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Found 317 results

  1. I have a simple problem, but do not know hou to do it. I want to color my sphere with created vector attributes, and let it change frame by frame based on the points of color vector I created as shown in the geometry spreadsheet. It should be easy to do? But I am a newbie, have tried many ways but failed. Thanks a lot!
  2. Upres external simulation

    Is ist possible to make a simulation in embergen, export as vdb, import into houdini, and upres the simulation using gas upres? (you have density, temperature, vel, fuel and heat)
  3. Hi everyone! I'm currently going through the Procedural Cities in Houdini Tutorial from Pluralsight. So far everything worked out great. I had to adjust some nodes (As the tutorial was made in Houdini 15) But it's working. I'm now in the process of aligning bounding boxes of Buildings to the geometry surrounding them (e.g. rotating the buildings so they face the streets) Using a bulletsolver and popattract. In the tutorial video this simulation runs smoothly... when I'm opening the exercise files on my Computer it runs fine too. But with my own file the viewport runs slow (like 1 frame every second) The perfomance monitor shows this: (The dopimport took even more time but I bypassed it here to see if the problem was somewhere else) I'm not sure where to check for the __DopDetailLook_Guide or how to influence it. But it seems to be viewpoert related, as entering a framenumber in the timeline simulates super quick and gives the right result... So this isn't really breaking anything as I can get the correct result anyways without waiting forever, still I would love to know why the simulation runs so poorly in the viewport. If anyone wants to see the hipnc file I'm happy to upload it somewhere. Any help would be greatly appreciated! Cheers! Daniel
  4. Hi guys! I started houdini 3 month ago so sorry if my question is dumb but I'm really stuck on a problem for 2 hours now: I want to export an .obj file from a simulation (just one frame of the sim), so I tried many different ways: rop geometry, writing file, save the geo folder itself to gallery... But nothing is working and I can't find a way to solve this problem! I searched on the internet and there's almost no one speaking about that... Btw I'm using the apprentice version of Houdini so I can't use alembic files... I give u my project file so u can see more clearly what's going on. Thanks for helping Chain.hipnc
  5. object scale change, durring rbd sim

    Hello, Houdini folks! I have a question about very essential thing durring the rbd simulation. (Im attaching the file here). What I have, I want to change the scale of the pighead, durring the simulation, but without this "strange jumping" behaviour. Any suggestions, how to solve? Thank you so much. strange_behavior.hip
  6. I'm looking for alternative workflows for defining attributes on a tet mesh for FEM simulation. Normally I would use intersecting volumes to define regions inside a tet mesh. But for my current purposes that would require producing some pretty complex geometry. The ability to paint these attributes would be simpler. For instance, it might be nice to be able to paint an attribute on the surface and have it penetrate the tet points at a given depth. (Though even if that were possible, I'm not sure how you would access deeply interior points that are not close enough to the surface.) What methods do you use for assigning attributes to a tet mesh?
  7. I am trying to render a simulation done with a flip which is made up of 22 million particles. After having made several attempts the houdini console throws me a: 9576: Fatal error: Segmentation fault Saving application data to .... Here below I leave the image and the project files in case someone is willing to help me. Thank you so much!! Help me please!!! Collider.obj Test.hipnc
  8. Hello! I'm following this tutorial: and have been getting similar results up until around 22:10, when my simulation behaves entirely differently. My worm just goes flying. I've messed around with the values in the set_force attribute wrangle inside the sop solver, but can't seem to get anything like what he is. Obviously it's working to some extent, because a force is being created. I'm pretty sure I did everything the same as him... can anybody help me out? Here's my file:Larva2.hipnc
  9. Vellum + other simulation (rbd)

    Hi all, I am trying to figure out a way to let a vellum simulation interact with other simulations. In this case I want the vellum donut to collide with the chain simulation I made. My thinking was to do this through a dop import field. However there is no collision between the 2 simulations. Does anybody know how to achieve this interaction? Cheers! Chain+vellum.hiplc
  10. Hi everyone, I am trying to get an animated collider to contain the smoke I am emmiting inside a tube. I am deleting some polygons over time to let the smoke gradually escape from my tube. The problem is my geometry collider doesn't update even if I turn on "use deforming geometry". So I just have smoke inside my container, but nothing go out from it. If someone hasa clue it could be awesome <3 (you can find the hip file in the post) Thanks Smoke_Animated_Collider.hip
  11. hello guys! I have a pop sim that runs for like 30 frames as they fall .. then I want to revert(attract?!) them back to their initial position (as they were before falling)... I tried the per point attract on the attract node.. and I get their positions back .. how can I get their orientation also to be targeted to the initial orientation?
  12. Hi everybody! I'm new to Houdini and I'm using my time during the lock down to go deeper into it. I have been trying some different vellum sims and I was feeling ready to try a new one. I just wanted to make a new r&d project where a sphere passes through a torus or a hole. I found this example online. At second 15 you see what I mean. https://www.stashmedia.tv/digital-design-days-trailer-ditroit-directors-cut/ Is it possible in achieving this shot in a single simulation or in your opinion it was made with FEM in two different settings and then edit like a single shot? Please let me know I'm dying trying how to do it
  13. 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?
  14. 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
  15. 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.
  16. Forest Fire

    Forest Fire entirely done using Houdini and Rendering in Arnold.
  17. 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
  18. 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.
  19. 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.
  20. 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
  21. 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
  22. 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.
  23. 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.
  24. 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
  25. 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
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