Jump to content

Search the Community

Showing results for tags 'dynamics'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • General
    • Lounge/General chat
    • Education
    • Jobs
    • Marketplace
  • Houdini
    • General Houdini Questions
    • Effects
    • Modeling
    • Animation & Rigging
    • Lighting & Rendering
    • Compositing
    • Games
    • Tools (HDA's etc.)
  • Coders Corner
    • HDK : Houdini Development Kit
    • Scripting
    • Shaders
  • Art and Challenges
    • Finished Work
    • Work in Progress
    • VFX Challenge
    • Effects Challenge Archive
  • Systems and Other Applications
    • Other 3d Packages
    • Operating Systems
    • Hardware
    • Pipeline
  • od|force
    • Feedback, Suggestions, Bugs

Found 110 results

  1. point clustering in DOP

    I scatter points on a surface and then bring them into a DOP network to do some dynamics. I would like to create clusters for some of the particles, to get bigger chunks at some parts, rather than individual points. Initially I tried to pack some of them before bringing them into DOP, but it seems that the popsource1 node removes any primitive data, so no packed geo are coming out of it. I am not trying to figure out if I could use spring constraints to force some particle groups to stay together. Has anyone done this before? How would I go about combining POP forces and SBD or RBD spring constraints ? thank you georgios
  2. Houdini Multi-Dynamics

    Hi guys, We've just launched a new course - Houdini Multi Dynamics. It is focused on solving non-trivial dynamic problems. We’re mastering the knowledge creating FX-assets using virtually the entire selection of solvers available to HOUDINI, in most cases in combination with each other. You can find more details and video on the page of course.
  3. POPS Geo wrapping from DOPS?

    I'm new to Houdini but I know that when version 13 came out, POPS AND DOPS were merged into Dynamics. For the life of me, I can't figure out how to make particles into geo shapes. I'm not trying to create POP Particles that are then converted into proper rigid bodies. I'm literally just trying to take the POP Particles and add a shape to them. So yes, there will be intersections between the particle shape and collision geo. I attached my file. I could get the particle to be wrapped/meshed as spheres if I did use a copy sop on both a sphere and a POP setup. But trying to have those particles collide with other geo wasn't working. If I'm being confusing - in the most basic form, I just want the colliding particles to be meshed as a sphere. Those spheres don't need to be collision accurate, they just need to wrap the particles. Thank you so much for any help! Best, Michael POP_SHAPES.hipnc
  4. Still new to Houdini, but I ran into something interesting(for me) when I was trying to just take the idea of deleting particles based on their Y value. This seemed to work fine until I turned my points into solids. When I was using points, in my dop network I used a geometry wrangle node with the following condition to kill particles below a certain Y value: if(@P.y<-.25) removepoint(0, @ptnum); Now, when I try this with baked geometry that has been converted to solids and using a finite element solver, I can't seem to get the same results. This is where I'm lost. I'm assuming, it's because the solids are now no longer points. But I don't know how to access them for deletion. I attached a file with a simple setup if you're curious to take a look. I'm just taking the idea of deleting objects based on Y height and applying it across the board with all solver/object types. Any help is much appreciated! Best, Stark pointScatter.hipnc
  5. Pin Constraint

    Hi, I'm trying to get my head around constraints. I'm trying to create a pin constraint. I have constrained a box to a point that I created using the add node. I created a 'name' attribute for both the box and the point with piece0 as a string. Also on the point I have added another attribute with a 'position' constraint type. In the dop network I have a constraint network with a 'hard constraint relationship' as the input, It works when I use the point from the add node to constrain to, but if i switch it out for a packed primitive it doesn't work. is there a way that I can constrain an object to the position of another object. I'm new to Houdini so i'm not really sure what i'm talking about but hopefully that makes sense Thanks! Josh
  6. Plane Crash

    Hi, I'm new to Houdini, I'm trying to figure out how to create dynamics for a plane crash. I've played around with dynamics a little and i can't figure out how to fracture a moving object. I need to create a plane crash and have the wing fracture as it hits the ground and animate to the left Similar to this: Do you guys have any suggestions or tutorials you could direct me to? Thanks a lot!
  7. Realistic ice melting effect

    Hi, I have a project where I want to create a realistic ice melting effect. I am quite new to FLIP fluids, however I read a lot and watched some masterclasses about how the solver works in Houdini. But I still struggle at a lot of areas. Reference for the effect: What I have done currently is played around with the viscosity. Basically I took my geometry and created points out of it, then I an SDF volume from the same geometry and passed attributes the values onto points. So, the inner most points would have the lowest value and going to the surface it would reach 0. I fitted those values from a range like 1,000,000 to 0 and then using a geometry vop in the dop context i just subtract some viscosity from the points at each time step. Here are my low resolution tests: Particles: Meshed: https://www.youtube.com/watch?v=IokJPFoNi5w&feature=youtu.be I got a somewhat decent result, however it looks more like ice cream melting than ice. It feels like the melting is not solid enough. The particles are not holding the shape as ice would. That's how far I got for now. I have a few more ideas, though (haven't tried it yet): 1) Instead of using viscosity I was thinking to start with all the points disabled (not solving) and then gradually activate them. 2) I wanted to try out using pressure, like in this example (they are using realflow): http://https://vimeo.com/13599797 but have no idea how to manipulate the pressure field: I was hoping maybe somebody with more experience would put me on a better track and maybe have more ideas or suggestions on what would be the best way to achieve this result. Also, maybe you have some suggestions on the shading part? I have some ideas, but I always tend to take the most complicated approaches I am using H15. Thank you in advance
  8. Hello, This might be such a simple question/answer... I'm have animation, done in Maya and the scene scale was set to centimeters. I exported it as an alembic and imported it into Houdini. Now it's massive (or at least in relation to the grid) and I've got to add some effects to it (more specifically, the flat tank for), the trick is that I have to convert the particles/fluid to geometry and export it back to Maya to fit with the rest of the shaders and rendering. Would it be best if I just scale the alembic uniformly down in Houdini and work off of that? (I have parented it to a null and scaled the null to 0.01 and still got kinda weird results). Any insight would be greatly appreciated, thanks.
  9. Hey everyone! I am in the RnD Process of having a bottle filled with water crash to the floor. I have set up the Bottle with Bullet and constraints. Which works fine. Also the FLIP Fluid without Bullet works fine too obviously. Now if I merge the whole stuff the first few frames mostly work well. But the moment the bottle crashes to the floor the Bullet Sim kinda gets horribly explosive. I tried different flip collision method, yet they do not pick up the very thin bottle geometry. Any ideas on how to make this work properly? Or should I just sim both things one after the other? Assuming the water would not have an massive effect on the behaviour of the Glass? Thanks so much for any help in Advance! Hipnc attached. WaterInBottle_003.hipnc
  10. Hi everyone, Im working on a project where I will need to build a lot of wires which will stretch and eventually snap, like pulling steel cables apart or tearing tendons. I am attempting to do this with the fracturing parameters in the wire object but it does not work. Does anybody have an example of being able to break a wire using the wire fracture? Or is it easier for me to just use the pre-cut wire and animate a glue constraint? Any help at all would be great. Thanks! breaking_wire_RND.hip
  11. I am trying to make a waterfall using FLIP fluids and I am having some problems with them. Primarily, currently, I am having issues with one of my particle fields decomposing and vanishing almost completely instead of filling the basin of my waterfall. I have no idea what is causing it. The zip I attached contains my Alembic model for my waterfall basin. waterfallAdditionals.4.hipnc WaterfallStructureSmooth.zip
  12. Hi guys, I have an urgent problem that needs addressing. I am trying to figure out how to mesh the hand model in my scene with the fluid, so it appears as if the hand is morphing from it. I have a posted two images to show you what I mean. For some reason it isn't letting me upload a video. I've converted both into VDBs and used VDB combine with SDF Union. Any help would be greatly appreciated. Thanks!
  13. Hi all, I've been playing around with fluids and have been learning about driving viscosity based on a point attributes. But I've hit a mind wall. Could anyone help me understand how I would go about creating a liquid that has viscosity based on the distance from the surface? Or to be more specific, as it "cools" it becomes more viscous, but it does this from the surface into the middle. So if I were to pierce a hole in the outer skin, liquid would pour out. Basically, gooey middle. Thanks in advance!
  14. I'm just wondering if someone will point me in the right direction as to what I need to research to hack this together. I've included a test .hip file that contains the bones of what I want to do... but without the desired effect. I want the mower to actually force the broken elements up under the mower and spit them out the other end. Any pointers greatly appreciated. lawnMower.hip
  15. vdb fracture vs other fracture type

    I was wondering... Beside the ability to do non-voronoi fracturing.Is there an other advantage of using vdb fracturing? Performance improvement, ease of workflow, stability? I'm not here to complain or criticize anything. I'm just wondering what you boys and girls think, what does you experience taught you. thanks PS: feel free to point me to an other thread if someone already asked this question. bil
  16. Hello All I have a question regarding control of individual pieces of voronoi geometry using some sort of velocity expression.(I am a noob when it comes to expressions so go easy on me) I think this can be implemented using a ForEach within the AutoDOP What I'm trying to achieve is basically this- Once my voronoi pieces leave the main body of geometry I need to scale down the piece to nothing or make it vanish at a set point in the scene. I'm trying to give the pieces the illusion that they are disintegrating. I plan to attach a small emitter to each piece to add to the look. I'm currently using a glue network that is controlled by Cd attribute using a distance threshold on a sphere to delete the glue network when I need to release the pieces from the main body of geometry... anyway rather than babble on I have attached the file to this message so the script can be looked at. The file poc_RESIZE_v2r5(elongated).hipnc is the script where i generated the sky_for_sim.bgeo and the poc_v9r3_elongated(finished_poc_sky).hipnc is the main file where the sim is implemented. Any help with this would be fantastic as my back is well and truly against the wall Cheers C C poc_v9r3_elongated(finished_poc_sky).hipnc poc_RESIZE_v2r5(elongated).hipnc
  17. Drive pyro shader from pyro age

    Hey I've just created some particles, that drives my smokeless flame. And now I want to shade my flame based on the age of the flame, but I have no idea on how to do that. If somebody could put together an example that would be fantastic, or if anybody will explain it to me, please make it as simple to understand as possible, as my brain is about to melt! Thanks a bunch! Cheers, Jonas Jørgensen :-)
  18. Hi guys, I’m new to this forum and to houdini I am working on a setup to fracture a tower consisting of a couple of pillars and platforms. My setup of the pillars basically looks like this: -geo -file -copy -foreach - subnetwork - fracture setup - subnetwork - glue setup -dopimport The goal is to have as many pillars to fracture as I want (on top of each other to form a tower), but the problem is, that if there are more than 1 pillar, the dynamics behave very strange (if one pillar is hit by something all of them react etc...). I think the problem is that the voronoi fracture creates a name attribute for each piece which is used by the dop network, but if there are 2 copies, I have 2 pieces with the same name. Maybe there is a way to name the pieces accordingly to their pillar (like: pillar1_piece01). I've tried using a connectivity node (before the foreach node) to create a attribute "copynumber" but I don't know how I can access it in the voronoi fracture node where the names are set. But this is just my assumption, maybe there is a whole other problem with this setup, but I hope that my problem is understandable and that somebody can help me out
  19. Hi everyone, I'm quite a beginner in Houdini, so maybe someone can help me with this issue. I'm trying to create an erupting volcano with Flip Fluids (the lava, not the smoke), so I modeled a geometry which I'm trying to use as a collision in the DOP network. Now, when I'm trying to use the fluidsource SOP I get some weird artifacts and can't really manage to get a decent collision SDF volume. One thing I've noticed is that the new VDB volume is really fast and gives me a very good result, but even after I've used vdbconvert to convert my VDB to a default houdini volume I couldn't use it as a collision in DOPs using the sourcevolume DOP. (Please check my attached pics.) Are there any tips on how should I handle this problem? Is there a way to make this VDB volume usable by DOPs or ar there some parameters I can tweak that make the fluidsource SOP output a good collision volume? Thank you.
  20. Greetings! First of all, I am new in Houdini. I like it CloudFX very much. And here is my question: how can I simulate an object flying through CloudFX cloud, with trail, hole in cloud etc? It would be great, if you can give me at least direction, where I could find my answers. Thanks!
  21. Hallo! Please help me with modelling Domino. I learn Lesson 11 "Dynamics" in "First Steps Intro" and made 28 Domino objects. Then i made export trough ROP output driver. But i can't make random import these domino-files. I don't know, what variable parameter to use. Alexander Parfentyev parfin@list.ru
  22. reverse rigid dynamics effect

    Hi, I am currently struggling to create reverse rigid dynamic, something like this But instead of cubes, I have a voronoi fracture pieces. I found a way by using attractor but its not accurate and having some problems. Could anyone suggest a good idea to achieve this kind of effect.
  23. Pyro going through the collision geo

    Hi all, I'm having a weird issue. I'm pretty sure it's something trivial but if someone could point me in the right direction I would greatly appreciate. sorry if this was already covered somewhere but I couldn't find any reference. I have a simple scene, a tunnel and an emitter (fireball shelf tool). converted the tunnel to a RDB static object and increased the Uniform division of my collision object. but still I can see some pyro going through the roof??? Any idea? and here is the scene: tunnelCollide.hipnc
  24. Exploding bunch of flowers

    The model's just from a little playing with the copy SOP. There's stamens and polen in there too with the petals. And darn, but the pollen is expensive. https://vimeo.com/71763469
  25. VFX Generalist Reel 2013

    Hi! I'd like to present you my 2013 VFX Reel. Most of the work here was created with houdini and rendered with mantra. Thank you! https://vimeo.com/io...s/vfx-reel-2013