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Found 48 results

  1. Hey everyone, Been trying to wrap my head around this one for a while but after a few days of being completely stuck it would be amazing to get some help with this point deform problem I'm having. I've got a pretty simple set-up that's using the grain solver for quick softbody deformation, I've got three primitives scattered onto some geo which is then being fed into a dop net for simulations, That part is working well, the only issue I have is when I want to re-attach the original mesh to these objects with a point deform, I've been trying to create a for-each connected primitives for my point deform so the deformed recognises each piece as its own object however i'm getting some strange deformations on my objects when I try to point deform them. Any Ideas?
  2. Hello! I'm using grains to fake cloth and I'm having this weird issue where I'm using a popwrangle to update my targetP (because the constraint points are animated), and it seems to be dragging the target points towards the origin? I've compared my set up to a couple example files and can't quite figure out what's gone wrong. Any help would be appreciated! Example file attached targetPointIssue.hiplc
  3. Hello everyone! I'm just wondering if someone knows how to create that a Particles meets and other particle stick togheter, and if is possible to made that. If there is a particle floating around and get close to an other particle floating around can they stick togheter. or any way that I can aproach that?
  4. Particles

    Hello everyone! I'm just wondering if someone knows how to create that a Particles meets and other particle stick togheter, and if is possible to made that. If there is a particle floating around and get close to an other particle floating around can they stick togheter. or any way that I can aproach that?
  5. I adjust the 'Clumping Weight' which I believe is the 'attraction weight'. However when I look into the geometry spreadsheet nothing is updated in the 'attractionweight' after I adjust it. In my still image I created an attribute called 'attractionweightB' where I added it to the 'Weight'. Yet nothing is updated. You can see a comparison where there is many different values in the attraction weightB seen in the geometry spreed sheet, yet the original attraction weight stays at 1. But even if I were to set it to '0.6' for example. I still don't see that value in the Geometry spreadsheet. Please help.
  6. bacon Grains

    would anyone happen to have the bacon scene for that is shown in the master class at time 41? I want to learn how to emit from pops some geo and still be able to use the point deform,
  7. Hey friends, I'm pretty new to Houdini but I'll try to ask you my question in a hopefully understandable way. Can anyone tell me if my workflow is right or if I go the totally wrong way with my thoughts by challenging the task of placing different objects on a surface. I want to achieve something like macro-shots of a beach/sand. Means I want to model different assets and scatter them on a surface with different rotations and scales. They also should not interact with eachother by obtaining a certain distance to each other. Things I have done so far: - procedually modelled 6 grain-assets (lowpoly, about 3k polys each) - grid displaced in Y-axis with mountain - scattered points on the surface My thought is to scatter 6 different seeds of points to the surface and give them different values of Cd and pscale. After this process I want to merge the points into one "point-container" and scatter instances of the lowpoly meshes at the diferrent color-locations. I heard something about the copy-stamp operations but I also heard that this is way more inefficent by using computer-performance than other solution. As far as I know Houdini offers pretty solid graintools. Is there any way to hook up my own grain-assets in this shelf-tools? I tried it for some while now and didn't achieved a solid workflow. Is it possible to make something like a thin layer of sand on a surface without interacting geometry, because I don't need them to be animated in the full space yet. Thanks, Sebastian
  8. POP Grains Collision Issue

    Hey there, I'm having an issue with my POP grains sim. I'm trying to simulate spaghetti or noodles on a plate which are thrown up into the air as the plate is flipped. I was able to modify a scene file to create the noodles and create collision geometry based off an alembic file I was provided. However I'm having two issues: 1. My grains don't stick to the plate the entire time, some of them go through my collision geo 2. I'm getting some very weird stretching with the grains as the sim progresses. I'm not sure if there is some other collision elements that I am missing or settings on the grain nodes that I need to tweak. I've attached a flip and hip file. Any advice would be greatly appreciated. Thanks! noodles_v01.mp4 noodles_v04.zip
  9. Hey all, I'm banging my head against my desk trying to figure this out....I'm attempting at creating a spaghetti-like simulation where noodles start out on a plate, and then the plate is flipped and throws the spaghetti off the plate. I'm generating some noodle-esque lines using pops and grains but I cannot for the life of me figure out how to get them to not intersect. Am I missing something? I was also hoping to add meatballs to this at some point as well which would be sitting on top of the noodles and then get thrown off the plate as well....would this be accomplished with adding a multi solver to my pop network that combines the popsolver with a bulletsolver? I've heard grains and RBD objects don't play super well together so I'm not sure which is the best approach for something of that nature. Thanks for your time!spaghetti_RD.hipspaghetti_RD.hip
  10. Constraint RBD to Cloth (or Grains)

    Hello guys, How can I attach a rigid body object to a piece of cloth? I'm a bit lost on this. I tried cloth and also pbd with no success, now I have no idea on what i should try. There's a file attached (using grains). It's a starting point if anyone can give it a try. Cheers - Alvaro rbd.to.grains.v1a.hiplc
  11. Granular Sheet - Moving Pin Constraints

    Hey everyone, after unsuccessfully scouring the web and the two big Houdini forums I finally brought myself to asking directly. I'm currently trying to animate a sheet of cloth using a granular sheet since the FEM approach is just excruciatingly slow. I've found three methods for pinning parts of the granular sheet in position (@stuck, @mass = 0, @targetP) but I wasn't able to find a use either of these methods for an animated pin constraint. I'm obviously still not really proficient in Houdini since this problem has me completely stumped. So if any of you lovely people would point me in the right direction, I'd be immensely grateful. Thanks in advance! *edit: After searching some more, I came across this thread: While the file attached to the thread works when I play it, when I try to copy that setup into my scene, it just refuses to work, even though the @targetP gets updated. Obviously, I'm doing something wrong but even comparing the node settings side by side I can't for the life of me figure out what that something is. *edit #2: Okay, I finally figured it out. I didn't realize that the sop solver node is empty by default and you have to create the sop structure to update every frame by yourself. Now that I've figured that out it is perfectly reasonable, I just didn't think of that for quite some time. dia3_dmo_001_010_cgfx_setup_v003_pj_stripped.hip
  12. Field-O-Spheres

    This is the first thing I've done that I'm legitimately proud of. Simple, but a lot of fun! Took inspiration from Brandon Woelfel and a lot of the scenes in Pop's Dinner in Riverdale. Any feedback would be great
  13. Freezing Attributes

    Hi Odforce! Im working on a little project using the object packing technique from Ben Watts Design's tutorial. I've got an attribute VOP using turbulent noise to drive the pscale attribute. Im then reading this into a popnet through a sop solver, but when the particles move they adopt the pscale of the underlying position of the noise. I believe this issue is related to the sop solver reading the new pscale in every frame but im unsure how to essentially freeze this attribute. I want the points to be born, adopt the pscale based on the location it spawns on, then for the pscale attribute to remain frozen for the rest of the simulation, how do i go about setting this up? I have attached the scene file here. CardGrowth.hip
  14. Grains cloth - bend resistance

    Using grains for cloth is extremely fast but since it’s not a fully fledged cloth solver it lacks control for creating realistic cloth sims. There is only really self collision and a basic stretch resistance through explicit constraints (through to avoid stretch you have to put constraint iterations very high..), but it doesn’t seem like there’s any concept of bend resistance in the explicit constraints. Does anyone know of a way of creating bend resistance or faking it somehow?
  15. Sand Simulation

    Hi! I'm a student at NAD in Montreal and I'm trying to learn Houdini. I have a project in which I need to simulate sand on top of a falling rocks RBD simulation, which is on top of a FEM sim. (The FEM is the deforming ground) So I cached every collision objects with the CollisionSource node (with 4 substeps to match de grain solver). Now, if I simulate the sand, it explode on random frames. (see flipbook here: password: sandsim This is my second attempt and it still explode (at fist I used 10 substeps) Does somebody have any ideas on what could be the issue? Thanks MountainGrowth_47.hipnc
  16. Hey magicians, Been fighting with this pile setup for a couple of days, I need to make a candy pile, I'm using grains but when I replace the geo there are some artifacts like the geo is inside the particle and leaves weird holes, anyone knows how this can be fixed? It need to be the more realistic way possible @f1480187 would love to hear your thoughts sensei Thanks pile3.hip
  17. Grains - Disable Constraint Averaging

    I posted this on the SideFX forum but haven't had any response so I thought i'd try my luck here: I'm getting some unbalanced forces when using grains, its the same problem as described in the grains masterclass around 32:50. As Jeff says the solution is to disable constraint averaging and then insure all the internal forces add up to 1. I've done this but I still have an imbalance.. I wanted to check which forces are meant to add up to 1, in the video it implies that Internal Collisions + Clumping + Explicit Constraints = 1. However in the help document it mentions that Friction with Particles should be included as well. So should I set Friction with Particles, Internal Collisions, Clumping and Explicit Constraints to 0.25? (
  18. I'm having a play with grains for making simple ropes and cables, and the problem I'm having is that they just bounce and stretch waaaaaaaaay to much! The rest length attribute on each prim is the exact length of those prims (and therefore the sum of all the rest lengths is the length of the rope) and the substeps on the pop solver are set to 10. What I want to do is simply reduce the amount that the rope stretches and bounces. Up till now, the only real solution I've found (and seen other people do), is mess around with forces and substeps (in one case I turned them up to 1000), but doing it that way just feels so convoluted and still doesn't let me tune in the exact results that I want. I've also been playing around with attributes as well as having a dig around in the solver itself to see if there is anyway to modify it, but alas I have come up with nothing (I'm struggling to figure out whats going on the grains node). I guess what I'm wanting to do is find a way to control how the rope moves/looks (ie the stretching and bounciness) with physical properties instead of forces. In other words, instead of having to use a pop drags and all that, just get the rope to not be so susceptible to stretching in the first place. Does anyone have any ideas?
  19. Rigid Object using Grains (styrofoam)

    hey guys, is there a way to make a granular solid to be very rigid? Not cloth like. I have to simulate a detailed styrofoam breaking and it would be perfect if I could work with grains. Thx, Alvaro
  20. Partial collision detection

    hey, little problem here. I have a piece of cloth made out of grains. Its colliding with an object. Here I use a collision detection in combination with a collision behaviour. The collision detection shall only detect a few polygons of the whole object to stop the motion there. Referencint the polys in dops. Its giving me a correct collision guide but during the sim it keeps ignoring it. Insteat it freezes the grains along the whole 'main collision object'. So that are the areas to collide with, just a few squares.
  21. hey guys so this one is thumping my head i have a popnet with some grains... its working well. now i want to simply cache out this simulation to disk, then bring it to another hou file. But what is the best way to go about that? I'm just lost here. i can cache it out a .bgeo sequence and then fetch it in with file read node into a blank hou scene but the grains have lost their spherical look and the ramp colour too ? I cant for the life of me suss out how to plug this into a new popnet scene anyone with any advice much appreciated losing my head here ant
  22. I've found that with finite elements(or cloth or wire) you can create multiple iteration of an geometry in a sim with the Creation Frame parameter. using floor($F/10)*10+1 see attachment I'm wondering if there is a way to do this with grain solids. I can add multiple pop source at the beginning of the sim but i would like to create a new Pop solid every 10 frames the way I can with FEM. I tried animating the impulse activate on the pop source and tried changing the activation parameter on the pop grains node. I'm guessing this is not really possible without multiple pop source nodes and point deform nodes. But maybe someone here has a solution. thanks
  23. Grains morph target geometry

    Hey, how would you go about transporming the target geo in something different without having the grain solver go crazy? So not just a transform, shuld be a different kind of geo. Also with intact constraints.
  24. hey chaps so pretty simple one... made a ball, applied granular solid from the shelf. now i have a simple knife tool that drops on it cleaving it in two. really quick... takes mins to setup in houdini - love it. So heres my questions... i have the embedded mesh but when it slices its still one shape - how can i slice it into two? (the other thing i have is the grains which i converted into vdb then back to polys) for both/either of these results how can i transfer an inner colour into the geo? in my naivety i object merged the knife into my vdb then applied attribute transfer to transfer colour - but the colour wont stick as the two halves drop away from the knife. anyone got any cool ideas? ta ant
  25. two objects in a granular solid sim

    I'm trying to set up two pig heads in a grain sim that collide together. an extension of the grainular solid example in Jeff Lait's h15 grains masterclass. in stead of one pig head i want to wire in two. I've set up two pig heads (skipping the bone group part for now) see attached file. Jeff shows how to override the P and v with from an animated version of the geo with a wragle. I've set the dop net up the same way with two sources. however for some reason one of the P values apparently collapses to 0. if i switch the merge order it switches which source goes to 0. see attached file. I'm obviously missing something here. help would be appreciated. twosolidpigs.hiplc
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