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Found 417 results

  1. Flickering Liquid

    Hi there! I have this melting setup with a POP solver, basically scattering some points onto the original mesh and then melting then and meshing back everything again using "particlefluidsurface". So I have been trying to get rid of this flickering on the mesh, I have over 500k points and I also tried increasing the samples and playing with the particle separation in the "particlefluidsurface" I also tried using "vdbfromparticles" but its more or less the same result. I want to know if there is anything I can do to help reduce the flickering? Any help on this is much appreciated Thanks in advance untitled10.mp4
  2. Free video tutorial can be watched at any of these websites: Fendra Fx Vimeo Side Fx Project file can be purchased at Gumroad here: https://gumroad.com/davidtorno?sort=newest
  3. Free video tutorial can be watched at any of these websites: Fendra Fx Vimeo Side Fx Project file can be purchased at Gumroad here: https://gumroad.com/davidtorno?sort=newest
  4. Group particles with maximum age

    Hey everyone! I got a very silly question, it seems simple but i cant figure it out! I have a Flip sim with reseeding "on", I had to turn it on because of the look i was looking for, so particles are constantly dying and generating overtime. I would like to randomly group those particles that doesn't die until the end (basically their age is maximum) and clone sphere on them, I have age attribute from solver but for some reason values are changing uniformly for all the points! I tried making my own "age" attribute using SOP Solver with @age += @Timeinc and attribute transfer but the results wasn't accurate enough because of "attrib transfer" approximation nature. So, I guess my solution is to group all the particles that are present in the last frame based on "id", keep them and delete the rest of them, I guess gotta do it with Vex using arrays and stuff but I'm a noobie in vex! I know it sound confusing but I appreciate if anyone has a solution for this Thank you
  5. (I have posted on the wrong sub forum, reposting here) Hello everyone. I have been using Houdini to Niagara on several projects for now and it works fine. However i would like to loop some of my sims. I do it with a couple of time remap nodes in Houdini. Of course it doesn't work within Niagara. (the sim ends in the middle, exactly where the "end" of the sim is and the second part is not showing up). I tried to alter a few attributes ( age, life ) with no success. I am wondering if there are intrinsic attributes that should be changed in order for this to work? ( I have attached an example ) let me know if I missed something. thanks! looptoNiagara.hiplc
  6. Free video tutorial can be watched at any of these websites: Fendra Fx Vimeo Side Fx Project file can be purchased at Gumroad here: https://gumroad.com/davidtorno?sort=newest
  7. Heightfield particle collision?

    Hi, I'm extremely new to Houdini and I'm trying to create sand winds like in here: My approach is to create particles (sand grains) that spawn on the heightfield, before being blown by a wind simulation or something (or instead of individual grains, just a smoke simulation) What I have so far is a Procedural desert heightfield. I followed a tutorial to set up a smoke simulation that advects to a pyro,, but I'm struggling with setting up collisions and figuring out how to spawn the smoke/sand procedurally on the heightfield. My pyro sim: My heightfield: Any help would be much appreciated! I can elaborate on any part so I can get advice better.
  8. Hello, I'm brand new to Houdini and have been working on a "shockwave" effect and I have just looked in the Render View and there was only black screen. Then I tried to actually render it but it would still only show a black screen. I've attached some images below to show the issues that I'm having. This is my Network inside of a Geometry. This is how it looks inside Scene View. This is how it looks in the Render / Render View. Here's the project file. Please help me out if you can learning shockwave.hip Thank you.
  9. Hello! I've been using Houdini as a TD for about 2 years now and I just recently got my hands on a C4D and X-Particles license. Playing around with X-Particles it has become apparent that Houdini can make something fairly simple (like particle simulations with constraints) very difficult. For these past 2 years I've been trying to get, specifically, thick liquid like particle constraints (not just viscous but stringy) working in Houdini and I've never been able to get results I can be completely happy with. I've been able to achieve "sticky" effects using vellum grains and vdb meshing before as seen here, however, I was always after a different effect using a particle simulation that was NOT attached to a mesh but still behaved in a similar "sticky" fashion when coming in contact with colliders. After trying this over and over again in Houdini and having unsatisfactory results, I've now experimented with X-Particles and I was a slightly frustrated by all of the time I had spent in Houdini and how simple and quick it was to achieve exactly the effect I wanted in X-Particles. In the video below you can see what effect I was after in XP. I was curious if anyone at all has re-created this stringy liquid effect in Houdini with POPs? It seems clear to me that FLIP fluids are not really the answer for small scale simulations where you want a "stringy" surface tension look. I've gotten close with FLIP and vdb meshing in Houdini, but it never looks as natural and real as X-Particles. I've heard that maybe the POP Fluid node may be the answer (here), but I'm curious if anyone has attempted these stringy constraints in a Houdini project! Any Houdini workflow tips for such an effect would be appreciated because the cost of X-Particles and C4D is not something I plan on paying for the rest of my days!
  10. Free video tutorial can be watched at any of these websites: Fendra Fx Vimeo SideFx Project file can be purchased at Gumroad here: https://gumroad.com/davidtorno?sort=newest
  11. Fluid Along Surface

    Hi Guys, I'm new to Houdini so please, bear with me:) So, what I want to achieve is following: I want to have fluids (or particles, through POP Fluid), that would go up against the gravity (antigravity) along the collision geometry, upwards, along the vectors that are parallel to the surface of geometry. The effect should look like a paint going down on a surface, and covering it, but the direction is reverse, so it goes upwards. The collision geometry is simple, like a sword, thats it. I tried to do it with flip tank, with attraction force, but somehow I couldn't not get the result I was hoping for. Can you please show me the direction I have to follow or an advice I can follow to achieve this result? Is it better to do it through Flip or through particles? Thank you in advance. Cheers, David
  12. Hello everyone, I am a new Houdini Indie user, so i might have missed the obvious. I am exporting a particles explosion from Houdini to Unreal. it works great except for the trail node. It does export the datas ( file is much heavier with trail node) but the trail node is duplicating the particles id ( and probably all the other attributes). Once I import a cache in Niagara, I only see the particles from the POP and not the one from the trail. I tried randomizing the id attribute on a static particle system, and the trails points do appear properly. ( on an animated one it juste pops a random particle every frame). I was looking for a way to either, give the trails points an id or create a trail directly within my popnet. For the second option i basically want to pop a particles every frame with a 1frame life from each points of the simulation... but I cant find how to do that. Do you have any leads to what route to take? thank you!
  13. I'm sure there is a simple answer for this, but it's got me scratching my head... I'm trying to use the @hittime attribute in order to do some stuff with my @pscale, but it never stops growing even after the particles are stopped by the pop collision detect behavior. The @hittotal attribute does the same thing, like they are all vibrating on the surface or something even though they are not moving. I've attached a simple scene. pop_hittime_1.hip
  14. Alrighy, I have a big wedge of stupid in my head that is keeping me from doing this. I have particles emitting into a container (a super-simplified version is attached). I would like to get it where instead of the usual bounce/slide off a wall, the particles slow down and gradually move/are pushed away from the containing walls. I'm assuming this would be done using SDF/volume sample/volume gradient and a POP wrangle modifying the velocity based on the sampled values, but I just can't get it to work. I've seen lots of tutorials on using this approach to get particles to stay NEAR a surface, but my brain isn't adapting that to a nudge-away-from-a-surface instead of a nudge-towards. What am I doing wrong? The POP wrangle code-in-progress (the collider is input 2, the VDB is input 3): float samp = volumesample(2, 0, @P); vector grad = volumegradient(2, 0, @P); @v *= -grad; SOMETHING is happening, just not what I want. (And ideally I could have a second SDF inside the container pushing out, thus gently keeping the particles within a certain radius of the container wall, not going to the center.) Thanks for any help! example.hiplc
  15. fun and play with particles

    having some fun with particles.... birth of a massive star. for my little #astrophysics exploration, i’ve created a star simulation using openCL in houdini. its based on nbody #physics model, only driven by #gravity. using #nvidia #quadro rtx 5000 #arnoldrender. the colours are not quite right, I am trying to integrate kelvin colour temperature. the current colour is based on density and speed. In this simulation, I assumed 48% amount of negative gravity to fill the mystery of dark matter. I used 1 million nbodies for the simulation. for the steps, I am planning to add finer particle streams to get more details. fast particle rendering with path tracer is hard !
  16. This is my first post in the forum, so first things first: Hello everyone!! Down to business: I'm trying to create a custom 3d vector field from a set of imported lines so I can drop some particle tracers on it. I managed to convert the imported lines to vectors using the orient along curve node, and I also created some voxels through bound>volume (ideally one for each of my imported lines, although I'm not sure I succeded). Now, what I want to do, is to link each one of my custom vectors to it's correspondent voxel, so that when a particle is inside that voxel is affected only by that particular vector. This is where I get lost, I don't know how to link my vectors to my voxels... I tried importing my "vec" point attribute inside my volumevop but for the life of me I can't seem to figure it out. I come from Rhino+Grasshopper, so I thought I'd be a bit familiar with the node workflow and all but... wow... Switching to Houdini feels more like stepping off a meek pony and jumping right on top of an untamed pissed off stallion. I'm attaching my files. Any help taming this beast will be much appreciated (Probeta_02_vF_S.igs is the file containing the custom lines) Custom_vField.zip
  17. Fluids - help!

    Hi team! I have followed a good tutorial on Youtube as I was having issues with keeping fluid in a container, this tutorial also shows how to do bubbles in the water ( Tutorial here ) When the bubbles go through the water there is a loss of fluid and I have been playing around a lot trying to figure out how to prevent the loss, when the collision objects aren't connected there is no loss in the amount of fluid but when I connect the Collison object there is a loss of fluid and I cant figure out how to stop that. I was wondering if anyone else happened to know? Its just bothering me and I wanted to know the answer. Cheers! Hottub.hipnc
  18. Using Engine I have been able to import a particle cache into Maya just fine. Scale and color came through and were easily applied in Arnold. However, I need to recache the particles as a Maya nParticle cache to hand it off to someone else not using Houdini Engine. I can get it to cache the general position/lifespan, but it doesn't appear that any color/scale(radiusPP)/alpha(/transparency) information is in the re-cache. How can I make sure those attributes make it through to the nParticles (re)cache? Thanks for any help!
  19. Redshift instances shaders

    Hey guys, i have a question regarding redshift instances on high particle counts stuff rendered with redshift: Everything is working well with a "s@instance=..." wrangle. Then if i try to get the Cd attribute to change the instances/particles color it get super slow, is it a normal behavior or is it somehow a way to avoid it/doing it more efficiently ? For example if i don't use instances but standard redshift particles, even with changing the Cd in the shader it is super fast, it only happens when instancing.
  20. In a pipeline that requires you to do VFX work in Houdini and then render said VFX in 3ds max, there are many formats that are viable (I mostly use alembic). But I was not lucky finding a straightforward method/format to export particle systems that were created in Houdini to be later replaced by geometry in 3ds max for rendering. After some tests, we managed to do it using an HDA called PRTRop which exports particles in .prt file format. The particles were then imported into 3ds max using TyFlow, that reads a couple attributes such as width (pscale), id - this one is necessary for tyflow to import the particles, velocity, etc... Then we hit another roadblock: what if I want to export particles with orientation information for my geometry instancing? It turns out that, after some more testing, we discovered Tyflow uses an attribute called Orientation (case sensitive) which is a quaternion just like Houdinis orient attribute, and it has to be exported as a float16. So in case some of you were wondering how to do this, I'm sharing the workflow used here. If some of you know a better way feel free to share it... it might save some lives! Cheers, Mozzo
  21. Lets say you use c4d and you instance an object into different particles (with random rotations for example). If then you export that instanced geometry as an alembic and import it in 3ds max you get geometry with world transformation information (each geometry instanced has its own rotate/scale/translate info). Is it possible to do the same in Houdini?
  22. Emit pyro outwards (not upwards)

    Hey everyone, I have an animated object moving in a sin wave type motion. I am trying to emit smoke outwards from it. At the moment the smoke is just rising in Y which isn't what I want. Any suggestions? + i made an awful unnecessary diagram, it might help or it might be confuse matters
  23. Hi, I have some particles stick on an animated object, wherever it goes the particles keep their position. Now, what I need is these particles to "walk" on the surface of this object like they were insects. How can I achieve this effect? Thanks!
  24. kill by velocity

    Hey guys! I need to kill particles that have little/no movement. The trouble with killing by velocity is the particles that are moving, are varying in the axis they're moving in so I can't just kill @P.y ? Any suggestions? Is it maybe possible to get each a particles speed of some sort?
  25. Hi guys, I would like to know if there a better way to do this kind of powder stuff with a lot of detail (like the picture) than grain simulation because it's really heavy.. Thank you.
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