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Found 113 results

  1. Hello, I am studying muscle system, and prepared a setup with a cycle inplace walk animation for my creature. That way, everyhting worked fine. Next step i tried switching the old animation with a new one, running in space, much faster than before. The result now appears completely broken, seems like muscles cannot follow the bones promptly, they're remaining behind the bones and intersecting each other they are not able to deintersect. I just tried to: • increase the stiffness for muscle-to-bones and muscle-to-muscle constraints, in Properties Sop • remove all damping values, in Properties Sop • increase substep, in Solver • increase constraint iterations, in Solver • added velocity stiffness factor (fresh new property in 19.5.409), in Properties Sop • added velocity blend, in Properties Sop • enabled velocity blending, in Solver • increased velocity damping, in Solver None of them worked or gave acceptable results. Any tips on how can i fix it? Thanks Update: speeding the solver x2 faster seems to give better results, although still not perfect. Not sure this is the right path anyway.
  2. Hello. I watched this tutorial video and created a spring simulation. Next to that I want to give Collision to the spring constraints so that they collide with other objects. Do you know of any way to do this?
  3. Hey all I have question regarding a pretty simple DOPs setup that I just can't seem to get my head around... Basically I'm simulating soil and turf being torn up. I'm using Grains for the soil and Cloth for the turf. I'm happy with both material properties now. The issue i'm facing is bonding the two different objects... I know it should be easy but whatever I do, it seems as though the objects remain pinned to their start frame once constrained to one another in a DOP Net, resulting in odd "hanging" behaviour, where only the grains fall and leave the turf behind or vice/versa What I'm aiming for is two-way coupling of the turf (cloth) and soil (grains) sims I've attached a couple of images to demo my setup - as you can see, there's vellum constraints node set to “Attach to Geometry” the constraints node is referencing the Geometry SOP group “Grass” and Target SOP “Soil_Geo” + SOP Group “Soil” When looking at the constraints, after a while of playback, they appear pinned to an static “start frame”, rather than continuously updating geometry I know i'm super close to cracking it his but I just don’t know what small thing it is that I’m overlooking
  4. Hi ! I'm currently struggling on breaking constraints. I want my constraints to break if their length is higher than a given threshold. These constraints has to be soft constraints and I have to keep them animated (it's for my work). I tried to break them in the SOP Solver connected to the constraintNetwork, but for a reason it doesn't work at all. I've created hip file to show the problem more clearly. If you dive into the SOP Solver node you'll see that, long constraints get detected, but it doesn't affect the simulation. Break_Animated_Cst.hipnc
  5. Hello, I'm using Vellum Source to emit multiple spheres over time and I want to increase the Rest Length Scale of each individual sphere every frame, starting at 1 (for each piece) and incrementing. Realized I have no idea how to select individual bits of sourced geo within DOPs and can't seem to find it anywhere online. Thank you!!
  6. In the attached scene I'm emiting vellum softbodies and I'm trying to create some stitch constraints dynamically (based on a distance threshold). For some mysterious reason it is not working and I can't really figure out why... vellum_emit_softbodies.hipnc
  7. Animating a Spring Constraint

    I'm trying to get these two objects to move towards each other after they hit the ground. Blend solvers are being used to allow the objects to transition between their keyframed positions and dynamic states and I need to add an attractive force which is what the spring constraint is supposed to be for. If I plug it in and doing nothing to it outside of hooking up the constrained object and the goal object it works fine. However, I want to control the timing of it so it can work it into an animation. When I tried to keyframe the spring strength or activation parameters the constraint would stop working or not work properly. Result from keyframing the activation parameter. The objects do not pull towards each other, the constraint just keeps them in place. Node network Does anyone know why this is happening? Thanks in advance!
  8. Hi all, I've got a motion editing setup happening, but it gets really slow heavy at certain nodes. I was wondering if anyone here could have a look and point out any efficiency gains I could be making? I've been figuring out a workflow for doing motion editing (animation) of my mocap that gets transferred to a metahuman. (Because of issues I was having with Houdini'd retargetting, I ended up doing the basic retargetting in Maya. But I'm doing the motion editing in Houdini) It's all working well - Thanks to madebygeoff for getting me started - I have all the basics in there; fingers and posture correction. I've also got a constraint setup for locking/controlling the right hand. But when I start using it - by turning the blend from 0% - 100%, my framerate drops a great deal - The arm constraint is very heavy when I do use it. Hoping someone here could have a look and make a suggestion or two. I've attached my hip file, plus an example fbx to plug in to the top. 'cheers, Sim MotionEditing_TEST.hip seq_01_t3_Sup.fbx
  9. Vellum Sand breaking

    Hi all,I am making a ground breaking effect in which a stone comes out of the ground and making primary debris and all.The condition is I also required to bring soil and ground dirt during eruptions I have managed to use the vellum grains to solve this, along I have used the "attach to geometry" constraints to make the vellum grains stick to the broken pieces. But now I also want during the collapse and hit on ground once the pieces fall on ground and make an impact ,some amount of dirt should also left on floor due to the impact. I can do this while playing with the breaking threshold but its not on per Debri I want to customize it so only some pieces would leave dirt rest not all. If anybody wants a file I can share too.
  10. Vellum Sand breaking

    Hi all,I am making a ground breaking effect in which a stone comes out of the ground and making primary debris and all.The condition is I also required to bring soil and ground dirt during eruptions I have managed to use the vellum grains to solve this, along I have used the "attach to geometry" constraints to make the vellum grains stick to the broken pieces. But now I also want during the collapse and hit on ground once the pieces fall on ground and make an impact ,some amount of dirt should also left on floor due to the impact. I can do this while playing with the breaking threshold but its not on per Debri I want to customize it so only some pieces would leave dirt rest not all. If anybody wants a file I can share too.
  11. Hey all, trying to have constraints attach to geo in vellum to follow a sphere, all works, but then tried to rivet it to a moving character and vellum sees the sphere at 0,0,0, not where its riveted. Cheers!
  12. I would like to delete vellum grains and their constraints so that I can pump more grains into the scene. This is something I've been struggling with for quite a while and all the tutorials I found do not seem to deal with constraints when deleting grains. I've simplified my setup to its bare minimum in the attached file. Any advice or relevant link would be much appreciated. Grain_Constraint_Delete.hip
  13. Delete Vellum Particles with constraints

    Hey Guys. I was wondering if there is a way to delete particles in a Vellum simulations when they have had constraints? The scenario I have setup the particles have constraints, then I remove the constraints based on a condition, and when I try to remove the particle as well it craps out on me. Attached is a simple example file to showcase the issue.DeleteVellumParticlesWithConstraints.hiplc Thanks
  14. Hi, I have a fractured simulated object that is colliding with other object and I want to make some of the pieces to stick to the collider for rest of the simulation. I am not sure if I should do it with constraints or if there is any other way. I found this example video which is pretty much what I am looking for - Sticky RBD sim. I will be really grateful for any advice or example file. Thank you.
  15. Why Bullet sucks at Car rig?

    Why difficult to the constraint when using Bullet Solver. I tested in C4D's Bullet Solver. it was superfast to rig dynamic car. The result was Impressive. In Houdini, Standart RBD Solver was easy to constraint. In my mind, I want to Crash many cars in my scene only use a bullet solver. Any Pro guys, Can you do in Houdini? Thank you. Here is how I ***** up the scene. Car_Crash_v001.hip
  16. RBD multi fracture

    Hi guys, I'm unfortunately pretty bad with RBDs. I'm wondering how you could quickly setup a two step fracture. Like having big chunks and the inidividual polygons of those chumks should be glued together again. Does anyone have a quick initial setup to show? Thanks in advance!
  17. How to use RBD constraints in DOP?

    I wonder how to import RBD constraint SOPs inside DOPNetwork ? for example RBD constraint line.
  18. Hello Everyone, I am currently struggling with a personal project. I was trying to figure out metal deformations in Houdini using Bullet solver and constraint switching (switching back and forth between glue constraint and soft constraints). But I am not satisfied with the results of the simulation. Is there any way to blend custom animation to guide the entire object in a specific way while allowing for deformations to take place? A perfect example would be a car hitting an object and continuing along its path with deformations. I've tried a lot of techniques without any real success. So far the closest I was able to achieve was using a pop wrangle to get position data from a SOP path, calculating the difference using the current position in the simulation and the position from the SOP path and then adding it as velocity. It works somewhat like an active guide, but the simulation always lags behind the animation or the velocity keeps escalating out of control. Could really use some fresh ideas. Thank you in advance.
  19. Hi, I made some RBDs some are broken via RBD Material fracture and some I broke with boolean fracture. All have constraints and it looks good (picture a), but when I use a RBD constraints from Rules node the constraints looks crazy (picture b). So the animation looks like the parts are not really free and the broken parts are not flying away but hangs around the area as they would be bound to something. I think it is the matter of constraints. Can anybody give me a hint how to solve this problem? Thanks a lot! D.
  20. Hello masters! I know this probably is a noob question, but my guide geometry for a fractured geo all appear to point to a distant pivot point, probably a modeling mistake i did... Is there a way to correct this easily, or i would be better off re-modeling my initial geo ? Thanks for any help !
  21. 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!!
  22. 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.
  23. 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
  24. updating vellum constraints dynamically

    Hey all! I was hoping to get some help figuring out a way to update the stiffness value of a vellum constraint geometry across the frames of its simulation. I can write an attribute wrangle like the one pictured and it will update the starting frame and the simulation bakes from there and plays as though the values werent changing at all, much less becoming negative. I tried dropping into the vellum solver and seeing if I could figure out anything in there but nothing seemed to work. Im still pretty new to houdini so I expect it to take some time but I was hoping to eventually take whats done in these two awesome videos and merge them into a project where a genetic algorithm produces tensegrities that update their stiffness over simulated time in order to deform in ways that cause them to (hopefully) roll towards a target. Hip file of the simplest version of the problem is attached in case it helps! Thanks for reading!!! VellumConstraintsHelp.hipnc
  25. Hi, I'm quiet new in this big world of Houdini, i need help. The project consists of creating spheres on the points extracted from a pop simulation and then destroying them. The problem I encounter is that when I put the glue on different spheres it seems that it creates the glue on all the broken pieces. It could be the fact that in the assemble node, it considers those points as a single geometry, but I don't know how to divide those points as unique entities and then apply the glue only on the individual spheres and not on all of them as a single object. Thank you in advance for your attention and any help. I attach the file below. Thanks a lot! Fra_pop_copysphere_and_rbd_.hipnc
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