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Found 156 results

  1. Independent surface tension

    I am trying to achieve the effect of having a solid piece of geometry sitting as a fluid, being brought in by either volume source of pop source. This initial piece just has fluid ripples. The second part is I have emitters in the same dop network that are there to create a dripping effect. So it looks like this liquid that is holding shape is dripping. The problem is that I cant seem to create independent surface tension for the two separate sources. If I increase the surface tension to what I need then the main piece of geometry gets washed out. I have been looking for a solution to this but nothing comes up for Houdini 18
  2. How to fracture bricks for sim?

    Hey guys long time lurker first time poster. So I have a brick wall created in Houdini and I wanna blow it up. Got my texture projected and everything. The wall consists of several rectangular boxes all made in Houdini. Projection done in Maya. So now I wanna know the best way to fracture the bricks while still getting that interior detail on the "inside" faces of the bricks. Moreover, once fractured, how do I apply texture on the inside pieces? I know we gotta separate the inside and the outside groups first and then apply the material accordingly. However, when I apply the material (with a broken brick texture), on the inside group, it just renders a single flat color (the color dominant in the texture) . UV unwrapping the inside group and then applying a texture also doesn't work (renders out a single flat color). Maybe I'm doing something wrong Idk. So what is the best and most efficient way to fracture bricks and texture the inside groups? Would love it if you'll could share some tips to help me out. Thanks!! EDIT- I tried using Redshift. Thought that would be important to share.
  3. Fluid coupling

  4. pyro distributed problem

    is pyro distributed work with checkpoint ? i have 2 slice,output the .sim file with $SLICE variable work ,but when i try to resume the sim with this .sim file it will stuck. what i doing wrong?
  5. Hi Houdini guys, I'm doing a Pyro simulation using the instance function because of the smoke&fire of a long trail. I've instructed to create 10 clusters, but there are more than double as many containers created in the scene. The reason is that I'm increasing the sub steps in Dop network. I confirmed that the sub-step of 1 produced the specified number of clusters. However, I need to keep the substeps because the emitters are moving fast and the flames need to look nice in my scene. Is it possible to generate a container only for integer frames? If u have suggestion, I'm highly appreciate it. Thanks!
  6. Trouble with exploding RBD SIM

    Hi all, I'm still pretty new to Houdini, but I offered to do my friend a favor by attempting to sim a spaceship crash for his short sci film. It was more of an excuse to learn RBDs in Houdini than anything else, but now that I've invested this much time I really want to make it work. Anyhow, I started with Steven Knipping's Applied Houdini Rigids III Vehicle Destruction course and once I finished that, I tried replacing the supplied helicopter model with a spaceship that I modeled in C4D using a Kitbash kit, so I imagine the geometry shouldn't be an issue. It would appear that I'm very close to getting a workable sim because I got it crashing and denting with the original animation that I set up for the ship. However, I've been running into a bit of a snag if I change the crash animation. For whatever reason, if I move the ship at all to match any of the tracked alembic cameras I was sent, either by changing the keyframes of the crash itself, or even by simply attaching the entire animation to another null and moving it in the scene, the ship totally blows up. You can see what I mean in the last 3 previews found in VFTV\render of the attached project folder. Maybe I'm missing something very basic, but as far as I can tell this shouldn't be happening, as my understanding is that the hard constraints I'm using on most of the ship aren't supposed to break unless I tell them to in the art directed cuts section of the frac SOP. Anyway, the first preview in the VFTV\render folder shows that the sim more or less works with the camera matching but without denting, and the second shows the crash with denting but with no camera matching. But, for whatever reason I couldn't get the source tracked cameras working directly in Houdini, so I took them into C4D first, changed the resolution and alembic camera scale, and exported them at .01cm from C4D, and after that they seemed to line up in Houdini once I changed the camera view resolution to match. However, my troubleshooting brain is telling me that I might've messed something up during this process and perhaps the explosion is due to mismatching scene/camera scale issues with the alembic cameras that the tracking artist sent causing the sim to be calculated differently. I'm not even sure if the C4D camera scale option affects the sim in Houdini and/or C4D, but scene scale certainly does, and if the imported camera scale is messing with scene scale, then maybe that's the problem. That said, I don't think that's the reason, because if I leave the original animation alone it seems to sim fine even with the new cameras. And, I believe I'm matching the scale correctly and using the right conversion which is supposed to be .01cm from C4D to Houdini. I've also messed around with exporting different camera scales and scene scales out of C4D and importing the alembics back into Houdini using several different methods, all with the same result. But, I realize it might help me to know more about which software each shot was tracked in, so I'm double checking with the guy at Framestore, who did the tracks, regarding the scene scale conversions. I was thinking Syntheyes might be different from Nuke for example. That said, I would be eternally grateful if anyone was willing to look at the project and let me know what they think the problem could be. My hope is it's something stupid on my part, and not some overly complex issue. Here's a Dropbox link to a reduced version of the project with all the assets VFTV_Smoldering_Wreckage_1_200813_v001.hiplc
  7. Hi, I am importing an Alembic particle sequence from realflow. Shows up great in Houdini, no problems there. I want to 'mesh' it, I was thinking I would convert it to VDB and then to polys to have maximum control however the 'VDB from Particles' node is not taking the alembic particles (ie. nothing happens). Do I need to convert them to something else before? Am I approaching this completely wrong? Much obliged,
  8. Help with explosion sim

    Anyone know what parameter(s) is causing all the smoke to quickly fall towards the end of the simulation? explosion.mov
  9. VELLUM PRESSURE

    Hi I'm trying to control the restscale attribute using a custom attribute, so i can animate a noise and have it inflate depending on the color / custom attribute. I have added a vellumconstraintproperty and tried to use vex to transfer my atribute. But this is where i'm getting stuck. any help would be amazing. thanks VELLUM_INFATE_TEST_04.hiplc VELLUM_INFATE_TEST_04.hiplc
  10. Hi i have a question regarding narrow band in fluid sims: I am using an ocean source for my flip tank as source but how do I calculate the layer size in oceansource (thought its particleseperation*gridscale*narrowbandwidth) - because my fluid keeps dropping down when sim is running
  11. sliced ribbon cloth effect .

    Hi , is there any guide or starting point to achieve this kind of effect in houdini like this tyflow example ? https://www.instagram.com/p/Bm8nHNfApwE/?utm_source=ig_web_copy_link the confusing part for me not the sim itself , it's how he slice the geo in a continues sliced way ? any input is really appreciated ?
  12. Colored smoke gasupres with Redshift

    I'm working on a colored smoke sim in H18 and Redshift and I have problems setting up my color grids properly. Running VDB diagnostics tells my values in the range are invalid and my knowledge of how to find the error ends there. The idea with the sim is to create a low res sim, up res it, and add colors from the Cd attribute. Does someone know how to set up this sim properly? blueGreen010.hiplc
  13. Hey there! I'm quite new in Houdini. I do not really like to ask questions, I rather tend to find answers by myself. But sometimes I hit the wall. This is the case I need your help guys. Im trying to make RBD sim in DOP NET with the simple spheres. My goal is to have variable scale and color of a sphere according to the noise. I manage to get color with POINT VOP in SOP SOLVER with MULTI SOLVER. But I stuck with the scale of a spheres. They inherit pscale from a GEO level. I would like to use pscale in DOP NET and manipulate it with the POINT VOP. Any ideas how to achieve it? I tried to make it with the particles, like in this tutorial https://www.youtube.com/watch?v=qXoSEnh94YQ&t=246s But particles tend to move erratically and not act like proper RBD. Balls on plane.hipnc
  14. Attach Camera to Boat

    Hey All - I have an ocean in Houdini with a boat floating on it. I'd like to attach a camera to the mast, but can't figure out how to do it. Any ideas? Thanks!
  15. Smoke collison

    How do I set up 2 different emitters shooting smoke at each other and colliding?
  16. Hi guys, I have a rigid body sim with constraint network, I want to access the previous frame and current frame data of the constraints (impact, forces etc) inside a sop solver in DOPs. Currently when I call the attribute in a wrangle from the relationship geometry node I don't know if it's current frame data or previous frame. How to get both the current and previous frame data in a wrangle in sop solver in dops?
  17. Hello again Guys. So recentrly (3 hours ago) I swapped to RS because my Mantra render was taking over 2 hours per frame. I started shading everything and had some problems with the volumes (Which worked in mantra perfectly fine) Scene View IPR with an area RS light with contribution set to .5 (to test) The setup As always, Thank you guys
  18. I have a scene where I am dropping a bottle into a flip tank all at small scale. The issue im having is that I am getting a quite a large space/void between the bottle and the liquid. Im trying to reduce this and make the liquid hug the bottle more in the beginning and not blow outwards and make this gap. The setup is an RDB of the bottle falling using gravity from around 10cm into the tank, both the RDB and Flip have been slowed down to 0.025 in time scale. I tried a number of things like lowering the velocity scale, upping the subframes from 10 to 30 in the RDB and upping the subframes in the DOP network to 4/5, and changing the surface tension and viscosity, but it still happens. There is no problem with the collision guide and I dont have any sort of surface offset on that either, it matches the bottle perfectly. You can see in the attached screen grabs that the bottle has barely entered the fluid surface but has created a large void underneath it blowing out the liquid. This is the sort of splash im aiming for: https://www.youtube.com/watch?v=npAuLi1y5AA Dramatic but close and not blowing out internally too much. I know my bottle is a different shape to that reference but my sim seems way off and I cant seem to figure out how to lessen that gap. Any suggestions I would be very welcome as nothing I seem to try is making the gap any smaller. Thanks!
  19. Hi, I've scattered 5 explosions to points using a switch node and a foreach loop. The explosion are randomly assigned to point but I need to have them offset at random as well. How would I go about achieving this? The effect I'm going for is flak in a WW1 scene but at the moment all the explosions start at the same time
  20. Pyro sim steppy look

    Hello again guys. So I am trying to do a pyro sim for some pod doors (Some fbx I downloaded) but I find myself with that problem. It is not the first time it happend, It might have something to do with the scale but I dont know. Can you guys take a look? Houdini.rar
  21. Hello, this may seem odd for majority of you who live in a country with constant electricity. I am making a rigid simulation of say 700 frames. I have already cached it up to 400 frames before our power supply got cut off and my pc went flat. Now, if power is restored and I change the frame range on the file cache node to 401 - 700, and then click save to disk. The dop network would start from frame one until it gets to 400 and then start caching. My question is this, how do I tell the dop net to start from frame 400 using the last positions of all rigid pieces already cached as the start point ?? Thanks
  22. Transfer Low to high sim - vellum

    Hello, i have a vellum source emitting a low res model every 10 frames. How can i exchange the low res output with the high res version? this is my setup, i am working on Houdini 17
  23. Pyro Sim not rendering properly

    So i got some help from a guy on here for my uni project. The file he gave me looks amazing but when i come to render it, the fire doesnt show at all. Does anyone know how to resolve this?PyroSim.zip
  24. Pyro Sim

    So im working on a pyro sim that is on 6 bowling pins with a juggling animation on them. For some reason the fire isnt really showing up at all on the pins and i cant figure out how to fix it. I would appreciate any help. PyroSim.zip
  25. Helloooo just trying to make it so my hair doesn't have to fall into place every time i start the sim. Thanks!
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