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Found 154 results

  1. Hi everyone, it's as the title says. I'm trying to create a basic setup where I have 2 fluids interacting with one another in the same flip sim, then I'd like to separate these pop streams to mesh each separately. I've included my working file. Any help would be greatly appreciated! SeparatePOPStreams.hiplc
  2. How do you combine 2 velocity fields?

    So, I am trying to advect some particles around a torus with a 'volume velocity from surface', thing is, once they get out of range of the torus they just kinda stay there. So I am trying to add another velocity field to push them back, however I have gotten awfully stuck on this. In the example I have a torus with velocity and a box with all velocities pointing inwards, so how do I best combine these two? Also Happy New Year to all! vel_test-01.hiplc
  3. Rocket launch pyro test

    First post here for feedback and direction, this mostly a test render for my first big pyro simulation. It's being driven by a pop system that's firing particles downwards and using that to drive a pyro simulation. The collisions for the simulation are pretty broken, please ignore those. One thing that I'm having trouble with is getting the outside plumes of smokes to rise higher, anyone got suggestions? Sequence_1_v01_-_converted_with_Clipchamp.mp4
  4. Hi folks, I'm stuck on a issue. I have a deformed geo that i have fractured in packed pieces. Then I want to use a popnetwork to drive my packed pieces. I would like to update the position and the rotation of my particles with the deformed geometry, but when i try to update the position with a pop wrangle like: @P = point(1, "P", @ptnum) with my geo source on the second input of the popnet, the orientation dosent fit of the original geo, the orientation is not updated. So, how can i update properly (position and orientation) of my packed pieces with the source deformed geo in the popnetwork frame by frame ? here is some video to show you, ths ! What i have, orient not updated: orient.mp4 What i would like, fine deformation: orientok.mp4
  5. Hi guys, I would love to recreate these 2 effects from Michael Rigley I would love to know how to make the one below first. it looks simple and bautiful. https://player.vimeo.com/video/301087373?app_id=122963&wmode=opaque&autoplay=1 and so far I created this .Hip pelotitas.v01.hip Any idea, tip, tutorial, help with this subject comes in handy Thanks a lot
  6. Hi! I am trying to do simulation using crowd system. Agents should decide wich 1 of 3 splines to choose depends on smallest popgroup number in destination point. Could anybody help with VEX in popwrangle? Hier is a scheme attached. I think to use splines because houdini has not navmesh like unreal engine has. And navmesh as far I know just splits polygones and draw optimal spline on its chunks in direction of movement. This should simulate 3 lines in a shop. Agents should go where is not to much people waiting
  7. Dust effects

    Hello, I'm trying to make dust effects like Avengers. I used color attribute by boolean and use pop with it. I'm struggling with generating pop and there is some lagging like the video I upload. How could I fit it and makes it looks right way of emitting particle as well? untitled.mov dust_effects.hiplc
  8. I am doing a small rain system. When i add the trail sop, followed by an add to connect the point with the ID attribute, everything works fine until i set the trail increment to a value different than 1, then it completely breaks. I believe it is because particle are dying, but i cannot figure out how to debug it Trail_sop_issue.hip
  9. Fluid into FLIPtank + interact

    What I am trying to do is to get a fluid of any kind (pop or flip presumably) to interact with the fluid in a flat fliptank. Seems like it should be easy, but I can't seem to get them to react and mix like fluids (or interact at all actually). More detail: I actually am trying to get a cloud of blood to spread out into a pool under a body that has just fallen in. Perhaps this means I need a different solution than if I was dumping particles into the tank from an emitter outside of it, but I can't even get that to interact, so any advice on this would be most helpful, and I am grateful to anyone who spares even a moment to consider the problem. Much appreciated! PS- I have scoured the internet, including this site, for advice on this, and have come up empty handed.
  10. CONFETTI PARTICLE FORCE

    how can i create this effect in houdini. basically i need to know "how to make this particle sim" if possible please make a file for me. Effect is video reference in this link: 11 sec . https://vimeo.com/172598946
  11. DOP to POP

    Hi guys! Just looking for a little bit of help, to see if what I am trying to achieve is actually possible and if it is maybe someone could assist me in figuring it out! I have attached my file below, I am attempting to make a Volcano react. This is the reference I am trying to copy to the best of my limited abilities! https://www.youtube.com/watch?v=9Plj4b79cwg My question is in regards to the node named SIMULATION, ignore the first DOP for the first smoke. I am working on the out put from the lava, now everything looks horrible, but I am trying to get the set up to work so I can edit things all at the same time (Uni assignment, short time frame, was recommended to do it this way.) Anyways I have the 'Lava' moving kind of how I would like for now and I now want to take the movement of the lava and turn it into particles to put into a POP to create small particles/sparks. I am certain this could be done. But I cannot wrap my head around how to achieve it, I got it done for the secondary smoke from the lava plugging the output into a pyro, which I haven't edited yet so that reaction is a bit of a mess. But I want to figure this out before moving on! Any help or recommendations would be hugely helpful! Or even if you know of any tutorials that walk through this? As I haven't come across any.... Thanks! Assign07e2.hipnc
  12. Hi guys! I have a problem that's been bothering me for a couple of days and I can't seem to wrap my head around to solve: I have a grid, with scattered points. And I have 3 objects hovering above the grid. With a colour shift on the grid (attribute transfer with an animated ball for now), I "activate" the points in a pop network, and I start adding forces on them, choreographing them, until they reach a certain age and start to move to the 3 objects above, like an attraction (point count is the same in both inputs for simplicity - also I have colour grouped which particles belong to which object for visualisation purposes). So far so good. The problem is that in theory, each $id should correspond in each point on the objects above - but alas, they seem to shift groups! So, instead of clean motion / attraction on each of the objects after a specific time, I get more of a random mass of particles moving back and forth the objects until the end where they stick on the objects. There sure is something wrong with my vex, but I cannot understand what! It should be easy: green goes to green, blue to blue and red to red.. Attached are some images to help understand the problem. the viewport describing the problem: the pop hierarchy: the wrangle to move the points to position after a certain amount of time in the "time_in_release": If anybody has any idea as to why this is happening, please, feel free to share! I would be more than grateful to hear your thoughts! Thank you so much for your time, G.
  13. growing line effects

    Hello, everyone. I'm trying to make the growing line apart from object and I have few problem. So far, I made growing line from object and i would like it to move away from the center which means that the center of pop generation is too high density. However, I keep the speed as slow and I just want wires (I generated it by pop and use vdb so, looks like wire growing) go away from center slowly, so looks center less density. Sorry, my explanation is too bad since I'm not native speaker, but hopefully you guys understand what I said by file I attached. And, if you know good way the wire looks sharp, please help me. Thank you. grow_wire.zip
  14. Packed RBD from Pop Sim

    Happy Friday, Trying to wrap my head around constraining or copying packed rbd's to particles that are moving along a surface. Attached is my test scene please help if you have time! Thanks, particleRbdTest_01.hip
  15. Flip Sphere Motions

    Hey there, I'm trying to replicate this setup: Liquid Sphere Based on my scene, I have a sphere and the particles are generated from it with iso offset and particles from volume. Within FLIP, I tried to control the velocity with pop forces (POP force, pop attractor and pop axis force) and got somewhat of a swirly motion but the in the reference video, towards the end you can see the fluid is ground around a torus like motion and the shape as well Any pointers on achieving this? HIP file attached included. Thanks! SH02_Water_v02.hip
  16. Hello everyone, I've seen multiple posts and some discussion on regards to sprites, but most of it is from 8 or 10 years ago, so I was wondering if anyone would have some insight on a workflow or an example on H.17 for adding a looping image sequences to sprites. You must be thinking, "sprites? people still use those?", but the style I'm aiming to achieve relies heavily on some 2D animation. I've used some techniques with traced 2D sequences instanced into particles but for the sprites I am a little lost, specially when it comes to rendering the sequences. I've created an attribute for it based on the life $HIP/Sprite_v001_`padzero(4,round(fit01($LIFE,1,20)))`.png but not sure where to use it afterwards (shops have changed a lot in recent years). Also tried adding something to the Sprite Map on the popsprite inside dop: $HIP/Sprite_v001_`padzero(4,$F%40+1)`.png but still no success. Any help would be greatly appreciated.
  17. Hi, I'm a beginner in Houdini learning alone with tutorials, I need some insights about POP. What I'm trying to achieve: I want to reproduce this effect, but slower: Basicaly, I have a polyline forming a shape, I scale each primitive in a foreach loop with x iterations. Each iteration go through a DOP Network with a different seed based on the index of the polyline in the for loop. The DOP Network move points with a curlNoise, I then create a trail. The screenshot shows the effect on a single instance. Questions: 1/ I can't access the Birth Parameters on the POP Source node. From the help, it seems "Impulse Activation" at anything but 0 to be able to access those settings, but it's greyed out. Am I missing something? (It's greyed out even if I input "1" and not an expression.) 2/ To get a lower number of points, I used an Impute Activation of (($F%20)-1)*-1 == 1 point every 20 frames. The problem is that now, the DOP network does not begin before $F=20. Is there any other way to tell POP not to birth points every frames while being able to choose the first birth frame? 3/ I want each point created in DOP to keep as an attribute his original position (when his age was 0), and I want each new point to keep @ptnum of the source point as an attribute. How can I do that in DOP? Thanks!
  18. Hey Everyone! Is it possible to define a region (perhaps with a shape) which pop forces are applied. I have an rbd sim and am looking to have a specific area that is affected by a pop force. Any ideas? Thanks
  19. Particles will bounce off a collision object, and I can influence that using the collider's Bounce parameter. Great. However, if I change my particles to grains, they will not bounce anymore, but slide. No matter what I do and this goes for pop grains as well as for Vellum grains. Settting ispbd to 0 is not a real solution, as this means I am not using PBD/Grains, anymore. Any idea? Here's a very simple test scene, using a pighead. Just activate/deactivate the POP Grains node in DOPs. collision_grains.hipnc
  20. kill pop force contribution on Y

    hey! is there a way of limiting or killing the contribution of pop force in an axis?
  21. Hi, In my popnet, I want that, a new particle is born only if there are no particles in the scene. That is, suppose a single particle is born and dies after, say some random frame, only then a new particle is born. No new particle can be born even if a single particle is alive. How can I do that? Please help Thanks @Alain2131 : Sorry to tag you here, I just wanted some more help. Please let me know if tagging is not permitted or if you are bothered by it, I wont tag you again.
  22. Hello, I have an object what I broke with an rbdmaterial fracture then I feed the points into a popnet and add some stuff like wind to move the points. My question is: How can I reset or rebuild or move back the points into their original place and shape like a fast rewind or something. Thank you
  23. Underwater Bubble Sim

    Hey guys, so basically I'm trying to replicate an object dropping into a tank of water splash but with the bubbles/water only. The way I'm currently doing it is by emitting particles based on emission attributes defined on the surface based on it's velocity and using vdb from particles to mesh the liquid and so far it's alright. However, the client wanted a more art directable look towards the pop sim whereby more lengthy/streaky bubbles instead of huge splash etc and it got me thinking how can I achieve this? I'm on H16 and there's no pop fluid where I can easy increase the surface tension and viscosity to save my shot. Is there any pointers on hacking this shot without doing Flip? I'll upload my WIP, files and other references from client tomorrow. Thanks
  24. Duplicate objects in RBD pop net

    DOP net question. I want to start with a set number of boxes and have them move around with POP forces and bounce off each other with RBD. Problem is that I end up with two items for each one I put in. For the POP source I setup Impulse activation to be $F == 2. If I use 1 there, I only get one set of items but they aren't effected by the POPAdvect forces. Feels like a rookie mistaken, but I not sure how to set it up. Any ideas? POP Source: Emission Type is All Geo, Geo Source is First Con text RBD Vector Field.hipnc
  25. hey everyone, I'm struggling with a problem. Here, the particles move randomly. I would like them to become visible when they pass through the cone until it comes out. I don't know how to proceed, I tried a few things but couldn't get something to work. How should I create the collision attribute and apply it to my attribute vop ? Could someone help me or guide me a bit, please. Thanks particule_collide_dust.hipnc
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