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Found 343 results

  1. Hello ! I am very new to Houdini and I am looking to assign different Rest length values on a cloth, similar to this example https://vimeo.com/369271677. However, so far my cloth gets distorted and triangulated. Could you please point me to the right direction ? ( i can also add my failed attempt if that helps) . Your help is much appreciated!
  2. How to use vellum with falloffs?

    Hello, I am trying to activate my vellum sim only where the falloff is located, in my scene I am using mops but I am not sure how could I achieve this. Any help is appreciated.
  3. Vellum Pile up with seed shape

    Hello, I'm trying to create a pile of seed. I searched and found a topic in the forum said about the candy made with rbd but the candy is much bigger in size than a seed so the number is quite too extreme I gave up and give vellum a try. Right now I can pile it up but for some reason it has strange orient and a huge gap between them I gave up with overlapping and intersect. Now I'm desperate to know how making it looks like a pile Thank you for reading this Pile_ASK.hip
  4. Hi everyone, I'm trying to transfer my guides from a geometry to another one which is located somewhere else in the world space and it works with the guide transfer through uv's matching. The Vellum Sop works fine during the few frames where the second mesh stays still in t-pose, but once it starts the animation, every guide created from the hairgen starts flipping around. I tried to reimport the mesh as an fbx, alembic cache, obj sequence, but nothing actually worked at all, so I decided to make a sphere and made the same process and it worked fine. I don't actually know if it's a problem related to the skin of the rig or I should try another method, maybe through the dop network. Tried on a different file with only this mesh imported and even without the guide transfer it has the same problem. Might need some help for this one, because is causing me headaches. I'll leave the hip file with the alembic mesh if anyone wants to try and solve this for me. Thank you in advance. alem_10_fenrir.abc pr_fr_v005.hip
  5. Hi there! For some reason the vellum weld node completely freezes houdini if I'm using a voronoi fracture (interior surfaces disabled) to split up my cloth before sim. Edge fractures seem to work fine. It seems the "add bend constraints" vop within the Vellum Weld node is the culprit (or at least what's causing the snag). Is there anything I can do to prep the geo before going into Vellum that will fix this? I quite prefer the look of the voronoi fracture compared to what edge fracture produces. Voronoi fracture does work on super low-poly inputs but anything at the level that I'm working with (100k+) is completely freezing the software. Thanks! Edit: Adding a project file here as an example Vellum_VoronoiWeldExample.hipnc
  6. Vellum hitv hitpos Issue

    As you can see I have a vellum sim with collision. But hitv and hitpos is always zero. Dose anyone konw how to get collision event in vellum?
  7. Hello guys, I made a quick example to illustrate my issue. I figured out how to bring the colour values of the different vellum stresses out of the solver, so I can use them in rendering (in my example I am talking about the stretchdistance) I use the attribute transfer and then try to remap the colour range. Vellum uses this purple to red range and I am just trying to remap it with the point vop to a different range but it doesn't seem right. The gradient is different. The blend between colours seems a lot harsher after the PointVop. Attached some screenshots to illustrate my point. I put the hip file in case. Any clues? Thanks test_color_att.hip
  8. Hello all! I have been trying to figure out how to dynamically update the constraints in a vellum constraints property node based off of the distance of the vellum object from a given point in space, but I cant figure out how to make this calculation dynamically in this context. I can measure the distance before and after the vellum solver with a distance node but they only give me static values in the solver context so I dont know how far things are once theyve moved. Havent been able to get xyzdist to work either. Any help would be greatly appreciated as this project is very important to me!!
  9. Hi guys, I want to push a rigid body (a ball), by the vellum grains, but it is not working! Any ideas? Thanks for helping. Vellum_Grains_01.hip
  10. Geo appearing twice in Dops

    hi guys, I have a vellum balloon constraint on my geo. Until there, everything working ok when I press play. I have added an Attach To Geo Constraint inside the dopnet and now, my geo is doubling up when I simulate. One of them behaves with the added constraint and the other one without. Whats wring? Tx
  11. I have this even geometry and want to create a tool, which allows to interactively add variation while these conditions are met: the inner face stays as it is and the surrounding faces remain planar (stretching is allowed). I found this interesting article about polygon planarization and thought I could try it with Vellum. My goal is to create something like this, just resulting in planar faces: I added a facet node with unique point and planar option on to check the result. My goal would be, that the outer faces stay connected. Is there a constraint in Vellum which keeps the faces planar? VellumPlanar_Problem.hipnc
  12. Vellum Pressure

    Hi, I wanted to ask about some of the hidden intricacies of vellum pressure. In particular I recently found out about the @pressuregradient attribute that determines the direction in which the object expands as pressure is applied. I wonder: How is it determined? I suspect something to do with Normals, but then when I visualise the attribute it tends to always have a rough relationship with {0,0,0} - why? This leads to strange inflation especially if an object is off-center and then it trends away from the origin, as opposed to away from its center of mass... Can it be manipulated in the solver? It would be nice to procedurally predetermine the inflate direction, although I'm not sure how to access or manipulate this attribute. Can it be manipulated per frame? If I have multiple objects that start in a rest position and their inflations happen one after another - one ball moves other balls out of rest position for example... Then once the ball that has already been moved starts to inflate, is it computing on the pressure attribute given at the start of the solve, or the one at it's current frame number? I could probably word these questions better and I do apologise, but at the moment it seems I have run out of places/videos to read/listen to. Thanks a lot for your help! Cheers.
  13. Hey guys, I'm not sure why this is happening. But when I rotate an object that is fed into the vellum collision geo stream, my vellum sim geo always falls through it. I've increased the collision iterations to a very high number along with substeps, and still no luck. I've also adjusted the thickness of the constraints. Any advice as to how to avoid this? Thanks
  14. Vellum Collisions

    Hey guys, I'm not sure why this is happening. But when I rotate an object that is fed into the vellum collision geo stream, my vellum sim geo always falls through it. I've increased the collision iterations to a very high number along with substeps, and still no luck. I've also adjusted the thickness of the constraints. Any advice as to how to avoid this? Thanks
  15. I would like to take this value out so I can create a colour gradient out of it and use it in my texture thereafter. I know how to do it with the stress attribute as it appears in the constraints attributes, but I do not have a Bend angle attribute in my solver. Cheers!
  16. I would like to take this value out so I can create a colour gradient out of it and use it in my texture thereafter. I know how to do it with the stress attribute as it appears in the constraints attributes, but I do not have a Bend angle attribute in my solver. Cheers!
  17. I want to use boolean to do soft body bellum, but I don't know what to do if I want to control the string part... I need your help. I also attach a link to the YouTube video that I referred to. Report post I need the part2 part of the video. vellum_duck.zip
  18. Hey everyone, How can I drive a highRes mesh with a proxy vellum sim which tears? I tried point deform but it doesn't work. proxy.mov point_deform_with_proxy.mov vellum_ballon_pop.hiplc
  19. My brain is having an issue here. I have a vellum sim that emits a new piece of geo every x frames. I need to take the final simmed geo (tet softbodies) and point deform the original hires geo. This wouldn't be hard to do the old brute-force way--by the end only four instances have emitted--but I feel like this is something a for each loop would be perfect for. The image attached shows my attempted setup (it's part of a much bigger project, not practical to upload). I bring in the cached sim and blast the elements I don't want for this step. I ran it through an assemble node (because I thought doing for-each named primitive would do the trick here, no success yet, though, so this might be unnecessary). Then there's a wrangle that takes the creation frame (from the vellum path name) and converts it to an integer "num" attribute, which (theoretically) a time shift could read to know what frame to freeze the simmed and source geo to get them to match up and then do a point deform inside the for each loop. (The reason I have to time shift the source geo is that the geo going into the vellum sim was rotating so that each emitted object would come in at a different angle. I referenced copied those transforms to the hires geo so they match in time and space for the beginning of the point deform.) The first (maybe last?) problem I'm having is that I can't get the time shift to harmonize with the for each loop. It's reading the attribute correctly and behaves right outside of the loop. Some other Googling indicates that it has to be connected to the node before the loop, but then I'm having trouble isolating which object to freeze. I've seen similar questions on various posts, but none seem to quite answer what I'm looking for here (or I'm just not bright enough to translate the fixes). Thanks for any guidance on this!
  20. Hello, I would like my drapped cloth to be a bit more pulled towards the bottom when I am simulating and not have it fly upwards too much. see screenshot. I just want the shape to stay a bit more consistent. I know that the arms are pulling the cloth up at some point, but I am sure I can cheat my way out of this!!! I created a @massgradient with a wrangle using the bounding box of my cloth. This feed into my vellumcloth>vellumDrape>DOPnet. So this attribute should be 1 at the bottom and near 0 at the top. How can I multiply mass by this attribute in the DOP? Is this even how I should do this? I tried using a Pop Property inside DOP, setting mass to 10, and in the VEXpression, typing @mass*=@massgradient; But this doesn't seem to do anything, and when I bump the mass to 100, it gets really weird and doesn't do what I would imagine. Any Ideas? If the cloth had a lower resolution, I wouldn't have this problem, but I want to keep this wrinkled look. Thank you very much
  21. Hey magicians, I'm trying to attach vellum wires to an rbd but i'm having some issues, I can't get proper feedback on rotation and stuff, tried searching on the internet and seems more complicated than I thought. Attached is an example, any ideas or tutorials will be super helpful. Thanks! wGrZ5uUdX4.mp4
  22. Hello, I'm struggling one more time with the rest position. It's something I really have problem to assimilate. So I have my vellum hair simulation. Then I applied a wire to create thickness to my rope. I then applied some UVflatten/layout. And then the UV doesn't stick to my rope. I assume I should use rest for that. But it's an eternal misunderstanding between us. Any help ? Thanks
  23. Vellum Collision

    Hello, I have some issue with my flowers colliding with my geo, they are interacting very weirdly with the geo, do you have any clue on what could help? Ps: When i did a test with less flower, the collision was good but with all the flowers, its like the geo repulse the flower making the flower's mesh explode. So, because it worked with less flower i tried to just up the substeps and the collision passes but nothing seems to do the trick. TEST_VELLUM_005.avi
  24. Connecting geos for vellum softbody

    Hi everyone! I'm trying to do a wind effect on this tree which has separated geos in grp. I imported as fbx and made a vellum configure soft body with a POPwind attached to the solver. but when I start playing the separate geos breaks(of course?). How can I make them stay in place? I'm using houdini 17.5