in the last 3 previews found in VFTV\render of the attached project folder. Maybe I'm missing something very basic, but as far as I can tell this shouldn't be happening, as my understanding is that the hard constraints I'm using on most of the ship aren't supposed to break unless I tell them to in the art directed cuts section of the frac SOP. Anyway, the first preview in the VFTV\render folder shows that the sim more or less works with the camera matching but without denting, and the second shows the crash with denting but with no camera matching. But, for whatever reason I couldn't get the source tracked cameras working directly in Houdini, so I took them into C4D first, changed the resolution and alembic camera scale, and exported them at .01cm from C4D, and after that they seemed to line up in Houdini once I changed the camera view resolution to match. However, my troubleshooting brain is telling me that I might've messed something up during this process and perhaps the explosion is due to mismatching scene/camera scale issues with the alembic cameras that the tracking artist sent causing the sim to be calculated differently. I'm not even sure if the C4D camera scale option affects the sim in Houdini and/or C4D, but scene scale certainly does, and if the imported camera scale is messing with scene scale, then maybe that's the problem. That said, I don't think that's the reason, because if I leave the original animation alone it seems to sim fine even with the new cameras. And, I believe I'm matching the scale correctly and using the right conversion which is supposed to be .01cm from C4D to Houdini. I've also messed around with exporting different camera scales and scene scales out of C4D and importing the alembics back into Houdini using several different methods, all with the same result. But, I realize it might help me to know more about which software each shot was tracked in, so I'm double checking with the guy at Framestore, who did the tracks, regarding the scene scale conversions. I was thinking Syntheyes might be different from Nuke for example. That said, I would be eternally grateful if anyone was willing to look at the project and let me know what they think the problem could be. My hope is it's something stupid on my part, and not some overly complex issue. Here's a Dropbox link to a reduced version of the project with all the assets VFTV_Smoldering_Wreckage_1_200813_v001.hiplc
  17. Hi, I am importing an Alembic particle sequence from realflow. Shows up great in Houdini, no problems there. I want to 'mesh' it, I was thinking I would convert it to VDB and then to polys to have maximum control however the 'VDB from Particles' node is not taking the alembic particles (ie. nothing happens). Do I need to convert them to something else before? Am I approaching this completely wrong? Much obliged,
  18. Help with explosion sim

    Anyone know what parameter(s) is causing all the smoke to quickly fall towards the end of the simulation? explosion.mov
  19. VELLUM PRESSURE

    Hi I'm trying to control the restscale attribute using a custom attribute, so i can animate a noise and have it inflate depending on the color / custom attribute. I have added a vellumconstraintproperty and tried to use vex to transfer my atribute. But this is where i'm getting stuck. any help would be amazing. thanks VELLUM_INFATE_TEST_04.hiplc VELLUM_INFATE_TEST_04.hiplc
  20. Hi i have a question regarding narrow band in fluid sims: I am using an ocean source for my flip tank as source but how do I calculate the layer size in oceansource (thought its particleseperation*gridscale*narrowbandwidth) - because my fluid keeps dropping down when sim is running
  21. sliced ribbon cloth effect .

    Hi , is there any guide or starting point to achieve this kind of effect in houdini like this tyflow example ? https://www.instagram.com/p/Bm8nHNfApwE/?utm_source=ig_web_copy_link the confusing part for me not the sim itself , it's how he slice the geo in a continues sliced way ? any input is really appreciated ?
  22. Colored smoke gasupres with Redshift

    I'm working on a colored smoke sim in H18 and Redshift and I have problems setting up my color grids properly. Running VDB diagnostics tells my values in the range are invalid and my knowledge of how to find the error ends there. The idea with the sim is to create a low res sim, up res it, and add colors from the Cd attribute. Does someone know how to set up this sim properly? blueGreen010.hiplc
  23. Hey there! I'm quite new in Houdini. I do not really like to ask questions, I rather tend to find answers by myself. But sometimes I hit the wall. This is the case I need your help guys. Im trying to make RBD sim in DOP NET with the simple spheres. My goal is to have variable scale and color of a sphere according to the noise. I manage to get color with POINT VOP in SOP SOLVER with MULTI SOLVER. But I stuck with the scale of a spheres. They inherit pscale from a GEO level. I would like to use pscale in DOP NET and manipulate it with the POINT VOP. Any ideas how to achieve it? I tried to make it with the particles, like in this tutorial https://www.youtube.com/watch?v=qXoSEnh94YQ&t=246s But particles tend to move erratically and not act like proper RBD. Balls on plane.hipnc
  24. Attach Camera to Boat

    Hey All - I have an ocean in Houdini with a boat floating on it. I'd like to attach a camera to the mast, but can't figure out how to do it. Any ideas? Thanks!
  25. Smoke collison

    How do I set up 2 different emitters shooting smoke at each other and colliding?
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