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Found 305 results

  1. Hello Houdini Magicians, This little bit of code is, according to the performance monitor and some debugging, slowing down my simulation... alot. Specially with a high number of particles. The nPt comes from the nearpoint function. I analyzed the performance impact of the nearpoint function with many particles and it is not significant. Its the conditions and moving/removing particles from groups. What is the optimal way to do this?
  2. Hey all, it's first post here and new to Houdini so I appologise if this isnt the easiest to follow. I have been trying to create a robust system for controlling vornoi fracture points, their glue strength and a way of manually breaking constraints between points. Ive been following some tutorials piecing together relevant bits from each to try and achieve this. My current issue Im facing is that once I play the simulation and the constraints start breaking they start flickering back on and glueing parts of the object which have already been broken. From my undertanding I think the manual breaking of constraints which is conflicting with the remove_broken SOP solver within DOPs, but I can't figure out how to get them both to work together. Any help would be greatly appreciated as I've hit a brick wall with this. Ive provided my scene file - I hope it's all easy to undertand. Thanks. Fracture_v001_notworking.hiplc
  3. Hey guys, trying to figure out something that's probably simple (I hope). I'm making a small edit to the sopsolver inside a POP source object. Just adding a wrangle to ignore some points, sometimes. Specifically, per substep. Unfortunately I can't figure out how to get the substep number from my wrangle. To recap, I have added an extra wrangle into the SOP Solver inside a POP Source node. Trying to access what substep the sim is on, and @SimFrame doesn't work (which makes sense). How should I do this? Thanks, -M.
  4. Forest Fire

    Forest Fire entirely done using Houdini and Rendering in Arnold.
  5. 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
  6. PYRO HELP

    Hi everyone. I've really given up and this is my last hope. I've looked everywhere for a month now and can only find basic "billowy smoke" tuts and pyro fundamental classes but my brain can't register how to make a certain look. All I want is to create this atmospheric wispy slow smoke like the example I've linked from Simon Holmedals work. My scene consists of a fragrance bottle and I want the smoke to crawl across the screen and bump against the bottle at a slow pace like simon has done in this video. SIMONS EXAMPLE MY SCENE SO FAR WITHOUT THE SMOKE All I need is a simple smoke setup like simons and I am struggling to achieve this result. Whenver I try I get clumpy results that tend to dissipate way too fast and just has a horrible movement all together. I'll also attach my .HIP file for anyone who wants to take a further look at my sim setup so far. I feel like I am not utilising the tool correctly and would love ANY input LINK TO .HIP FILE Thankyou.
  7. 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.
  8. vellum blend(inflate objet)

    Hi all Im testing vellum blend for a personal work . I have attached a file where I inflate a torus and a pighead. I need to do it with a rest position so I have used a vellum blend to control of how start the geo animation and how it ends. With the torus works very well but if i use the pigheadtest is not working as expected. Torus and pighead has almost same size, points, and primitives. Is the pighead not working as expected because of the shape of the geo?? This is my question. If I apply a polyreduce to the pighead I start to get accurate results, but the things is that I want to do it with a high poly car model, so I would like avoid polyreduce to get good results. I have noticed that with high poly models is almost impossible to inflate using this method. Also Im trying to inflate by areas, I mean, per example inflate first the head of the pig and then the ears, in a gradual way. Can any one point me the right direction with this?? Thanks a lot for any help my friends inflating_test.hip
  9. Greetings, I'm currently working on a large scale FLIP animation and I'm running into a question, I need to fill with liquid a very large object (like a house), and I figure that the divergence was doing a great fob until I reduce my particle separation for a higher definition. Sim look different, but that it's fine. The main problems is the volume that doesn't fill anymore, so is there any kind of equation or technique that I can apply to ensure the same result persist over particle separation. Any advice is welcome I made a video of the difference using the same divergence value over time Thanks for your time
  10. Waterfall Bending VFX breakdown from 哪吒 (NeZha). I was responsible for all the FX and rendering FX elements. All the FX are created in Houdini and render in Houdini Mantra, final composite done in Nuke.
  11. Cloud tornado with water VFX breakdown from Chinese feature 哪吒 (NeZha), I was responsible for creating and rendering of all the effects using Houdini Pyro and Flip, render in Mantra.
  12. Flip Fuid Volume Loss

    Greetings, I'm doing a basic flip simulation where I fill a cup with liquid and then I rotate the cup to spill the liquid into another cup. Sounds super easy and basic, but after some time fine-tuning the collisions and the liquid I can say with certainty that my liquid volume is getting less and less like my particles are dying or sucked into the geometry. A searched a lot for a solution, like changing the Scale of the scene, or lowering the Grid-Scale ( CG Wiki ), or change the collisions but nothing really helps at all. thank you in regards
  13. Object Propulsion

    I'm trying to recreate the effect of small pieces of dry ice propelling themselves across the surface of water. First step was to figure out the propulsion. Thought I'd post my solution in case anyone was interested. The basic approach is to take a number of points on the surface of an object and use their normals as propulsion vectors to move and rotate the object in a (somewhat) physically accurate way. The points and normals can vary over time to create more random behaviour. This can probably be incorporated into dops somehow but haven't looked at that yet. It is also entirely likely that this is trivial to do in some other way and I've wasted my time. If so, please let me know. mt__propulsion__1_0.hdalc
  14. Hey everyone! I have a simple hiRes flip simulation with a boat, but I can't mesh it properly. On random frames the middle part is disappears, and I have no idea why. I managed to figure it out it's somehow coming from the Flattening Geometry option but I couldn't solve the problem. Do you have any ideas?
  15. Hello, I have a particle simulation in Houdini that I exported in a .bgeo sequence and collapsed into a Digital Asset. I import it in Maya using the Houdini Engine plugin, which allows me to load the .bgeo sequence. After shading, my particles are visible both in the viewport and in the Arnold Render View. Everything looks good. But when I try to render them using Render Sequence, they disappear. Same thing for Batch Render. I've tried looking through all the AOVs, using render layers, but my particles just won't render. Is there anything I'm doing wrong? Is the problem coming from the way I export my particles in Houdini, or from Arnold itself? Thanks in advance.
  16. Hi, I'm trying to use a pyro sim to make some realistic clouds and to get the effect I want I need varying levels of dissipation, turbulence, and disturbance at different heights. I've set up some scalar fields and made a gas wrangle to have the gradients I want set up but I can't manage to get them to properly affect the gas nodes. CloudSimming.hip
  17. Growth Systems

    I originally made a post in in the WIP section, but have finalised a selection of images that demonstrate the extent of the project at this particular time. Hope to get some tips, speculation and direction . The work started with an idea of looking into systems of growth and the procedural simulation of that growth. The question of landscape surveillance and 'fertility' arose - can a landscape (or object) topology be evaluated for growth? In this case the landscape would be a scanned model of a terrain, converted from pointcloud to mesh data and thus reinterpreted as a topology of points and primitives with certain inherent attributes: Position (vector), Normals (vector), and curvature (scalar) predominantly. The simulation can then search for 'flatness' and eliminate areas of surface beyond a limit of acceptability. The surface is then displaced whilst maintaining ties to the remainder, this seemed to mirror a process not too dissimilar to inflation (although much more noisy and undefined), always using the retopologised mesh (and thus recalculated attributes) as a driver for the next frame of growth. Generated or grown form is evaluated through a series of spatial explorations with particular functional characteristics in mind. Much like a single-surface-landscape produces the massing for proposed architectural volumes, these volumes are then reinterpreted as single-surface forms that morph into a typology of architecture defined by certain rules. The primary purpose of the interior volume is to house the program of an architecture. The height of the form is predetermined in the procedural algorithm of massing to produce volumes within a range of heights (for example between 3 and 20 meters). The nature of the form suggests an architectural language of evaluated skin as a means of facilitating architectural space. This is then differentiated to provide for the various requirements of a space of production - for example: how can the floor surface serve as a platform for plant growth; how can the side envelope serve as a mediator of thermal comfort; etc? A. There is a desired differentiation between roof and side envelope - key factors to be considered are the issues of transparency in form for light to enter the space below and the capacity to drain rainwater or melting snow. B. An impression of uniformly distributed structural frames is suggested as a method of holding up a dressing of skin not too dissimilar to ideas of bone to muscle tissue connections. C. The form is interpreted as a skin multi-functional, multi-material character. There is a desire for a thermal envelope mixed with porous characteristics that allow for breathability within the interior environment, light, and mediation from the harsh external environment. The following images are all excerpts of a fully procedural exercise; all grown; but in various stages of development of the same system.
  18. I want to make water from the hose. Like a fire truck, very strong and fast. I tried to use a popslover, but it didn't look goodon the colision side and it didn't speed up properly when I tried to use flip Solver. I tried to bring the location and speed of the particle to flip Solver but it didn't work. What should I do? I'd appreciate it if you could help me. thank you
  19. Hello, I have noticed something interesting which I don't understand, but maybe somebody out there does. I created a Wave Tank shelf tool then a sphere and I hit the Deforming Object shelf on the sphere. Now I'm checking the OUT_INITIAL_VELOCITY node with PointsFromVolume and volumeTrail nodes. When I wire the collision geo into the collision input of the OceanSource node the velocity is become wierd as you can see, and it affects on the simulation in a bad way. It's just shelf tool! I didn't make any changes. I use 17.0. Is it normal or is it a bug or what is it? Is there anybody, who knows it?
  20. Hair initial state

    Hi everyone, im new to houdini but have a question as i really cant seem to find the answer anywhere. I was wondering how you would keep a groom once you have added simulation to it? As in how do you stop the groom from just flopping down with gravity? Is there a way that the simulation will try keep the groom ? hope this makes sense. Thanks in advance.
  21. Hi, thought I'd share this in this section too: I wrote an article for the german “Digital Production” magazine about my free LYNX VFX toolset. For the article I made a couple of renderings using the LYNX fabric tools. Luckily it even made the cover Here are my personal favorites, the rest of the images can be found on Artstation. You can also find the complete scene on GitHub under the Demo Files. So now anyone can design an ugly Christmas Sweater;) Looking forward to seeing what you guys come up with, enjoy! Links: LYNX VFX Toolset Odforce Thread: https://forums.odforce.net/topic/42741-lynx-free-opensource-vfx-pipeline-tools/ LYNX VFX Toolset (Sweater Scene File included): https://github.com/LucaScheller/VFX-LYNX Artstation (HighRes Renderings): https://www.artstation.com/artwork/OyeY6g Digital Production Magazin: https://www.digitalproduction.com/ausgabe/digital-production-01-2020/ Alternatively view the article in my latest blog post: https://www.lucascheller.de/vfx/2019/12/15/ynybp7wpiqtshoy/
  22. Hy guys, I would like to simulate an air bubble inside a rotating bottle.. Results with vellum are not successfull.. Any hint? Thank you.
  23. I started using Houdini about 2 years ago, recently I have felt a desire to not only share but, hopefully to open up a discussion about the explorations undertaken in the work. The first post is therefore a look at how it began. The work started with an idea of looking into systems of growth and the procedural simulation of that growth. The question of landscape surveillance and 'fertility' arose - can a landscape (or object) topology be evaluated for growth? In this case the landscape would be a scanned model of a terrain, converted from pointcloud to mesh data and thus reinterpreted as a topology of points and primitives with certain inherent attributes: Position (vector), Normals (vector), and curvature (scalar) predominantly. The simulation can then search for 'flatness' and eliminate areas of surface beyond a limit of acceptability. The surface is then displaced whilst maintaining ties to the remainder, this seemed to mirror a process not too dissimilar to inflation (although much more noisy and undefined), always using the retopologised mesh (and thus recalculated attributes) as a driver for the next frame of growth. The video and images below are examples of the earliest explorations (and failures) of this theme, first applied to a modelled object, with the video then moving onto a landscape: https://vimeo.com/376861116
  24. Hair Guide Transfer Issues

    Hey guys, I'm still fairly new to Houdini and I am trying to make a hair sim for a character on a short film I'm on. I have created my groom on a static mesh of the character and I want to transfer it to the animated mesh. I've imported an alembic cache from Maya, matched topologies with the static mesh, cached that matched mesh out, then brought it back in. I want to transfer the guides to this newly cached mesh, but when I use the guide transfer node, it creates multiple instances of my groom and scatters them around the space. I have also tried the vellum constraint option "attach to geometry" with only the root points selected, hoping the rest of the curves will follow but only the root points moved. Not only that, but they didn't spread across the mesh to their correct position. At this point, I'm not really sure what to do anymore. Any recommendations are welcome. I can attach the file too but I'm not sure if that would be much use since you would need the cache files too.
  25. Tree Rig / Asset + Tree Sample Now In Patreon I happy to share one of my latest houdini digital assets , Tree Rig . the idea came from simulating tree with pyro to make a photorealstic look Patreon Link : https://www.patreon.com/posts/31800923 Viemo Links : https://vimeo.com/356351056 py Tool + asset : https://vimeo.com/322402973 Stadningmanpage : https://www.facebook.com/standingmanfx
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