Jump to content

Search the Community

Showing results for tags 'solver'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • General
    • Lounge/General chat
    • Education
    • Jobs
    • Marketplace
  • Houdini
    • General Houdini Questions
    • Effects
    • Modeling
    • Animation & Rigging
    • Lighting & Rendering
    • Compositing
    • Games
    • Tools (HDA's etc.)
  • Coders Corner
    • HDK : Houdini Development Kit
    • Scripting
    • Shaders
  • Art and Challenges
    • Finished Work
    • Work in Progress
    • VFX Challenge
    • Effects Challenge Archive
  • Systems and Other Applications
    • Other 3d Packages
    • Operating Systems
    • Hardware
    • Pipeline
  • od|force
    • Feedback, Suggestions, Bugs

Found 147 results

  1. Hello, I am triggering animation using a mask attribute, converting the mask to a group, and using a copy stamp to offset when animation is triggered. Using this workflow here by the awesome Matt Estela: https://www.sidefx.com/forum/topic/42799/ Everything works and seems great. What I am wondering, is if theres is a more up to date away of going about this that doesn't involve a copy stamp? Or doesn't involve converting my mask to a group? Ive attached a hip for anyone interested. Thanks you bunch of brainiacs! Trigger_Anim_mask.hiplc
  2. i have an initial selection of primitives that i append to over time. How can i track the birth and age of the newly added primitives in the group? i m stuck in the birth-age problem, but i have managed to isolate the newly added prims to the existing group. add_to_group_and_track_age.hip
  3. I'm building a simple solver for vine growth. Points created by the solver are then connected using an Add SOP via some id attribute. On each frame I want to pick some random points and spawn new ones with unique ids moving in different direction to form branches. Whats the best way to do it?
  4. Hey, bit of a specific use case here, but has anyone successfully used the .asCode() Python function with the SOP solver? I can't seem to get it to save and recreate the nodes inside of the sop level solver node. I spent some time researching it but haven't found anyone even mentioning this problem. Everything else seems to work fine with the function even the DOP level SOP solver. It's just the SOP level solver that has this issue. I'm kind of at my wit's end trying to figure this out. I might be missing something super simple or obvious here, but I'm hoping someone else has encountered this and figured out what is happening. I suppose it could also be a bug, I haven't taken the time to dig through all the change logs on the SideFX website. I'm currently encountering this in Houdini 18.0.348 (which has known issues with the .asCode() function) as well 18.0.597 (where those issues have supposedly been resolved). If anyone has any insight I'd really appreciate a nudge in the right direction. Cheers, Brandon
  5. Hey Houdini Users ! I am currently making a wetmap for my shot and I am having issue with the stepping when using the solver SOP. I tried increasing the substeps and also putting a Timeblend+Timeshift to interpolate between frames but neither of them seems to be working. If anyone know how to clear out this stepping and have a smooth trail for the wetmap please enlighten me Attached are the files, one is gif and other is mov. Wetmap_v001.mov
  6. Houdinified Acrylic Paintings

    Hey peoples! I recently started a personal project with the main purpose to explore setups that I either couldn't do during real production, curiosity or pure fun. As a base and also source of inspiration I'm taking real acrylic artworks of a good friend of mine. The photographs of the real artworks are prepped in Photoshop to be able to extract certain textures which I then use in Houdini to create my setups with. The concrete room was built out of a couple of individual decals and assets from Quixel. The whole thing is then being rendered with Redshift, comped with Natron and finalized in Davinci Resolve. From time to time it's seriously fun to play around with setups without having somebody behind me telling me what to do creatively like in a professional environment. No pressure, just fun Here's the first couple of clips I created in this series. Hopefully it's as fun to watch for you as it was creating it for me! You can also check it out on Instagram, Behance or Vimeo. Feedback, questions or whatever appreciated! Volume 1: Volume 2: Volume 3: Cheers!
  7. Hi. Im trying to make a growth setup. The simulation is too fast for me. I try to increase the FPS but didnt work. I also try the Retime sop but didnt work too. How can i make slower version a Solver Sop simulation? Thanks. 002.hip
  8. Hi, So I am thinking about creating the velocity in node geo1 and move the points in node geo2. The problem is, I want to change the velocity each frame so i have a solver node in geo1. let's call it solver1. when i want to move points in geo2, i created another solver node, solver2. I am thinking about simply reading the velocity in solver1 and use it in solver2, like using getattrib. However, I am not sure at each time frame what is the order of execution. How can I ensure that at each time frame solver1 is executed before solver2? Thanks!
  9. Hi I have a basic scene in which I have animated the rest length of vellum objects using a SOP solver. I then switch from the wrangle back to the 'dop geometry' at a certain frame. What I would really like to do is switch to the 'dop_geometry' when the restlength reaches a certain length. However I'm not sure how to reference this in an expression on the switch. Any help would be very much appreciated. Thanks Restlength_Switch.hipl
  10. Hey guys, I have a solver with a simple infection vex code that spreads the source for a pyro sim across a logo. The log later breaks apart, and is an imported alembic file. I can't figure out how to get the solver to update the alembics' animation each frame so that the fire will follow the parts that break off of the logo. I'm new to Houdini, and did a good amount of research, it looks like I need to tell the Prev_Frame node to look at an import of each frames deformations, I can't figure out how to do that however. Project attached, any help is appreciated, thanks! Fire_Sim_v006.hip
  11. I am simulating a beer overflow and somehow I can't get all the particles to slide down the collision geometry, which creates artifacts when meshing the simulation. Friction is set to 0 for both the flip object and staticObject (not animated), stickOnCollision on the flipSolver/volumeMotion is off and I have also set collision detection to none under the flipSolver/ParticleMotion Any ideas of what to try? Thank you (All the blue particles on the side of the pint don't move much towards the end of the sim)
  12. I have a solver (inside a genetic algorithm) that makes changes to a grid image at each step based on an analysis of the previous step's image. At the end of the solver a final image is outputted. I'd like to be able to see the changing images at each solver step. At the moment I can only see the final image because the solver completes all its steps inside a single frame, ie. it steps at a fractional frame rate, whereas the viewport update occurs frame by frame. I've been wondering if I could use something like time shift, time warp or retime but I can't work out how. I've also wondered if I could somehow force a viewport update at a fractional frame rate from inside the solver. Any ideas about how I could display image changes inside a solver or is it not possible?
  13. Ripple solver issue

    Hello ppl. I'm trying to figure out an issue with my simple ripple solver setup. The grid over which i'm triggering ripples, seem to moving down the Y direction slowly throughout the simulation. What am i missing? Attached the scene. Thanks! Ripples.hipnc
  14. 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!!
  15. Hi guys' I would like to transfer some attributes from a fixed object to an animated one, using the Solver node but it seems that the Solver node doesn't accept animated geometries on its input, right? How can I fix it? Thanks for helping. AttributeTransfer_01.hip
  16. Rotation in Wirecaptures

    Hi, the wire capture and wire deform are not taking the rotation of the points to rotate the geometry, attaching the sample scene file below, Basically, I'm rotating the curve and deforming the geometry using wire capture and deformer but it's just moving leaving the rotation Thank You wirecapture rotation.hip
  17. Help in understanding Solver

    Hi everyone I'm kinda new to houdini and I've recently started playing with the Solver SOP, but I don't really understand how the geometry is processed inside the solver. Essentially if I try to move some points through a solver, what I see inside of it is a static mesh that moves its points but that doesn't really shifts (as if on every frame the points are set to 0 and then moved again) but if I look at the Geometry (one step above) viewport everything works as it should. Can also anyone help understand "dop import" node and how it works in the solver. Any help is appreciated. test_solver.hipnc
  18. Pyro and RBD interaction

    Hello, this may be very simple question, but I have struggled to find anything about the topic on my own. I am wondering how would you get pyro interact mutually with RBD packed simulation. Or what is the workflow for let's say explosion from the side of the building, when I want the explosion to be the force by which the building is being broken. I'd be super glad for any pointers or help. Thanks, Clear
  19. Hi, Is this the way to add a SOP Solver in the new RBD Bullet Solver SOP? I noticed that we have access to a lot of nodes inside it. It says "wire pop forces into here" but not sure how to hook up a SOP Solver. I'd like to set up some custom activation inside this RBD Bullet Solver SOP.
  20. Hey guys. am recently decide to use houdini as a 3D package and i have an issue in a rigid body simulation. The problem is: i have a chain ring that should drop on the floor and after dropping all ring chains should interact with each other. at this moment when i drop chain ring, all chain parts just dropSide Effects Houdini 2021.02.26 - Effects Houdini 2021.02.26 - Effects Houdini 2021.02.26 - Effects Houdini 2021.02.26 - and don't interact with each other, they interact only with floor is that possible to make all chain parts collision object? Side_Effects_Houdini_2021_02.26_-_00_22.09_02.mp4
  21. 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.
  22. Hello, I want to delete alembic cubes when collide box. But using solver to write attributes, The alembic couldn't move.. (I know the reason that is read looping for the first frame..) Anything way to avoid this? Thank you ToOdforce.7z
  23. Hello. I'm struggling with changing vector direction inside a solver. In the file attached there is a point that reads vector attribute of a nearpoint and uses it in order keep on moving. The movement is done in solver. The problem is that it can after doing a "step" the point can take a new vector that is opposite to it's current direction and "step back". It returns to previous position where it gets a former "go ahead" vector and does a "step forward" and repeats the whole vector change and "back and forth" movement on and on. Inside the solver I try to compare vectors of previous and current frame and build a condition - if they are opposite let the point go down {0,1,0}; But no matter how I try it doesn't work. If someone can help me... SOLVER_problem.hipnc
  24. Few nodes won't work on OpenCL

    Hello, I am trying to work with OpenCL but as soon I enable them on few nodes, like the gas disturb, gas turbulence, it stops working. I just get a mushroom smoke effect. Does openCL not work on these fields? I have attached some screenshots. The first image is without OpenCL, the second one is with smoke disturb disabled and the third image is with openCL enabled on Smoke disturb.
  25. 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