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Found 401 results

  1. Hello, i'm currently working on a project where i did a sand simulation. That worked. But now i only want to see the top plane of the simulation, so that i can place it my video footage. The Sand is placed in a box and then a character comes through it and some of the sand goes up. Now i want that at a certain y-value the sand is not visible anymore and i can place it in my footage. I hope someone can help me;)
  2. Dear all, Plz give me some suggestions to do simulation of talcum powder as I shown in attached reference gif. Thanks in advance..
  3. Animating a Spring Constraint

    I'm trying to get these two objects to move towards each other after they hit the ground. Blend solvers are being used to allow the objects to transition between their keyframed positions and dynamic states and I need to add an attractive force which is what the spring constraint is supposed to be for. If I plug it in and doing nothing to it outside of hooking up the constrained object and the goal object it works fine. However, I want to control the timing of it so it can work it into an animation. When I tried to keyframe the spring strength or activation parameters the constraint would stop working or not work properly. Result from keyframing the activation parameter. The objects do not pull towards each other, the constraint just keeps them in place. Node network Does anyone know why this is happening? Thanks in advance!
  4. I need to reuse the constraint polylines from an RBD sim after the simulation is done (to create visible geomerty for rendering) but the only geo I can find is the constraint's initial state and the rbd geometry itself. It doesn't look like the polylines are kept at all. How can I reconstruct the simulated constraint lines between rbd pieces to use downstream in the network?
  5. Hello guys, In a simple RBD simulation, when I replace the "Ground Plane" collision DOP with my Collision-Box, the rigid body objects never stop moving! How can I bring them to stop? (When I use the "Ground Plane" node, everything is ok!). I tried to use the " rbdautofreeze DOP", but it doesn't work. Thanks for helping. RBDs_01.hip
  6. Hello, My aim is to be able to recreate an explosion made of objects (in this case pills), which collide with each other and move away and float without gravity in the opposite direction from the central point of origin "of the explosion. Does anyone have any idea how to recreate this effect? My thought was to simulate an explosion or growth effect and then replace the latter with an instance of objects. Any help would be welcome thank you very much in advance!
  7. Hello guys, As you know, the default attribute value of "Density" in Flip-Fluid is 1000. Now, in a simulation with two amounts of "Densities" (e.g 1000 and 100), what is the best way to speed up the rising speed of low-density fluid particles? I want to force them to reach the fluid surface as fast as possible (maybe something like the buoyancy parameter, in the pyro solver). Thanks for helping.
  8. The gist of the effect I need done is this. I need this Logo to start out fractured into a ton of pieces and off screen in all directions then I need the pieces to kindof suction in towards the screen center where they come together to form the full logo My current workflow is basically run the sim backwards (the logo starts off fully formed and i explode it outwards, then reverse the RBD sim) The problem when I reverse the sim I get a very harsh stop on each piece once the piece gets to its start pose I fix this sort of by running a jiggle or lag CHOP motion effect over the points after i reverse the sim, adding some overshoot to the sim so it overshoots the rest pose and then settles back into the rest pose the issue is now i get intersections with the pieces. Was hoping someone might know how i could maybe run another simulation on top of the reversed sim? Like have it follow the same motion but adjust for self collisions?
  9. Tree Simulation

    Hi! First, I would like to say that I have a very basic knowledge of the program's tools, I have a very superficial knowledge of the whole. Maybe I don't really have the ability to do what I want yet but I decided to ask for help here! My intention is to make a tree simulation using Lsystem and 3 more leaves that I developed, I have some doubts in this whole process. I'll start with the part I got with the help of the forum, I managed to do the trunk simulation with the following formula: After that I developed 3 types of leafs with the following formula: What is my problem: within Lsystem I developed rules that have these leafs in the size, angle and places I want. But when I simulate the trunk they distort and the trunk is no longer stuck in its pin group, besides all the leaves don't turn into a mesh, even using a convert node they "break" when the simulation occurs. So my real problem would be not being able to transform them into solid material and then not being able to use them within Lsystem in the simulation, with their rules. I know that maybe it's very complex to help me with all this but if anyone can give me some light, pass a tutorial that addresses the topic in general I would be very grateful! I'll leave the file here too. planta2.hip
  10. Dop I/O vs Dop Import

    I am working on a pyro sim in which i have cached every frame as a .sim file. These are very large, so ive been researching ways to cache the frames more efficiently. This led me to using the Dop I/O to cache out much smaller .bgeo.sc files. I am aware that this enables me to select which fields i want to omit from the cache, hence the lighter files. The problem im having is that when it comes to rendering (using Redshift fyi), the loaded frame from my .sim looks very different to the loaded frame from my .bgeo.sc, even when i include all the fields from the original DOP network in the cache and it is same size as the equivalent .sim (i presume it contains the same amount of information?) From what i can tell the Dop I/O and the Dop Import are both fetching the same information from the DOP network, so why do they look so different when it comes to render time? Hope all this make sense and i appreciate any responses, cheers!
  11. How to combine vellum and rigid body?

    Hello, I have a scene where I have a bunch of USB cables swaying in the wind, naturally only the cables bend, fold and sway, not the USB head themselves. So I was wondering if it was possible to have the USB heads be rigid bodies, so that they still interact with everything while retaining its shape. Thanks! vellum.hip
  12. Cost of simulation

    I'm a freelancer, I wanted to know how much is the cost of 1 minute simulation, I need a general answer. I know it depends on the type of simulation , and the complexity. But I want to have a price in my mind and then decide for my future projects.
  13. Hi guys, I filled half of a tube with some fluid particles. The problem is that fluid begins some weird motions. How can I fix it? Thanks for helping. Fluid_Test_01.hip
  14. I have some fracturing happening in a sop solver inside a dopnet on a simple booled piece of geo. I have the fractures working on the geo over time and all is good. The problem I'm getting right now is the bool is failing. It works as expected if I add a fracture to the geo before the dopnet, but I want the fracture to only happen in the sop solver using the conditions in there. Is it something with groups on the assemble node? or the boolean itself?
  15. Dop import not working

    Helllo, I am new to houdini and trying to experiment with rbd but I fail to use the dop import node properly. I am trying to fetch the geometry of the dopnet inside an sopsolver. What am I doing wrong ? Thanks in advance.
  16. Vellum Pin to Target with gravity

    Hey gang, I've run into a problem I can't get my head around. I have a Vellum cloth sim with a Pin to target constraint. I want the cloth sim to follow the target while also being effected by gravity and can't resolve making both the target cloth sim and gravity occur at the same time. Any insight would be MASSIVE help! Thanks. Hip is attached. Vel_pin_target_gravity.hiplc
  17. Hey everyone! This is my first post here! I have a scene where I'm caching a vellum grains simulation to a disk cache. I'm having trouble understanding why it takes so long. When I cache the simulation to ram in the viewport each frame takes about 15 seconds, however when I drop a File Cache SOP and save it to my hard drive each frame seems to take about 3 minutes. Could someone explain why this may be? I have tried saving to another drive and it didn't help.
  18. Hi, I'm starting learning houdini and really excited. I'm in still learning phase and searching ideas to do. So here is my problem. I have idea for connect two cables with a cable supported collision and simulation result. question 1: can i generate simulation result on parameter change. (i don't need whole simulation frames just need simulation result) question 2: i need generate cable(between two cables ) "according to grid collision" and "affected with gravity". so i'm newbie and just created with "add" sop and seems really bad. wires.hipnc file attached for review. I need advice and/or guidance. Thanks in advance. wires.hipnc
  19. How to export vdb's in the right way

    Hello, I have a massive smoke simulation going on, and now I want to export this simulation in vdb's, to import them into a another 3d software (Blender). But when I click on the cache button or render to disk button, everything goes well, until frame 70 +-10 frames or so.. and then it stops because I am getting out or RAM. As I have 64 GB RAM, I would love if someone could explain me, how can I export the whole simulation, without decreasing the smoke division size... or smoke quality! I have tried to just export the density field, but then the smoke looks kinda low res and only if I am exporting ALL pyro fields, like: density, temperature, fuel, vel x, vel z, vel y.... and so on, then the smoke is high-res in Blender. But if I am exporting all fields, then it stops after frame 70 because of the RAM... is it possible to cut this simulation in parts and exporting them seperatly or somehow optimizing the fields or the pyro sim or vdb's so that I can export the whole simulation without any problems AND in high-res quality? Thanks for advance Daniel
  20. Vellum - Sponge/Foam behaviour

    Hey Guys, For the past two days I have been trying to recreate this shot in vellum (Starts at 7 Seconds): But I cant seem to get it close! First I tried just squeezing strut softbodies with geometry but I could not get them to stay in place or have the right behaviour, then I went the inflation route witch also did not work since foam does not inflate like a baloon and generally keeps its shape. I thought I had found the solution with a vellum rest blend, blending between the original and the scaled up geo (I attatched the file), wich kinda worked but I could not get it to behave like the video. If you guys have any Idea how to achive this It would be greatly appreciated! foam_squish_V01.hiplc
  21. Hello all! I'm very new to this forum but I'll try to pose my question as clear as possible. Let me know tho if anything doesn't make sense. I have animated a raspberry falling into some milk. On that raspberry, I have those little brown-yellowish hairs sticking out (called stigma as I learned from Entagma). I've generated them with a Guide Groom and a HairGen Node and I have some adjustments on bend, frizz and stuff in the Guide Groom which I'd like to keep (so Bypass Editable SOP Network is not an option). I want to prevent them from being simulated like hair each frame. Best would be if they could be generated on frame 1 and then just stay exactly as they are, simply moving along with the animated geo but without deforming. Hopefully this is even possible with a hair sim. (btw: i've already fixed the scattering of the hair using the uv attribute so at least they're not jumping around) Thanks for any help in advance!
  22. I stumbled over a problem with the transform pieces SOP when i use a timeshift between two simulations. In my setup i simulate the pieces with a rigidbodysolver, extract the points with dopimport, transfer the pieces onto those points and simulate over the pieces again. And the final step is a transform pieces. This works fine, as long as there is no timeshift between the two simulations. When i introduce a timeshift, the transform pieces SOP places the pieces nowhere near the extracted points. nested-sim-timeshift-2.hipnc
  23. Houdini.School Velocity Forces

    I am happy to announce that https://www.houdini.school has launched and you can get 15% off now through July 27th, 2021. I'll be joining a host of talented Houdini teachers, like: Debra Isaac Kate Xagoraris Beck Selmes Christopher Rutledge Justin Dykhouse Jeffy Mathew Philip Nicholas Ralabate You can learn more about my Velocity Forces class here: https://bit.ly/houdinivelocityforces Teaser video for my Velocity Forces live class: https://vimeo.com/577928177
  24. Hello! This is my first time posting here. I am a graduate student currently working on a project that involves a character comprised of rigid objects that can assemble, disassemble, and rearrange itself. The parts can also blend between dynamic and keyframed states. I have a method for the state switching, but I cannot seem to find away to apply any attractive or guiding forces to the parts when they are in their dynamic state. I found a way to do this previously by using a POP Attract node, but it only worked with Rigid Body Solver. I'm not sure how to apply that same node to a RBD Solver. If any knows how to make that work or knows a better method, I'd appreciate it. The goal in this test is to make the ball roll towards the cube and fit into one of the sockets. I have attached a zip file with the assets and .hip file. Thanks in advanced! RBDTesting.zip
  25. Hi, I'm considering updating my local ethernet LAN to a 10 gig ethernet lan. Right now, I'm on an old 100Mbps LAN and it's too slow to playback simulation caches over the network. I've been seeing that people are using 10 gig networking at home now and are able to play back video, do video editing over the network with it. I'm wondering, if anyone is doing this, how is simulating to cache files, reading/writing cache files, on a 10 gig local network? Is it like working on a local machine?
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