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Found 129 results

  1. Hi there, I'm trying to control flip particle count per voxel. The idea is to evaluate particle count per voxel on every step (Gas Particle Count) and then analyze the pcount field.. If pcount > n - delete some of particles (pcount - n) to make n numbers. And if pcount < n - add (n-pcount) particles. Any help is highly appreciated. Thanks,
  2. SOP GEO - FIELD FORCE - BULLET

    Hey guys, working on a destruction peice and wanting to take the velocity from my charachter and put it into my bullet sim - So decided to try and use a sop geometry node to bring in the calculated velocity (from a trail and fluid source) - which is working perfect. But my sop force doesnt update each frame, its static - ive tried changing the expression from $T to $F and other things, not sure if its a limitation or if im doing something wrong? i will attatch a file but will be missing the geo but atleast you guys can see the setup Any help would be great! Thanks Destruction_v3_t2.hip
  3. I have three individual components to this briefcase, the body, the handle rings and the handle, the body is a static objects and the other two are RBD packed objects, all concave. I am trying to get the handle to hang from the suitcase naturally but they are falling through each other, there is a slight reaction but i cant get them to completely react to each other. I have attached a zip of the three .obj files and the .hip file if anybody could have a look. Any help would be really appreciated ! Thanks! Assets.zip
  4. Zero gravity FLIP Sim

    Basically I have a 'liquid metal sphere' that floats up in zero gravity and starts to peel off using a flip solver and reveals the solid metal sphere underneath as everything peels away with a paint like viscosity. I have it all working EXCEPT for when the FLIP sphere and collider move upwards (because of the animation i want it to look like zero gravity) it leaves a trail behind it kinda like where it starts the sim, ' I want to have it all move upowards and then the gravity starts to peel off the 'paint' from the collider sphere Thanks for any suggestions also attached an example file ZeroG_test.hiplc
  5. I have a load of RBD packed objects smashing on a Ground Plane, they're all intersecting by a consistent distance through the Ground Plane, the RBD packed objects are all convex hull rather than concave although changing between the two doesn't seem to make a difference. I've tried replacing the Ground Plane with a static box and trying different geo representations on it but that doesn't seem to work either. Any suggestions on how to fix this would be really appreciated! Thanks
  6. I have two separate stacks of geo made using copySOP's, i am trying to get them to interact with each other. They do interact with each other but the constrains only effect one model, i can switch them in the merge but its only ever one that holds together, the other falls apart instantly no matter what the glue strength is. Ive put photos below and attached the scene file with the model that needs referencing in. New to Houdini so any help or advise would be greatly appreciated! Thanks PlateSimulationTest001.hipnc plate.obj
  7. I Have stacks of plates and bowls that i made with a copy node on one original model of each type of plate or bowl rather than importing each model multiple times. I want each object to be able to fall and smash independently which i am struggling to work out. When i make the stack a RBD Glued Object it either all moves and smashes the exact same way like they are being read as one whole piece rather than individual plates/bowls or they move individually but the glue errors saying "making objects from different solvers mutual affectors" so they cant smash. Sorry if this is a basic question i am new to Houdini, any help would be greatly appreciated!
  8. i have managed to create a network of masked gravity force to drive the RBD packed objects but I'm a little confused about how to proceed further. i need to control the moving pieces of geometry more effectively with further forces as well as create debris from the cracks or where it fractures. any direct help (i have attached an example file) or pointing me towards resources where i can learn further would be cordially appreciated. thank you and best regards fracture.avi fracturingGeoMaskingForce.hipnc
  9. RBS SIM

    Hi ,i use Houdini apprentice 15.5 for 3 months now and i have a problem with the RBD collision.In fact, i'm doing and exercice and the goal of the exercice is to have realistic mouvement when the tube push and object on the table. But the collision of the RBD Objects with the ground is not realistic. The thing is watch tutorials and i reproduce in an empty scene the tuto and it works fine with a simple object like a table and a cube, i mean when the cube is put onto the table the cube does not pass through the table. But in the scene you see bellow everything was working fine until I apply the glue node onto the bowl. After that the bowl the dinner plate and the waterglas pass through the table and it is the first issue i have.Secondly when the objects fall onto the ground the collision is not realistic.I need some one help to fix this problems.Thanks you
  10. Running a fluid sim over geometry

    Hello! I was wondering if anyone knows a way to run a flip simulation over specific geometry. The closest visual reference I can think of would be the workflow from Moana. Would you have to turn the geometry in to a fluid object, or is there some way to have the simulation run on top of the geometry?
  11. Cloth sim for sails

    Hey guys, I'm struggling with the fem solver. Basically I would like to create a realistic looking cloth sim for the sails of a ship. Unfortunately I just can't get it to look right. The wind force deforms the object like animated noise insteat of adding variable velocity. I fit01ed nearly every parameter on the wind force or uniform force but it keeps looking like jiggly gum, not like cloth floating in the air. Can anyone show me an easy example on how to achieve something like this? https://vimeo.com/136480165 [vimeo.com]this is how my gum looks like: https://vimeo.com/197677800 [vimeo.com]Thanks!
  12. I want to make a scene that bullet pass through glasses(with fracture), fluid sims and other objects. but, when I make sphere to bullet size, It can't pass through and just bounced off. 1. How can I fix it ? 2. and wanna make it slow which node can I use for it ?? sorry for my poor English and will be pleasure if you help me Thx for read.
  13. particles path circle

    Hi guys! I've made a sim with particles but I would like to keep them rotate in circle for some seconds and then use their inherit velocity. how i can keep them rotating? i've been trying to add angular velocity with cos ($T * 180) ty = sin ($T * 180) this expression, but doesnt seem to work. any suggestions? thanks!
  14. Guys anybody know how to use distribute shelf tool if I have custom dopnetwork inside sop ?
  15. FLIP Cache - Best Workflow

    Hey guys, I assume that the best workflow could be: 1st - Write the particles simulation to disk 2nd - Read the simulation files to generate the mesh (+ cache the geo file) Now, what is the best way to save the particles simulation? Should I do it inside the "particle_fluid" node using a "ROP Output Driver" or a "Flie" node? Should it be connected to the "import_particle" node? Something like this: and how should I read those particle files back? Please let me know if there's a better workflow on it. Thank you, Alvaro
  16. I'm posting this on behalf of Benuts, a VFX company based in La Hulpe, Belgium. We are looking for an experienced artist to help on water/ocean simulation and shading. We're looking for someone with a lot of experience on that specific topic to help finalise shots for an ad, with opening sea - Moses type effect. More information will be provided after contact. If you are interested, please e-mail Alexandra Meese : alex@benuts.be
  17. Hello, I'm trying to create a looping animation of water spiling on the ground, so that it repeats itself every 60 frames , but im stuck at the part that where I need to blendshape the last frame and the first frame since I can't find anyway for the points to be blend shaped to their nearest relative point. waterfallloop.hip
  18. Hi all, I've been using the crowd shelf tools this week, trying to get to know them. The example files are super helpful, and have taught me a lot, but I'm getting slightly stuck on one seemingly simple thing. Controlling the initial position of the agents. For example, I have around 10 agents, walking, following a circular path. However I cannot figure out how to define the starting positions of the agents to be along that circle (so that they are all walking around it from F1). I can only seem to be able to randomly populate a surface, or set the population to 'formation', which allows me to do a straight line, but not a curved one. Both of these are v useful, but is there a way to set a custom starting state for agents (i.e placed along a curve)? Basically I want to set up agents walking around a circular pool. Any tips much appreciated. Thanks.
  19. My Latest Houdini works

    Hello Guys Im Ahmed Saady - Houdini FX Artist based in Iraq now i would like to share with you my latest houdini projects i have done and i hope you like them Also i'm available for freelance remotely work or full time position ahmedstudios@gmail.com Copa America Identity 2016 - beinsports Copa America - mainstudio 2016 Building Destruction - R&D All the information regarding of the houdini work is under each video description Thank you!
  20. another pyro question

    Can someone tell me why often in time people will like to separate out density, temp, vel and merge it back in the smoke object in pyro ( under the initial data as: density SOP path, temp SOP path...ect) instead of that, we can put multiple source volume node to input different channel as well. What is the main different here? All I know is putting those SOP path makes it last longer in the sim, thinking like as if you want to have a shape of a box being evaporate then we will use that and if we are using any of the initial data we will most likely not wanting to put down the Source volume node where this is constantly pumping stuff into the sim. In addition, to do any of explosion sim, is the best not to put fuel data as any initial SOP path since those will stay quiet a while if you are sourcing the fuel on your Source Volume already. In render you will have a constant light area where is being burn even your explosion has already occured and about to finish. Please correct me if im wrong.
  21. Hi everyone, I am trying to use a grain simulation to create a sticky gum effect. (like this video) but I have a problem with the meshing. To create a skin out of my grain I first convert my grain to vdb (with vdb from particlesfluid) and then I use convertvdb with the polygon polygon option to convert this to a polygon “skin”. Everything looks perfect in the viewport but when I try to render, it is inflated at rendertime, ie: it’s not a perfect match with what I see in the viewport. If instead of grains, I use a sphere that I convert to vdb volume and then back to poly with the same convertvdb node with the polygon option I don’t get this volume increase at rendertime. See yourself: Is this a bug? Do you know any workaround I could get mantra to render the same result as I see in the viewport when using grain as a source? I saw this thread where someone talk about creating properties in a shader to get to render vdb isosurface directly without converting to poly: https://www.sidefx.com/forum/topic/29678/ But I still have to investigate that one, looks a bit complicated. As another workaround I could render my sim correctly by writing the vdb to disk and loading it in max to render with vray and it rendered correctly. But still I would like to know why mantra can't do it. thanks
  22. hi there!! I've melted an object using flip fluid solver and I was wondering if there is a way to apply a "low" sim resolution to the "high" (original) mesh. In another project using vdb fracture I could be able to apply the low sim to the original mesh by connecting the original geometry into the second input of convert vdb node and checking "transfer surface attributes", but I don't know why this method doesn't works for me for my flip fluid simulation. If it helps in this video: https://vimeo.com/85149964 The person who upload it, comments this: "I cheated a bit by wrapping the low res simulation to my high res geometry " Can anyone help me?? Thanks!!!
  23. Hi, in another thread http://forums.odforce.net/topic/25294-unrolling-paper-animation/ I've been advised to : "Easiest would probably be to nail your animation, and then add simulation on top of that." in order to achieve a realistic behaviour to rolled-up sheet of paper. (see other thread link for details and hip file) Unfortunately, I'm not comfortable enough with H15 to figure out how to do that on my own. I can animated, I can simulate (a bit), but I'm really wondering how adding/mixing the two would have to be wired. I've tried to read about it, but so far, I've only read about switching from one to another (which isn't what I need), and something about rest and target state, that might be involve, I don't kown : / If you can help.... much appreciated! thanks, cyril.
  24. Snow Sim WIP - Help wanted

    Hey guys working on a snow simulation setup for a student film for second year of my University course (University of Hertfordshire) - Been working on some rnd' and so far happy with results but was wondering if anyone had any idea how to get rid of the crazy/flying like particles in my walking man RnD' - Wasnt sure if more substeps/ constraint iterations / or if their was too much force from the colliding object to the snow - will provide a scene too! - SNOW RND - SNOW WALKTHROUGH TESTS (For the shot in this the sim itself may just include dropping the snow ontop of a building for nice placement and not any actual interaction once stable so these tests maybe slightly uneccesary but would be nice to gage a further understanding!!) Will provide both houdini files if asked, LEFT TEST; 1.4 million particles upressed to around 14million at render time Constraint interations - 40 clumping stiffness - 40 Shock scaling power - 0.8 static threshold - 0.5 scale kenetic - 2 RIGHT TEST; 168,000 particles upressed to 4.2million (bit excessive in the upressing) Constraint interations - 65 clumping stiffness - 40 Shock scaling power - 0.8 static threshold - 0.5 scale kenetic - 2 - thinking possibly my scale kenetic attribute is causing the excess velocity/movement on impact (was testing more constraint interations vs higher particle seperation (more particles) which is more efficient ) - HIP File provided, - Alembic geo file too - https://www.sendspace.com/file/8flg0v RnD_Snow_Walkingthrough3.hip
  25. Flip Wave Layer Tank Workflow

    Hi, I've been playing around with the ocean fx shelf tools a bit and have a couple of questions regarding usual workflow. I want to create a boat traveling over a static grid with waves, so combining the ocean spectrum / evaluate sop with flip sims seems like a good idéa, and it seems that this is what many of the shelf tools is doing. I found this in the documentation http://www.sidefx.com/docs/houdini15.0/shelf/ocean_differences and from that it seems that the wave layer tank is what I want. I tried to implement it in a little to advanced project for me and wasn't happy with the result I was getting. So now did a quick test scene with a static grid and a object traveling trough it and I still get some weird result. For example to water doesn't seem to close the space behind the "boat". So I started to think if the whole wave layer tank was mostly for being able to get white water on top of the sop geometry from the ocean evaluate node. I don't know, I'm a bit confused. A saw this nice rnd example from Vladimir and from what I can see he seams to use flat tanks and maybe wave tank. I want those continues waves from the ocean spectrum. Do people use some custom setup to continuously advect the flip sim to add velocity to the waves. Or is it possible to combine something like a flat tank to get the ocean / boat interaction and then do some trick to add that on top of procedural ocean geometry? I've attached my simple test with the weird gap behind my test geo boat. Any thoughts or tips is appreciated. Thanks / John WaveLayerTank_BadResultExample_V01_01.hipnc
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