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Found 74 results

  1. Vellum grains problem

    Hello friends, I just try to build up a little rbd-vellum grain scene where some geo is interacting with the grains. So far so good. The meshes interact with each other and the solver works. BUT I have no clue why the grains start collapsing in the first frames when starting the simulation. It seems that there is a particle separtaion between the grains that is presolved first or before everything else happens. Does anyone know a solution how to fix this issue or give the grains a "sleeping state" before it collides with the geo? I already tried the popawaken after the vellumsource but with no effect. Thanks in advice, Sebastian vellum_grains.mp4
  2. Wire solver from moving lines

    Hi, I'm trying to figure out a saliva effect and am currently looking at the strands of saliva connecting the top and bottom of the gums and mouth of the creature tgats been animated and brough originally as an alembic (now cached to houdini geo) I've got points scattered correctly on deforming geomettry, then used point deform and add to connect the points, and have been following the entagma connect the yarns tutorial to resample the lines and set the mass for the connecting points to 0. However when I try to go to the next step using a POP network I can't figure out how to have the POP source update the lines and am only able to simulate movement if I create them on the first frame. Is there a mrelatively simple way I can get these lines and their anchor points into a DOP or POP network so I can simulate them to add some movement? I'm looking to mesh them and add then to some drool that im trying to put together using the condensation shelf tool. Any help is greatly appreciated EDIT: figured out the simulation using vellum thanks to Rohan Dalvi, although if anyone could give advice on how to mesh these look close to the strands in this video that would be amazing:
  3. Grains and RBD mutual interaction issues

    Hi there I am trying to get rigid bodies and grains to mutually interact however the grains seem to invoke a disproportionally large amount of force onto the rbd object causing it to fly off into the distance It works fine using one way interaction but not two way. Please could someone more experienced in the matter help me Thanks a bunch For some reason this jammy dude's scene works fine (I'm assuming his is two way as that seems to be the shelf tool default) grainsWeirdness.hipnc
  4. 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
  5. Modelling Zen Stone Garden

    Hi there, I am a new user trying to get into the modelling side of Houdini after trying some simulation, and am currently working on a japanese stone/zen garden based on this image. I've found some great examples on how to create the stones (not worried about moss yet), but I was wondering if anyone out there had any idea how to create the combed patterns around the stones. I just finished doing some work with the ripple solver, but thats too realistic in this case. Ideally it would be something more simple involving grains or particles with instanced geomettry building up more based on a simple black and white image that i'd make in illustrator. Apologies if this is too simple a question, any help is very much appreciated. Thanks, H
  6. Hello, I'm trying to create an effect very similar to the one in the reference video, where particles move through this channel and creep over this bubble. I tried different approaches like vellum grains, regular particles and came closest with the lava shelf tool. But then the individual particles are not touching the surface of the bubble and the overall movement of the particles looks too much like a fluid. I actually want the distance between the particles to stay constant. I think some PBD approach would work best, but can't quite figure it out. Any ideas? Thanks in advance. J NanoParticleEffect.mp4 190524_NanoParticles.hiplc
  7. Hi There, I am trying to set up a initial state for a grains sim(that has constraints). I saw those two tutorials about people having similar problem: https://lesterbanks.com/2018/03/initial-state-houdini-simulations/ [lesterbanks.com] https://forums.odforce.net/topic/21727-set-initial-state/ [forums.odforce.net] It seems like that method works for grains/particles that are with out the constraints though…. Has anyone idea how I can solve that ? Thanks a lot for help! Grains_Initial_State_Test_v01.hiplc
  8. Hey, so to preface, I'm a newish c4d user/ total Houdini newb. I created a grain simulation in Houdini and exported it as an alembic, then brought it into c4d. When I imported it to C4d I imported the grains as polygon objects, and it looks fine in the viewport, but when I try to render nothing appears. The way it appears in the viewport The way it appears in render, with a hair material and render apply I did some googling and tried applying a hair material tag and render tag to the alembic particles, and now the material shows up in the render material but it looks nothing like the way it appears in Houdini or in the viewport. I also tried importing the alembic as particle geometry, then using thinking particles to assign geometry to the alembic, but my c4d crashes every time I try to render it. Anyone ever run into this issue before? Thanks!
  9. Hello! I have recently been offered my FIRST FX job! I am familiar with Maya, and some Max, but this job requires that i use Houdini, so now i am all in! VERY EXCITED!!! I have a scene where i have to make some letters rise from sand. The issue is that i cannot get things to collide correctly. Doing my research i have tried using it as a RBD object, and using a trail sop to computer its velocity, but i still dont see any collisions. I use static object, pointing to a VDB smooth as the proxy geo, and all of the collision detection/mode set to volume, but no collisions still. I set the sim up with an initial state file too. Could that be the issue? When i take away the VDB to polygons and VDB smooth, delete and just run the sim as a regular static object, everything works! But...i get some weird artifacts rendering. What is the best approach to this method in Houdini? Im sure the solution is just a setting away, but im lost here. Any suggestions? LetterSetup_001_collProbs.hip
  10. Keyframed Grains

    Hello! I'm a new user of Houdini and I'm trying to do a stuff like this (https://gfycat.com/aptdishonestcow), using a fbx animated character. Im using grains (granular solid) to do the simulation, but i don't know how to start the simulation only at the desired point (The character start running and falls on the ground. I want to enable just when he falls) Someone can help me to do this step by step?
  11. Fur and snow (+hip)

    Hi everyone! The past week I worked on a personal project for learn something about hairs - vellum. It's my first project ever with hairs so I guess is nothing special but several people asked to see the hip file so here it is. Final result: Hip file (I had to recreate it but it should be pretty much the same): groom_clumping_03.hipnc https://andreasbabo93.wixsite.com/sbabovfx/example-files (new version, there was an error on the other one)
  12. Starcraft Growth Project

    Hey there! Trying to be more active. Here's a WIP of a project I did for Peter Claes's Houdini class. Such a cool technique to play around with. Struggled a ton, and have lot of extra RnD elements that got gutted haha. But I learned a lot. Have to Re-Render, have some slime / rivulets for the eggs in the next render, which I have been struggling with. Initially was flip but switched to something simpler and less heavy.. Had issues transferring V for motion blur due to changing pt numbers but I'm sure someone probably could figure it out! Wanted to add one of the eggs exploding. but stretched thin on time. Will do another rnd for it. Will re-render without motion blur I think. Someone had idea of adding veins, like a neural network that activate and reveal. but I failed at that for texturing lol. I think I could brute force it with geometry to replicate it but that just seems wrong. Also I keep running into Lights inside Volumes on my projects.. makes clearing up noise pretty miserable! Will return to this project after school and expand on it.
  13. Hello guys, I'm struggling with making a basic setup with object emerging from the sand with vellum grains. Has anybody done something like this, do I need to use constraints or just pop awake? I'm sharing my basic scene Thanks! grains_test.hipnc
  14. Hi There! quick question about vellum grains. Is there a chance to stick a part of the grain object to the collider? thanks, Balazs grain.hipnc
  15. How to Transfer UVs to Vellum Grains

    Hey, has anyone tried this yet? In the past when creating FLIPs I would normally carry UVs through DOPs using an attribute promote to carry the UVs from vertices to points, but it seems like this is not working when applying the same methodology with vellum? Please help!
  16. Granis collision help

    Started trying to make a Hour Glass effect but when i press play the grains appear on the outside of the geo, not sure what the problem is any ideas? HourglassSim.hipnc
  17. Hourglass Effect Help

    I'm wondering what would be the best way of approaching an hourglass effect where the sand goes upwards. The hourglass has to be taken out of Houdini and into Maya and is going to be placed into a scene ontop of a table. Any help with how you would tackle this kind of effect.
  18. Hello, is there any analogue of grains attribute "attractionweight" when using vellum solver? Or maybe some advice to achieve the same result?
  19. Vellum Grains problem

    Hey everyone I have a little problem with vellum I could use some help with. I need have a part of the "subject" bloat up and increase in volume to the point where it pops and liquids come out. Trouble is, I cant really get this to behave properly. Most of the time it will stretch the geo too far and not actually tear, even when the break tolerance is like .01. I don't know if I'm doing something wrong with grains or what but they seem finnicky. Also, is there a way to have an active area for the sim to run, like how in an rbd sim you can isolate out an area? I'm using a really hacky way of separating the active and non-active area with which I'm not too happy with.I'm still relatively new to houdini so I feel like I'm missing something obvious. For reference of the effect I'm going for, look up Thunder from Big trouble in little china. Bloat_building_v020.hiplc
  20. Is it possible to create two way collision between rigid body and grains? I am trying to make a simple example where a sphere is dropped down in a container of grains.
  21. Ground / Terrain Collapse Effect

    Hello all, I am looking at this amazing fx made by Axis for Halo e3 2013. Studying the reference ( the terrain fx ), I thought to approach this using RBD fracture to drive a second sim layer of pop grains (sand). However, I am also thinking maybe I could use vdb+volume vops to mimic the motion. and for the second layer, perhaps using just particles emitting in focus areas. I would appreciate your thoughts on how to approach this. GroundCollapse_Reference.mp4 @MENOZ would love your input if possible.
  22. Resampling Stretched Grain Chain

    Hey Everyone, I've a got a scene where I need to stretch out and resample a cable made out of POP Grains. I've managed to get the stretching part going, but the resampling is causing issues. As you can see when the cable gets stretched the stretched parts essentially becomes really low res, so I need to resample it to keep the deformations smooth. As you may have guessed, a resample node inside a SOP Solver did not work. I tried a few different things, including transferring attributes from the old (lowres) cable to the newly resampled one based on uv's, copying some VEX code from inside the POP Grains node itself into a Point Wrangle to generate the needed attributes, and deleting all attributes/groups, recreating the targetP/weight/stiffness attributes and groups, and then letting the solver take care of the rest. None of these really worked. Does anyone have any suggestions for how to do this? I have included my scene file with and alembic file so you guys have a look if you want. Its not the most elegant or pretty thing (still very much in the early stages) but if you follow the bright red nodes you will get to the SOP Solver where I want to do the resampling. Grain_Resample_Help.hipnc shot_0120_maya_export_v004.abc
  23. POP Grains - Experiments and Issues!

    Hello, I have been experimenting with Grains node and shelf setups as as custom setups. I started with a sphere, then a sand castle and last was a statue. Some results were pleasant then I ran into some issues. Weird and strange behaviors such as floating sand clumps. Mainly it looks like too much force or friction. The problem that the solver feels like it is too sensitive (minor values can change things very quickly). Any pointers or advice is greatly appreciated. Copy_of_SandCastle.mp4 SandCastle_002.mov SandCastle_003.mp4 SandSolver_issue.mp4
  24. Agent interacting with Pop Grains

    Hello everyone, First time poster. Coming from a C4d / Realflow background. I have been able to accomplish what I am trying to do with regular objects as a sphere or a cube lets say. I downloaded a zombie crawl from https://www.mixamo.com/#/?page=1&query=zombie . I imported the fbx into an agent and added an unpack node under the agent as I read this was the only way to be able to get it to react with RBD / Fluids etc. My scene consists of a cube with a transform on it to make it a rectangle which I applied a wet sand preset. The rectangle is above the imported fbx zombie. I have a ground plane. I tried making the zombie a RBD and I also tried making it a deforming object. The goal is to sim to grains with the zombie in place (I removed the $T animation channel). Once the grains seemed to be settled and looking like a nice pile of dirt, I spit out an initial_state.sim file. I added the to my dop network. I then selected the zombie and clicked on Awaken by Geometry. I also turned on Enable auto sleep and Start asleep on the pop solver. I am having several issues. I would like once I have my initial state, for all the particles to be frozen or "asleep" unless the zombie interacts with them. Also I was to be able to control the velocity of how his movements affect the particles collisions... and those particles would in turn AWAKEN more particles etc. I can not get any of those to work. I searched every post on the forum with grains. I learned a few things from Rohan Dalvi's tuts. So I am kinda stuck and hoping someone could help me out. I have attached the latest iteration of where I am currently (stuck). Let me know if you have any questions on my end. I just recently bought indie and redshift and loving it so far. Still wrapping my head around attribute wranglers and vex, but one day at a time. Thanks guys! William grains_zombie_crawl_006.zip
  25. hey chaps i'm trying to create a sim of some chips. I want a big heap of them to fall on top of a burger sim i've done! I've tried a few routes and just wondering what is the best way to go about this. I've attached a scene - its a basic setup of some chips model. I've made them packed and they fall. however they are rock solid and just clearly dont have an air of bendyness to them. what is the best way to go about this? I tried FEM ....making one chip... solid embed... multiple copies then run that. It seems to work in a fashion but soon as i turn up the amount of chips it becomes quite sluggish and also if some interpenetrate then you get wildly exploding meshes. I tried a wire solver but found the wires just seemed to do their own thing and not hold a shape or length. I have got the rbd packed working but of course its just simple shapes and they dont bend. I wondered if it might be possible to create a chip that comprises of maybe 5 simple boxes connected together with constraints? attached a scene file below - theres a fem setup in there and rbd packed.. chips_sim_v003_rbd_for_odforce.hip