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Found 147 results

  1. I've seen this setup in a few projects VDB from Polygons > create a Distance VDB (SDF) VDB Smooth Convert VDB > convert SDF to Fog Name > rename sdf group (created in Step#1) to density Why not skip SDF altogether and simply create a Fog VDB in Step#1?
  2. Heightfields

    Hey there! Okay so I have got a grasp of how a heightfield works but what I am trying to do is confusing me. I have the sole of a shoe and on one surface I want it to have the heightfield on. How do I merge the heightfield with the surface? I have used the project node but I still get the square. I also used attributes from volume and then a point wrangle to transfer the height to the Y position but It affects the whole of the geo. I need help! Mountain_Duality_Sole.hip
  3. VDB velocity half circle?

    Hi! Houdini beginner here. I have multiple curves that spin around that's being converted to VDB for smoke sim, but I'm getting this weird half-circle from its velocity. It almost looks like it's being clipped. How do I fix this? Thank you! vel_zero_on_z-axis.hipnc
  4. I have a smoke master cache at the origin created in houdini (vdb). I am positioning this cache in the world (attaching to anim) using copy to points with orientation. I would like to cache out only the point (with position and orientation attribute) Import that point in Maya, and instance the master cache vdb directly from disk with the correct position and orientation. Could you please suggest me how to achieve this? Context. This master is used across an entire sequence. For every shot is placed and re-cached out in position. This is very inefficient, both time and disk storage wise. An instancing system would be a true game changer.
  5. Smoke Sim- vel not coming through?

    Hi! Houdini beginner here. I created a custom velocity using pointVOP and added onto VDB surface attrib point.v as vel. When I middle-mouse click, it shows that vel exists. I have it scaled higher than 0 on the volume source in the DOP network and set "Add" for the operation option, but it makes no difference in the smoke sim. There's supposed to be a noise pattern in the velocity, but it's only taking into account of gravity. If I disable the gravity, nothing happens to the volume (the volume surface get steppier? but it doesn't push the smoke or anything). There's also a custom temperature going into DOP, but that one works fine. So I think I missed a step somewhere when bringing the velocity into the DOP network.....What am I missing? Thank you!!
  6. Hi everyone, Basically what I am trying to do is simple but haven't been able to find a way that works. I have an animated object and I converted it into a VDB to eventually turn it into a cloud. However, once the object is converted into VDB and it moves, the VDB starts moving through the object in World Scale and flickers , is there any way I can have the VDB stick to the object? Thank you!!
  7. Hi, Im new to arnold for Houdini and want to know if there is a way to directly specify a vdb volume in the string path instead of a file on disc. for e.g.: I tried: /obj/cloud/OUT op:`opfullpath("/obj/cloud/OUT")` op: /obj/cloud/OUT ( without any luck) thnx for the help!
  8. Hey! I don't really know how to properly describe my problem. I have created a cloud vdb from polygon geometry. Everything works and looks fine but when I imported it into c4d for rendering I noticed I only got a "real" volume export in some areas. I tried to export and re-import my vdb in houdini, it looks perfectly fine. But as soon as I create a Points from Volume sop I get the same issue again. It seems like there are only certain areas where "real" volume is created. I have no idea why this is happening and need a cloud effect for a project asap. Would really appreciate ANY help.
  9. Hi there, I have a scene that has some noisy ground fog that helps establish the atmosphere of the scene. I am working with a single frame of vdb that was created with some volume noise. It's simple but it works great for stills! I am trying to come up with a good way of advecting it, or at least applying some form of subtle animation that will make it appear more dynamic in motion. It's fog, so it doesn't need to be anything too crazy. Curious what your solutions would be to this problem! Cheers
  10. Hey guys, I'm having some issues with a FLIP collision, seems my VDB collider boundaries are affecting the sim, anyone knows what can be causing this? I'm using static object + static solver with a proxy volume as collider. Thanks!
  11. Hello I am trying to mix/combine the density and colour of two different VDBs into one VDB in Houdini (image 1, file attached). For the most part, this is working as desired but there are two main issues: 1. Pink fuzzy edges around the blue VDB - How do I get nice clean edges where the blue VDB smoothly fades out to transparent? (image 2) 2. Blue VDB does not go all the way to the border of the pink VDB - How do I make sure both VDBs finish on the same outside border? (image 3) I have tried adjusting the voxel size, changing the set up of the VDBs (ie. the exterior/interior band voxels, fill interior) but I can't seem to get it working the way I want. Can anyone please help me? I have only been learning Houdini for just over a month so example files would be helpful. Thank you! Mix VDBs.hip
  12. Hi, A simple question but I can't seem to get the answer. I need to convert a sphere primitive to a volume, when I do this with a VDBfromPoly instead of the VDB showing up as a perfect sphere I get this low res sphere similar to what you would get with a low frequency poly sphere (see screenshot) Is there something to tweak to get a perfect sphere, or is there a better way to to convert from a primitive straight to a volume? P.S. The reason I need to do this is because Im copying a few hundred thousand spheres to points and if I try to do this with poly spheres houdini crashes always.. only way I seem to be able to do it is by keeping the original sphere a primitive. Thanks!
  13. Volumetric Temporal Deflicker 2.1

    Digital asset download at Orbolt! Enjoy https://www.orbolt.com/asset/RodTD::Rod_vdb_averaging
  14. more advanced vdb to spheres?

    Hi Houdini community, I`m wondering, what is a good way to fill a geo with spheres, just like VDB to Spheres SOP, but with greater control and without intersection. At my studio, we just finished a project, involving close ups of beer foam (bubbles in it). My problem with the node mentioned earlier is that I can not choose a distribution ratio between the pscales, like a ramp would allow me. Now I`m trying to come up a solution just for fun. My first thought would be to scatter in a fog, and than relax is after generating pscale, but that pushes out the points from the original geo to much. Anybody got an idea? Thanks for reading this.
  15. Looping rain drips on windows

    Hi there, I've been following this excellent tutorial on creating streaks of rain across windows: https://www.youtube.com/watch?v=AwsYhKy1K5g It's working well and i've made a few adjustments to fit with the rest of my scene, but there are a few things I was hoping someone might be kind enough to help me with: 1. The tutorial author uses an expression to offset a resample node to create the animation of the drops falling - how would I adapt this expression so that I can create a seamless loop? 2. More simple: the drops created by this method are fully sphereical, I need them to be flat on the edge that touches the window - how do I use a vdb volume to cut the whole thing so the window facing side is flat? 3. Just trying to get the static drops to be a bit more random in size and guessing at the expression, currently @pscale = (rand(@ptnum)*(0.15)+2.2) -1.20; - i'm just trying to pick a random float between 0.1 and 1.2 I've attached my scene file, any help is very appreciated. window4.mp4 raindrops_001.hip
  16. Hello houdini guys, Im trying to simulate physarum polycephalum growth, but unfortunately it has some small issues. I would like to ask U on 3 main questions, if u will able to help me with any of them, it will be very helpful for me! 1. I have problem with VDB convertion as U can see on the picture, the distributed mesh (from wire extrude) is broken and VDB looks like particles. I dont know how to fix that. 2. In my file (I marked it with red network box) the small vein system of my slime mold, and I would like to connect it to the growing solver, but I dont know how. Basically I need this small veins with same growing properties like the big one have. 3. And last one is is possible to make the slime mold more "fat" on the edge? I dot hnow how to select this part of mesh? :/ ( like onreference picture) Thank U guys for any advices! Im looking forward! Bye! Physarum.hip
  17. post process volumes

    Hey I'm looking into some volume post processing, I need to be very art directable on a volume after the sim so basically what I need to do is define areas where I need to increase density for instance, or decrease it. which is the best way?
  18. Procedural rocks carved in vdb

    Hey guys, I'm trying to understand how to make procedural rocks carved in volumes using the technique exposed at Siggraph by Saber Jlassi. You can find the video here Hi approach is to use a combination of worley and aanoise in VOP. The result should look similar to this image. I joined the image of his vop network too. I didn't manage to reproduce what he is doing, been trying all day. Is there anyone here who would be up for giving it a go with me ? Any help would be very much appreciated. Chris
  19. create interactive Fog

    Hi All , I am doing some test on interactive fog which would be low ground Fog and I want to show some interaction with moving character . Any Help ..would be highly appreciated !!!!
  20. RBD Fracture Geo - Retain UVs

    Hey, so I was curious how some of you may approach this - fracturing some dirty geometry (feels nightmarish so far). Tried cleaning it up procedurally as best I could - filling lots of open holes, and vdbfracture to retain uvs. But starting to suffer some errors that I can't seem to decypher. Only thing atm in my head is do this process per connected piece and distribute fracturing based on area. But major head ache just seems working with non water tight models and fixing them crudely then getting to all these areas of trouble for simulation or fracturing, not sure if there's a better solution other than model it water tight to begin with. Here's just a segment of it. I feel I'm perhaps over complicating it in my head. Well cheers if any help max_rbd_fracturing_scenario.hiplc
  21. cloud with interaction

    hey! I'm doing some clouds (static) and I need to make one of them "dynamic" as a character jump out of it. since I created them with some geos, then convertem into volumes and applied some noise, so no solver obviously, I'm looking into some tips to convert it into a source for a dynamic cloud cheers
  22. Hi everyone ! As says the title, I want to export scalar values attached to voxels (VDB) into a 3D matrix because I want to access to voxel data into another software (matlab) does someone know how to do that ? thanks ! Alex
  23. Hello everyone, I am currently a student and a young Padawan I block a lot of candle effect and I need your help ... My candle effect works well in the scene view but I have a lot of difficulties to find the same effect in Arnold on Maya despite exporting to: "convert VDB" "VDBvectorMerge" "Primitive" then my cache VDB ... So on Maya I can not seem to recover the same aspect with a arnold volume and my aistandardvolume ... Will anyone here help me? I leave you the scene to better understand ... candle.hip source_volume_cache.7z
  24. Hey guys, I have a quick question about the polygon soup meshes I'm getting out of Houdini. I'm getting mesh popping when I convert it and send to C4D for render, they look like the attached IMGs. I included my set-up in there as a rough guide but I think there's something I'm really overlooking. I'm kinda new to Houdini still and would really appreciate a kick in the right direction of how to solve this in terms of the way I'm approaching 'skinning' the particles. Thanks

    Hey ! So I made a particle simulation in houdini, from a base mesh then I convert the particles to VDB and then back to polygon with the the convertVDB node. I exported a frame in OBJ en opened in Maya, next to my original base mesh. I apply the same arnold volume texture to both, and I got 2 totally different looks. How is this possible ? They are both polygons ? (The one in T-pose is the original base mesh).