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Found 51 results

  1. 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
  2. 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
  3. Is it possible to use at point group from sop level, to constraint points in a dop (wire sim) with the "SBD Pin Constraint", instead of manually typing in all the points, that has to be "Constrained Points"?
  4. Hello, i am currently working on my final student projet where i make a plane crash with Houdini. I base the workflow of this project around the RIGIDS III tutorial by Steven Knipping. Everything is working fine until i bring in a simple glue constraint, and when the simulation gets activated at a said frame the simulation simply does not happen. It works when i disconnect/disable the constraint. I already tried to unpack the alembics upon importation with the alembic node but that didnt change anything. What is weird is that everything was working fine when i used the model given with the course. I haven't really found anything that helped me online, so hopefully one of you can help me with this issue, i would appreciate it A LOT. I will attach the files down below. Thank you ! plane_sim.rar
  5. FEM in 16.5

    Hi. Im trying to constraint points on a FEM object in H16.5 but cant select any points to constraint. Have anyone had this issue? I use the shelf tools, then do the following. 1- Constrain points to target 2- try to select objevct i vewiport, dont work, have to select it in Node menu/dop menu 3-cant select any of the points on my object in dops. In H16 i animated the Geo in sops, then added constraints to some points in Dops, then it worked. But i intalled 16.5 today, and i cant select any points. Im kind of lost. Ive read about upodates in H16.5 put i could not find any answer. Let me know if i didnt explain this good enough. SOLVED: i had to use a visibility node in sops to mark my tetras. fem_poins_issue.hiplc
  6. Hi, In Max we use a lot of link constraints when it comes to technical Animation. E.g. a roboterarm grabs and moves something from position A to position B and during the movement the object that is being moved is constraint to the roboarm. I attached a Video to make it more clear. What is a nice way to do something like that in Houdini ? I looked at the Rivet Object but I could´t find a way to animate it. I would be thankful for some input. Jon Link_Constraint.flv
  7. Hey all, Apologize in advance for the noobiness, but this must be the right place where to ask. I'm trying to instance more than one Spotlight to a deforming geometry. What I've done so far was scattering points over a mocap and riveting a spotlight on a single point. My question is: Is it possible to procedurally instancing spotlights on every single point, possibly following the normals of the deforming geo? Might sound a tricky question so that's my .hip file attached {{ dnw5.hip }} Much love
  8. I'm pretty new to Houdini and I'm not sure whats the best way to approach this effect. Right now I have a thin cylinder I am using for the string and I converted it to organic tissue in the shelf. then I have a big soft body that I also converted to organic tissue, and placed it on a rotating platform. All of that works great and looks nice when it deforms. But I'm not sure how to attach the rope to the soft body so that it will begin to wrap around it. I tried using a SBD spring and that had no effect. Then I tried using the Stich cloth tool from the shelf. That worked great in "hard" mode, but the two soft bodies stopped colliding. Then I tried constraining the rope to a rigid body, and the constraining that to the bog soft body, it worked but the rigid body kept dragging everything around randomly. I attached my scene of what I have so far. Thanks! rope.hip
  9. Constraint RBD to Cloth (or Grains)

    Hello guys, How can I attach a rigid body object to a piece of cloth? I'm a bit lost on this. I tried cloth and also pbd with no success, now I have no idea on what i should try. There's a file attached (using grains). It's a starting point if anyone can give it a try. Cheers - Alvaro rbd.to.grains.v1a.hiplc
  10. So i have this sim and i would like to dampen or even remove the movement in the Y axis since it makes the concrete look light and weightless. I was trying geometry wrangle and anchor nodes, (not really sure how to use either), i wonder if there is a place where i can simply put a simple VEX line like @v.y = @v.y*0.25 or something similar. Can someone point me in the right direction on where can i do that and where should i plug such node in case there is a way. untitled.mov here is the Dopnet right now
  11. Hi everyone! I'm relatively new to Houdini, and I came across a tutorial which explained the bullet solver for H13. I am trying to recreate the effect that he got at 53:15, where primitives were deleted from the constraint network when a force over a certain threshold was applied. tutorial: As I understand, the SOP solver was changed in H14, and I therefore don't have the object merge node that he has. I downloaded the example HIP file and copied his node into my own project and managed to get it working, however I'd like to know how it actually works, rather than just copying and pasting! The data that the node is bringing in, is as follows: `stamps("..", "DATAPATH", chsop("relnode") + ":Relationships/" + chs(chsop("relnode") + "/relname") + "/" + chs(chsop("relnode") + "/relationship/dataname") + "/Geometry")` This isn't like anything I've come across so far in houdini - if anyone knows what this means, and could explain it I'd be very grateful! Best, Stephen
  12. Grains - Disable Constraint Averaging

    I posted this on the SideFX forum but haven't had any response so I thought i'd try my luck here: I'm getting some unbalanced forces when using grains, its the same problem as described in the grains masterclass around 32:50. As Jeff says the solution is to disable constraint averaging and then insure all the internal forces add up to 1. I've done this but I still have an imbalance.. I wanted to check which forces are meant to add up to 1, in the video it implies that Internal Collisions + Clumping + Explicit Constraints = 1. However in the help document it mentions that Friction with Particles should be included as well. So should I set Friction with Particles, Internal Collisions, Clumping and Explicit Constraints to 0.25? (
  13. Hi .. I am trying to follow along with a tutorial that goes over wire constraints and pins. I cant get it to work properly. If anyone has any brilliant ideas ... let me know. here is a hip ... wires_3.hip
  14. Hi .. I am trying to follow along with a tutorial that goes over wire constraints and pins. I cant get it to work properly. If anyone has any brilliant ideas ... let me know. here is a hip ... wires_3.hip
  15. Hi I am trying to understand the applyrel node a bit more, and more specifically I am trying to add constraints on the fly by adding points into a group on sop level. half way kind of there but as always with Houdini running into a few issues. If anyone could possible take a look at my scene and point me in the right direction it would be most appreciated. wirescon.hip
  16. Constraint Grains to Animation (targetP ?)

    Hey guys, how can I use this target pins option? I have an animation in sops and I need the grains to be constranited to that animation. I guess the targetP attribute shouldn't come from Sops but I can't find a way to make it in Dops beased on that Sop animation. Any tips? Thx
  17. Hi! I want to attach a geometry (some voronoi fragments in this case) to a moving/deformed mesh, i.e. I want to deform my base mesh freely and the voronoi fragments follow the deformations (Position and rotation or normals directions) without stretch it. I already try it with Point Vop but, how can I send the information of N directions to each voronoi fragment? If I send it with Cd looks like this: I animated the geometry with a mix and a group generated with color. I hope that someone know how to do this. Your feedback is welcomed and thanks so much!! Constraint Obj Test 01.hipnc
  18. Hi does anyone know how can I add a hard constraint between two or more particles ? exactly like RBD objects but it should be work for POP solver. I prefer do this via custom VEX codes for manipulating P or V. Thanks S
  19. Constraint RBD to animation

    Hey, how can I constraint an active RBD object to a static but animated one? For example I want that anchor to be constrained to that ring. A pin constraint just fixes it to a specific place. Tried wires but again this went crazy. So how can I get some realistic motion to his anchor? Also tried the oarent constraint which changes the constraint location from a static point in space to a goal object. Still no luck.
  20. Hi everyone, I made this setup to mix constraints between conetwist and glue, depending on angle value, i set the constraint_name in a sop solver plugged in the constraint network node, it works quite well but the resulting object is floating in the space... is anobody here can check my file and tell me what's going on!!!? apparently its not a subsanple or CFM, ERP issue ( i checked all this parameters and, nothing...) thx by advance, Best regards H TEST_PACKED_CONST_METAL_V002.hip
  21. Hi everyone! can't figure out why my cone twist constraint collpase at frame 2..., apparently this constraint dosen't care about restlength like other constraints... i tried all constraints, everything is just fine exept with this one, and cone-twist is exactly what i need.... I join a simple file based on a SideFX sample scene turned into what i need... thanks by advance Cheers! Twist-Const-Restlength.hip
  22. FLIP - Hold tip of a snot?

    Hey guys, I'm working on this snot simulation and I need the top part of it to be "attached" to a nose. Any ideas on how to proceed? EDIT: Right now it's like this but I need to "constraint" it to a character. Thank's Alvaro Snot - v1-a.hipnc
  23. Hi, I’ve been approximating a hair simulation using wires (placed manually as NURBs curves), the idea is that I would constrain them to imported alembic skinned animated geometry and then export the result back to Maya. However, I’m having issues constraining the wires to the geometry. I’ve tried using an sbdconstraint and wireglueconstraint, but neither of these have any effect. The ideal solution would be the ability to simply constrain the roots of the wires to the closest point on the surface at bind time and then stick there regardless of where the alembic geometry ends up, as extracting the proper xforms for the head movement is another issue I’ve ran into so far. Any advice is helpful, Thanks, Sophie
  24. Constraints and animated geo

    Hi everyone, I was playing around with animated geometry and I encountered the following issue. I created this simple scene to show the problem I was getting with two ground planes, one of them is animated and on top of them I have a few boxes connected with a constraint to each other. The ground planes have a constraint to the objects touching them. I want the constraint of the boxes (red constraint) to start breaking when the ground plane moves. Right now I’m getting a weird behavior, where the constraint connecting the ground and the boxes is expanding (yellow constraint). When I remove the constraint connecting the boxes (red constraint), it seems to work fine but of course the boxes have not constraint and thats not exactly what I want. Here are two flipbooks and the hip file. Any help will be appreciated. rip_apart_constraint_01.hipnc constraint_issue_a.mov constraint_issue_b.mov
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