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Found 68 results

  1. Hi there, I'm learning how to make guided ocean layer sims and I have a couple of questions: 1 - I'm not familiar with caching system from Houdini. In my guidedoceanlayer_sim I have output name - $HIP/sim/$HIPNAME.`opname("..")`.$SF.sim - first newb question, should I use .sim or .bgeo? 2 - I've copied that name and after saving to disk, I 've pasted as relative references under DOP Network - playback simulation. I should see the sim, but I only see last frame of the sim and a bounding box around boat 3 - Under Ocean Source wavetank I have this expression under center - centroid("../mergefollow", D_Z) - How can I add or subtract a value since I don't need so much detail in the front of the boat and need more at it's back I'm learning Houdini so please be gentle. Thanks!
  2. Hi there, quite new to Houdini and I'm struggling to find documentation for something like this. I have a scene with a building where there are multiple fires starting at windows of varying sizes. This means I have different source volumes (fuel & temp, and a pump) for each window. I want to be able to render the pyro from each window separately and perhaps even have dynamic resizes for each source. The only way I could imagine doing this would be if it was possible to have multiple smoke object nodes that can reference different source volumes (the fuel & temp, and the pump). I saw that clustering exists but from what I understand it only accepts point sources? I am using a fluid source node building SDF from geometry to create the source volumes. What would be the best way of doing this? Thanks in advance and apologies if this has a very simple answer.
  3. RBD Fractured Obj with FLIP?

    Hello! I'm doing R&D for a project that will involve and egg breaking, releasing the yolk/white. Right now I'm just trying to get the principles down. I am currently just testing fluid inside an egg (making sure it stays inside when it's supposed to and falls with the egg in gravity) and am having issues with the fluid disappearing or leaking from the egg. I am used to using rbd packed objects for destruction so I started out my workflow with the egg as an rbd packed object, but saw some examples on here that suggested using an rbd fractured object so I have tried that as well. When I use the egg as a packed object, the fluid seems to just slowly disappear over time, and when I use a rbd fractured object the fluid sticks to the eggshell on the second frame and then flies out. I know the eggshell is thin geo for being a collision object (it is accurate to a chicken egg), but even when I thickened the geo I still had fluid disappearing. Any advice regarding using fluid inside rbd objects would be appreciated! egg.zip
  4. Hello guys, when i upresing pyro sim, CPU not calculating sim. it's spending 9 hours only 7 frames. i'm using Explicit Caches. Cached frame file size is 3GB. i don't know what should i do. Help me guys. Sorry my bad english....
  5. Detailed cloth?

    Hey magicians, I saw a cool animation and I was wondering how to achieve this effect, is this made with cloth + constrains?, love the detailed look on the rugosity, any tip will be great! Thanks!
  6. Hello Pals, Hope you all are having a great year so far. I am trying to do a shot with particles which needs slow motion on a certain camera moment. Basically, I just want to slow down the motion of my particles for few frames. I dont want to mess with the velocity etc as I really like the motion of my sim. I looked into time-shift, time-warp etc. But they always feel like a cheat and not much of a high quality solution. There is a "Scale Time" option on the POP net. But for some odd reason its locked and we cant key-frame it at all. That would have been the best solution, where we can just lower the timescale for bunch of frames and then resume it in normal speed. Can anyone just give me a brief why Sidefx would want to make this such a big deal and lock it on POP nets? Thank-you and have a great day! HD
  7. Fur Sim Issues with Scale and Settings H16

    Hello, Using the latest version of Houdini 16.0.736. What is best scale to simulate fur on female jacket. Should I simulate real-world scale or scale it up very large for better fur simulation performance? For Example, should the fur coat match the scale of the test geometry like rubber toy or pig head? Should it be scaled to 2 meters or 200? I want to master the scale before tinkering with the Fur Sim settings. Otherwise, does anyone have dynamite fur sim settings for a specific scale? My sims either seem very static or dramatically broken with stretching fur. Thank you, Ryan
  8. Hello, I was wondering if anyone had any suggestions as to why my flip fluid sim seems to "compress" as my container moves. Any help would be appreciated. Thanks!
  9. Flip Fluid Collision Problems

    Hello! I am having a problem with collision for my flip fluid sim, frame 2 for some reason a chunk of particles falls through the bottom of my "cup" I've checked my collisions on my "cup" and I've also tried adding a sub d node in my tree. both didn't have any result. Also, as the sim continues my particles pretty much all disappear. I'm pretty new to water sims so I'm not really sure the problem. Thanks!
  10. Hi, So I made an rbd sim where I had only 200 unique pieces. Then I made an rbd sim using 100s of each of these pieces. I cached the simmed points. After this, I want to place my unique pieces onto these points. What's the best and most optimal way to do this for the viewport and the renderer? I have seen many different techniques, I can't tell which one is the best. Should I just use Instance SOP? Should I save the first frame of the sim and use this instead? I can transform them using Transform Pieces SOP, but I don't know how to bring them optimally. Should the pieces be brought it as packed geometry, packed fragments, packed disk geo, or something else? I want Houdini to know everything is coming from these 200 unique pieces so it can show them more efficiently in the viewport and the renderer. I noticed if I save my pieces onto separate files as packed fragments, Houdini is saving the entire packed geometry onto each file that takes a lot of space. How do you do this? Thanks
  11. two objects in a granular solid sim

    I'm trying to set up two pig heads in a grain sim that collide together. an extension of the grainular solid example in Jeff Lait's h15 grains masterclass. in stead of one pig head i want to wire in two. I've set up two pig heads (skipping the bone group part for now) see attached file. Jeff shows how to override the P and v with from an animated version of the geo with a wragle. I've set the dop net up the same way with two sources. however for some reason one of the P values apparently collapses to 0. if i switch the merge order it switches which source goes to 0. see attached file. I'm obviously missing something here. help would be appreciated. twosolidpigs.hiplc
  12. Hi I'm new to Houdini and recently I've been getting into DOPs. I have a question I've been trying different things out in dops to see how they work, been playing around with the "Gas Match Field" node and found that it works quite nicely when both fields you are supplying the node with are from the same object Like on picture 1, both the "myField" field and the "heat" field are part of the same object and the node works just fine But what I can't figure out is how to make the node work when I'm supplying it with fields from different objects. On picture 2 "myField" is part of an empty object and the "heat" field is part of the smoke object, I tried to reference them via their paths like on the picture 2 but unfortunately it doesn't seem to work. Does anyone have any insight into why this may be, I can see how referencing field from different objects can come in handy not just for this scenario.
  13. Hi all, I'm getting strange artifacts rendering a flip simulation with the PBR shader set to glass preset. As you can see there are lots of flickering and some features of the mesh even go in and out. If refractions are turned off the problem disappears, however the desired look is no longer achieved. The problem is not present on other presets such as gold, etc. Im guessing this has something to do with how the particlefluidsurface node meshed the sim, being inconsistent with the inner features or something like that. Is this a known issue or something anyone have come across? Can you think of anything to help me resolve it? Thanks in advance, Glass_Test_s.zip
  14. Hey there, how would you go about changing the animation/simulation state of e.g. a cloth sim? I tried the pin to animation attribute to release the cloth object from the animation; but bringing it back to follow the animation is harder. it just snaps into place when I put the attribute back to 1 in the sop solver (dops). Also does anyone know a way to mix between animations and simulations? Lets say the cloth object is meant to somehow follow the movement of a master object but also should react to some forces. Or in other words: object is moving fast = animation state; object suddenly moves very slow = simulation state; objects moves out of the frame again = smoothly go back to follow an animation. The pin to animation attribute isn't allowing 0.5 values or so.
  15. Hi there, I'm trying to control flip particle count per voxel. The idea is to evaluate particle count per voxel on every step (Gas Particle Count) and then analyze the pcount field.. If pcount > n - delete some of particles (pcount - n) to make n numbers. And if pcount < n - add (n-pcount) particles. Any help is highly appreciated. Thanks,
  16. SOP GEO - FIELD FORCE - BULLET

    Hey guys, working on a destruction peice and wanting to take the velocity from my charachter and put it into my bullet sim - So decided to try and use a sop geometry node to bring in the calculated velocity (from a trail and fluid source) - which is working perfect. But my sop force doesnt update each frame, its static - ive tried changing the expression from $T to $F and other things, not sure if its a limitation or if im doing something wrong? i will attatch a file but will be missing the geo but atleast you guys can see the setup Any help would be great! Thanks Destruction_v3_t2.hip
  17. I have three individual components to this briefcase, the body, the handle rings and the handle, the body is a static objects and the other two are RBD packed objects, all concave. I am trying to get the handle to hang from the suitcase naturally but they are falling through each other, there is a slight reaction but i cant get them to completely react to each other. I have attached a zip of the three .obj files and the .hip file if anybody could have a look. Any help would be really appreciated ! Thanks! Assets.zip
  18. Zero gravity FLIP Sim

    Basically I have a 'liquid metal sphere' that floats up in zero gravity and starts to peel off using a flip solver and reveals the solid metal sphere underneath as everything peels away with a paint like viscosity. I have it all working EXCEPT for when the FLIP sphere and collider move upwards (because of the animation i want it to look like zero gravity) it leaves a trail behind it kinda like where it starts the sim, ' I want to have it all move upowards and then the gravity starts to peel off the 'paint' from the collider sphere Thanks for any suggestions also attached an example file ZeroG_test.hiplc
  19. I have a load of RBD packed objects smashing on a Ground Plane, they're all intersecting by a consistent distance through the Ground Plane, the RBD packed objects are all convex hull rather than concave although changing between the two doesn't seem to make a difference. I've tried replacing the Ground Plane with a static box and trying different geo representations on it but that doesn't seem to work either. Any suggestions on how to fix this would be really appreciated! Thanks
  20. I have two separate stacks of geo made using copySOP's, i am trying to get them to interact with each other. They do interact with each other but the constrains only effect one model, i can switch them in the merge but its only ever one that holds together, the other falls apart instantly no matter what the glue strength is. Ive put photos below and attached the scene file with the model that needs referencing in. New to Houdini so any help or advise would be greatly appreciated! Thanks PlateSimulationTest001.hipnc plate.obj
  21. I Have stacks of plates and bowls that i made with a copy node on one original model of each type of plate or bowl rather than importing each model multiple times. I want each object to be able to fall and smash independently which i am struggling to work out. When i make the stack a RBD Glued Object it either all moves and smashes the exact same way like they are being read as one whole piece rather than individual plates/bowls or they move individually but the glue errors saying "making objects from different solvers mutual affectors" so they cant smash. Sorry if this is a basic question i am new to Houdini, any help would be greatly appreciated!
  22. i have managed to create a network of masked gravity force to drive the RBD packed objects but I'm a little confused about how to proceed further. i need to control the moving pieces of geometry more effectively with further forces as well as create debris from the cracks or where it fractures. any direct help (i have attached an example file) or pointing me towards resources where i can learn further would be cordially appreciated. thank you and best regards fracture.avi fracturingGeoMaskingForce.hipnc
  23. RBS SIM

    Hi ,i use Houdini apprentice 15.5 for 3 months now and i have a problem with the RBD collision.In fact, i'm doing and exercice and the goal of the exercice is to have realistic mouvement when the tube push and object on the table. But the collision of the RBD Objects with the ground is not realistic. The thing is watch tutorials and i reproduce in an empty scene the tuto and it works fine with a simple object like a table and a cube, i mean when the cube is put onto the table the cube does not pass through the table. But in the scene you see bellow everything was working fine until I apply the glue node onto the bowl. After that the bowl the dinner plate and the waterglas pass through the table and it is the first issue i have.Secondly when the objects fall onto the ground the collision is not realistic.I need some one help to fix this problems.Thanks you
  24. Running a fluid sim over geometry

    Hello! I was wondering if anyone knows a way to run a flip simulation over specific geometry. The closest visual reference I can think of would be the workflow from Moana. Would you have to turn the geometry in to a fluid object, or is there some way to have the simulation run on top of the geometry?
  25. Cloth sim for sails

    Hey guys, I'm struggling with the fem solver. Basically I would like to create a realistic looking cloth sim for the sails of a ship. Unfortunately I just can't get it to look right. The wind force deforms the object like animated noise insteat of adding variable velocity. I fit01ed nearly every parameter on the wind force or uniform force but it keeps looking like jiggly gum, not like cloth floating in the air. Can anyone show me an easy example on how to achieve something like this? https://vimeo.com/136480165 [vimeo.com]this is how my gum looks like: https://vimeo.com/197677800 [vimeo.com]Thanks!
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