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Found 74 results

  1. Hello, Can there be a way to update the attach constraint points (on collider) on every frame as the collider moves in a world space so that it gives sort of a sliding effect? I tried adding a custom group in the target geo field, the points in the custom group get updated every frame as the collider moves. But Vellum solver is not taking that into account, it holds the position of the constraints created on first frame of sim. any thoughts? Thanks,
  2. Constraint on Grains not working ?

    I have a point attribute set on some particles when they emit, I can't get vellum grains to constraint only the point attribute ? Vellum in DOPs; vellumObject > vellumSolver > Output but I don't see the grains on the particles in the viewport either ? Vellum Constraints in SOP's is fetching the attribute in Define Pieces from Attribute but that attribute is not constrained ?
  3. Hi everyone, I'm working on a little project of mine and I'm using wire solver with SBD spring constraint. I have attribute set up on the points(before the sim), but when I try to feed the strength parameter the expression with that attribute, it acts as if the attribute was zero. The vexpression I use goes like: @theattributementioned * 1000 I've created basic example file of what i mean. The attr “mult” is what I want the strength to be ( for example “@mult * 1000”.) Any input on this would be great Thanks, Hubert wires.hiplc
  4. Packed RBD from Pop Sim

    Happy Friday, Trying to wrap my head around constraining or copying packed rbd's to particles that are moving along a surface. Attached is my test scene please help if you have time! Thanks, particleRbdTest_01.hip
  5. Glue constraint flicker

    Hi, I hope somebody can help me with a glue constraint problem. I have created an animated glue constraint. During the simulation, the constraint keeps flickering on and off between some pieces. Thus far I have tried moving the color transfer and delete from SOPs to DOPs, delete the broken constraints in a sopsolver and change the "overwrite with SOP" in constraintnetwork. Nothing seems to help and I have a feeling it is something really small I have overlooked. I have added a scene file. Thank you in advance. destTest.hiplc
  6. Ran into an issue while learning DOPs. After having setup Vellum in SOPs I'm trying to import the setup in DOPs. At first everything is fine and dandy, but if there is a Transform added to the geometry on object level then only the GEO that's imported into DOPs network is updated. The Constraints are still in their original position. Is it possible to update Vellum constraint location when the object node is transformed? Adding a basic example file with the issue. test.hipnc
  7. Hi. I want to make activation and constraint coexist to get this↓ result. I made RnD, but it doesn't work. How should I modify it? Active_RnD.hip
  8. Hey there, I'm working on a project for my master degree and i'm having an issue with glue constraint in my DOP network. It was working well until I deleted all the geometry and imported a new version of it from Maya. The ball should go through the wall and destroy the tower partially (just the active points), but it just bounces off. Could someone please explain me how to solve this issue? It's really urgent. Attached you can find my Houdini scene. Thanks in advance! Tower_16_more_windows.hipnc
  9. Hello everyone, the project > I'm working on short animations of a shirt flying in the wind. I decided to use houdini to learn it and use the new vellum solver. I managed to have really nice and quick result for most of the shirts but one of them give me some troubles.. problem 1 > One of the shirt is more like a polo so I would like to set differents constraints on the collar to make it more stiff than the rest. I tried to make groups and merge them but I think I'm missing something because it's not working. I can't find any related topics either.. maybe you guys can give me a clue on how to make this work ? I'm ready to experiment I just don't know where to search anymore.. problem 2 > On the same shirt there is 2 buttons. I'd like to glue them to the shirt for them to react like rigid body and follow the shirt mouvement but I don't understand how I can do it and how to place those news constraints in the graph.. First screenshot is a view of the collar and the buttons placement. It's a model from Marvelous Designer. Next a screenshot of the network view and third a view of the collar being not stiff enough ( : I can only do screenshoots of the shirt and can't really share my hip file because the design of the shirt is not supposed to be released yet. Thank you for the reading !
  10. Vellum string constraint break

    Hi everyone, I'm currently having trouble with breaking a vellum string object in half. The idea is to make a saliva strand that's stretching before breaking in the middle. Currently i have a line that's vellum string, attached at the top point via "pin to target" constraint to an animated object. (string constraints are SOP level, fed to DOP node, with "pin to target" constraint done within the sop solver "forces" subnet) Sim follows the object, and i can break the "pin to target" constraint itself via the vellumconstraintproperty node, set to the group with the top point. I tried various ways to group the centre point of the line, and keyframe another vellumconstraintproperty node, but it doesn't work. Can anyone enlighten me on the proper way to break string constraint points in a keyframe-able way instead of just using stretch stress? Thank you very much in advance!
  11. Vellum Cloth Eyelit

    HEY everyone, I'm trying to recreate a metal eyelit in a cloth and I am going about this using simple cloth. so far I have a pretty nice working file but my cloth starts wrinkling almost right next to the eyelit. I am trying to make a fall off on the outside radius of the metal eyelit so the fabric has more integrity to it around the eyelit/is more stiff and then gets more flowy further away from the eyelit. I am also seeing intersections with the cloth and the eyelit ( I think I need to model the eyelit properly so it doesn't intersect from frame 0 into the cloth or it wont recognise that it's a collider) Anyway I'm very, very new to houdini and have come from c4d so I was wandering if you guys could take a look at the HIP file I've uploaded and tell me if I have the correct setup and how I can make the cloth around the eyelits more stiff so all wrinkles eventually falloff to 0 before it hits the eyelit. Using vellum simple cloth btw with attach to geo constraint. Cheers eyelit.hip
  12. Hi, please see the attached Cinema 4D video of what I am trying to replicate in Houdini. I want to interactively position an object on a surface using handles. I made some progress with the Creep SOP, but it has several limitations: it deforms the source object, which I don't want it doesn't have viewport handles, so I have to edit the node parameters, which is undesirable (I have a lot of objects to manually position, so I want to make it as easy as possible) it doesn't work with polygonal objects I don't mind using VEX or an Attribute VOP to achieve this. Thanks. Slide_on_Surface.mp4
  13. Hello! I'm messing around with bullet constraint networks and I can't figure out how to connect a bunch of points to a single point... basically one source point and multiple paths from it towards each packed piece. Connect adjacent node doesn't have this behaviour. The idea is to connect a fractured packed geo with many points/parts to a non fractured packed geo that has just 1 point/part. I know this will requre some kind of wrangle & coding is not my strong point :| ... any help woud be appreciated! Thank you for your time I appreciate it! Attatched a simple scene, it's just missing the 2nd constraint network. polyline_constaint.hipnc
  14. Hello I just followed tutorial about Bendint Metal using hard constraint. (www.youtube.com/watch?v=38RhntxXcMI) and had some problems with setup hard constraint and need your help TT In my scene, I setup my hard constraint like left screenshot(red lines). and just like the tutorial, write vex codes for make hard constraint where middle of each constraints. This is guide geometry of constraints in dopnet. Left side is the tutorirals constraint one and right is mine. Modeling is different(I create my modeling my own), but I don't think It makes those difference in constraint. I set up Rest length option same with tutorial but what are those additional constraint points ?? I think those points causes difference with the tutorial so I need some helps to get rid of them. How can I get rid off them ? Sorry for my English TT
  15. Glue RBD on Vellum

    Hey guys, is there way to do this? I have to rip an envelope and it have that wax sealing it. It rips just where the wax is. The wax doesn't break but it have to influence the vellum in some way. Anyway, just a simple test with RBD and Vellum interacting would be awesome. Thx
  16. Hi, At this point I need a new pair of eyes on this one and maybe a new brain. I have a simple test scene with a rbd ball smashing a wall, the wall is holding together with ConeTwist constraint. I then use the good old sop solver to 'removeprim' the constraints when the angle is larger than X. I can see the Angle attribute in the spreadsheet and all, but for whatever reason (I know it's a very simple one), the constraint bend but don't break! If someone as a few minutes to spare and take a look it would be much appreciated. Sorry if I sound sarcastic but I'm getting frustrated by my own stupidity! coneTwist_test.hipnc
  17. Difficulty breaking hard constraint

    Hi guys, I'm having trouble breaking my hard constraint. I'm currently working on a metal destruction and upon impact my constraint doesn't break eventhough i give a treshold in which I want my constraint to break. I'm using a wrangle with: if (f@distance > ch("break_me")){ removeprim(0,@primnum,0); } but my hard constraint stay together. Thanks
  18. Spring Constraint

    Error - Glue constraint references unknown object Would really mean a lot if someone could take a few minutes to look at this file. I was trying to recreate richardlord's spring constraint thingy, but had trouble even beginning to get it to work in the first place. I think there's some changes in constraints from 15-16 (im working in 16). I should have the name attribute matched up to all my constraints and all my objects as the same, but for some reason I get an error with, 'unknown object'. I thought it may have been that the constraint was looking for @rest? Not sure. Very new to creating attributes that get used in dops, I appreciate any insight. springConstraint.hipnc
  19. vellum hair break [SOLVED]

    Hi, exploring vellum i'm trying to break an hair geo by enabling the "break threshold" option in the "vellum constraint" SOP. I must be missing something on the constraint workflow of vellum because it has no effect at all on the sim :'( I'd be curious to know if any of you managed it ! Thanks vellum_hair_break.hipnc
  20. Vellum Cloth and String weld

    Hi guys, I'm playing around with vellum but something is bothering me: I want to attach a string to a cloth but I cannot do it if they are 2 different vellum objects in DOPs The example file will be much clearer than what I write but the question is: Does all the vellum objects need to be merged to build a constraint network, am I using the wrong method meaning I should create the constraints in another way ? Thanks for you help ! cloth_and_string_01.hipnc
  21. i am personally interested in setting up wire constriant using old apply relationships method, i am curious about the efficency and other aspects compared to constriant network, did someone already test it in some big projects, could you please share the experience, thanks a lot!!!
  22. Hi all, Is it possible to constrain packed RBD objects to the static deforming or animated obj? In TP its work by default without any problems, but in houdini I cant find solution. Thanks!
  23. Hi, I have been searching for a solution to this RBD problem for a few days now and can't seem to get this to work fully. I attached a scene file with some descriptions inside to help explain. The basic notion here is to dynamically create spring constraints when some packed rbd cubes get close enough to a collision sphere that is at the origin. I can't seem to get the constraints to work unless they are created/exist on frame one. I create them inside a sopnet in the dopnet and use a sop solver to get them into the constraint network setup. Haven't tried creating constraints like this before so might be totally wrong in this approach. This setup works as long as all constraints are there on frame one, and then in the sop solver I set a high strength if the cube is close enough to the sphere, which semi locks the cube to the contact point on the sphere, which is what I want. However if you change the search radius on the wrangle node in the sopnet so that only the closest cubes to the sphere have constraints on frame one, then only those constraints ever evaluate. Any help sorting this out would be appreciated. I couldn't find anything in other posts to help with this. Most posts I saw were about dynamically deleting constraints and not creating them after the sim is going. Thanks E RBD_CONSTRAINT_TESTING_CLEAN_V2.hip
  24. Hi Guys, I'm trying to create a constraint network for simulating Car Suspensions, but with no results. I just need a simple "spring effect" between Body and Wheels (please find a video example attached). How I can do it? Any suggestion will be really appreciated. Thank you! I've attached a simple file test I'm working on. Car Example.mp4 Cartest.hip
  25. Well, I went out into the RBD Constraint Forest Unprepared, and now I am lost in the woods. Any help would be appreciated. I'm trying to do something that should be fairly simple, and most likely is, but I don't have the combination to the Houdini lock to get the setup to work. In the example file I have an rbd box that has 10 faces per side that have been made into unique faces. They have glue constraints holding them together and are a rbdPacked object in my dopnet. There is a low rez smoke sim that pushes this rbd box into a collision sphere that is above it, and when the geometry collides with the sphere, some of the glue constraints start to break. All I wish to do is apply either a gravity force or a popForce to these rbd pieces that have lost their Glue constraint. I want the main chunk of the rbd box that still has a bunch of pieces glued together to keep on moving with no gravity or popforce. I might be trying to go about this the complete "wrong" way since I have very little experience with Glue constraints, But I see data in the geometry spreadsheet while in the dop net called ConstraintGeometry and this has a primitive group called "broken" which contains the glue constraints that have been broken due to collision. I would think I would want to try finding out which rbd piece that broken constraint belongs to and then use that to create an "applyGravity" group of rbd pieces so that I can do what I want to do. I just don't know how to do this in dops. Is this something that needs to be done in a sopSolver or geometry wrangle or....? I'm not to familiar with how to read data from the ConstraintGeometry and apply it to the Geometry data. When I middle click over my rbdsolver, it shows the main rbdpackedobj1 with Geometry and then CosntraintGeometry below it. They are like separate entities and I'm not sure the best way to get access to both in one node, if this is even the way to do it.? For example if I change a geometry wrangle to point to "ConstraintGeometry" instead of the default "Geometry", I can then read and manipulate data on the ConstraintGeometry, but then don't have access to the main rbd "Geometry" that I am use to normally working with. Like everything in Houdini, there are probably dozens of ways to go about this, I tried about 20 yesterday, without ever getting one to fully work. I ran out of search phrase ideas to try throwing at google after about the 6th hour of searching. Maybe using some of those copyData and applyData nodes would get the ConstraintGeometry data onto the Geometry stream so they can both be read in one wrangle or maybe that too is a completely wrong direction to take. I don't want to speculate any further since you could try things for a week and not get it to work if it just isn't the right approach. I love Houdini for its vastness and unbelievable tool set, but man, it can destroy you if you don't know how to do what you want to do, and can't articulate it well enough for a search string.! Thanks for any help. E rbd_constraints_v01.hip
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