Jump to content

Search the Community

Showing results for tags 'dop'.

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 156 results

  1. Animated Pyro to Sop to Grain

    Hello Okay; Im starting with a sop with animated noise and transform, extract the velocity, which feeds my Pyro dop. After im using point deform on the result to output an animated poly sop model from the pyro sim. I was curious to add interaction FX using Grain with the resulting source. To have my pop source not static in my DOP, the only way I found was to have an impulse activation like $$F and a life expectancy very low (like 0.02, itùs in sec...). I have a few collision obj and forces. If i use a static activation like $$F=0, the sim reacts nicely and my object splash and roll, spread off on the floor and collide with objects like i expect. With small life, the particles dont reacts to the gravity, force and so. Which it's logic Afterall they are dying and being regenerated every time from the source position.// Maybe Grain is done designed for animated objects, or did i miss something? Thanks for your input, stay safe vincent* ________________________________________________________________ Vincent Thomas (VFX and Art since 1998) Senior Env artist & Lighting & MattePainter & Creative Concepts http://fr.linkedin.com/in/vincentthomas https://www.imdb.com/name/nm085962
  2. Hello, fairly new to Houdini here, I am having problems with a simulation. It should be fairly simple. I am simulating a animated object that is coated by a fractured RBD object and fracturing the object by using a SOP solver by Group Create with Bouding Objects and Attribute Wrangle with 'i@active = 1;' This simulates fine, except the Animated Static Object becomes active when a bounding object covers it and is triggered and starts to wobble around inside the half fractured coating. Is it possible to keep this Animated Static object from being activated? Any help would be appreciated.
  3. https://i.imgur.com/FsowZvp.mp4 Take a look at the above example. I'm transferring the Vellum i@stopped attribute to some cloth that is covering an object. I'm using a flat grid that animates top down over the surface while transferring the attributes. My issue is the i@stopped attribute is turning off again as the pieces of cloth fall away, outside the range of the attribute transfer. Is there a way for me to transfer the attributes and have them stay on the Vellum cloth once they've been transferred, no matter where they float away to in the scene? File attached (apologies it's 9mb - The statue geo is frozen in the scene). Fabric_Tear_v01_temp.hipnc
  4. dopimport y=0 is not y=0

    wired: working on a big destruction file. And always got another result as I assume. So made this tiny file to check the similiar steps one after another and found following: After importing the small cube with y and ty = 0 into dops it isnt 0 anymore. Only after 50 frames it level near 0. But not 0. only with a checked "compute mass" and density NOT 0, y=0. As soon as I change the density, the y component change. Why is this? Looks like the atoms have come to rest... ;-). But seriously, is this wanted, an if so, why? gluetest_2_objects.hip
  5. The documentation is very unclear. In the vellum constraint DOP, it says that I can use the activation parameter to update constraints at a certain frame. When I set the creation frame parameter and activation parameter to the frame where I want my constraints to be updated, nothing happens. The only way I can get my constraints to update is if I set the "update constraints" parameter to "every frame", but I dont want my constraints to be updated every frame, I only want it updated once!
  6. Hey there! I'm quite new in Houdini. I do not really like to ask questions, I rather tend to find answers by myself. But sometimes I hit the wall. This is the case I need your help guys. Im trying to make RBD sim in DOP NET with the simple spheres. My goal is to have variable scale and color of a sphere according to the noise. I manage to get color with POINT VOP in SOP SOLVER with MULTI SOLVER. But I stuck with the scale of a spheres. They inherit pscale from a GEO level. I would like to use pscale in DOP NET and manipulate it with the POINT VOP. Any ideas how to achieve it? I tried to make it with the particles, like in this tutorial https://www.youtube.com/watch?v=qXoSEnh94YQ&t=246s But particles tend to move erratically and not act like proper RBD. Balls on plane.hipnc
  7. Hi everyone, In the case of an RBD simulation with constraints, is it possible with a sop solver to copy or transfer the constraint attributes and broken group (which comes from the relationship_geometry Object Merge node) to the dop geometry? Basically I would like to use these attribs (angle, distance, torque, etc.) and broken group after the dop import, but I can't really get them. Do you have any idea?
  8. What is the best workflow for adding particles / liquids to a flat tank simulation setup. Think of barrel that is spilled or a hose that is pumping new liquid into a flat tank simulation. I somehow figured out how to add some volume velocity into my tank but can't quite understand how to create or spawn new particles into it. Being a beginner I would appreciate a thorough explanation. Thank you.
  9. How to add color gradient through velocity plus collision to influence color velocity? to influence the color such as this one here: https://vimeo.com/59024762 how did he do, but he used xsi softimage. if possible to make a Houdini?
  10. Hi everyone! I'm currently going through the Procedural Cities in Houdini Tutorial from Pluralsight. So far everything worked out great. I had to adjust some nodes (As the tutorial was made in Houdini 15) But it's working. I'm now in the process of aligning bounding boxes of Buildings to the geometry surrounding them (e.g. rotating the buildings so they face the streets) Using a bulletsolver and popattract. In the tutorial video this simulation runs smoothly... when I'm opening the exercise files on my Computer it runs fine too. But with my own file the viewport runs slow (like 1 frame every second) The perfomance monitor shows this: (The dopimport took even more time but I bypassed it here to see if the problem was somewhere else) I'm not sure where to check for the __DopDetailLook_Guide or how to influence it. But it seems to be viewpoert related, as entering a framenumber in the timeline simulates super quick and gives the right result... So this isn't really breaking anything as I can get the correct result anyways without waiting forever, still I would love to know why the simulation runs so poorly in the viewport. If anyone wants to see the hipnc file I'm happy to upload it somewhere. Any help would be greatly appreciated! Cheers! Daniel
  11. Hello, I'd like to perform matrix multiplication between 2 of 3x3 matrices(not coefficient-wise) and outer product between 2 vectors using HDK. So I'd like to know if the * operator supports matrix multiplication and outer product of vectors as in the example code below. UT_Matrix3 A = ... UT_Matrix3 B = ... UT_Matrix3 C = A * B // matrix multiplication UT_Vector3 u = ... UT_Vector3 v = ... UT_Matrix3 X = u * v // outer product If not, is there a function/operator to do matrix multiplication and outer product? Thank you.
  12. Hello, I'm trying to write a microsolver that changes the scalarfield's voxel value according to the points position of the given geometry. So, I'd like to know how to access the voxel data of SIM_ScalarField by index vector without iterating entire field. For example, changing the voxel value in [2, 10, 6] to 1. Thank you.
  13. Hello there I was looking for a solution on how to simulate two smoke objects with different density fields and still have them interact. I couldn't find a solution from a quick search so I thought I'd post here now it's resolved. To achieve this result you need to dive inside each smoke object and disconnect the velocity field. Copy the velocity field creation dop from within an object and attach it with an apply data beneath the merge where you bring the objects together. Set the data sharing parameter on this node to "Share Data In One Timestep" and you should be good to go. You could also share more fields between smoke objects if you don't require individual data for both I've attached a hip file All the best, Lucy multiObjectInteraction.hipnc
  14. Vellum + other simulation (rbd)

    Hi all, I am trying to figure out a way to let a vellum simulation interact with other simulations. In this case I want the vellum donut to collide with the chain simulation I made. My thinking was to do this through a dop import field. However there is no collision between the 2 simulations. Does anybody know how to achieve this interaction? Cheers! Chain+vellum.hiplc
  15. Hey guys, I need to create an effect like those in the reference images. I've started with a pyro sim with a high velocity on one axis to push it in that direct and then I'm adding noise to it as it slows down. I'm then adverting particles through the vel field however I am struggling to get the pro sim to expand like a cone shape like those in the images If anyone has any suggestions that would b fab Cheers
  16. Teleportation effect

    Hi, I recently finished this little teleportation effect. Some of it's based off of "applied houdini particles VI", but converted into 3d behavior. CC is always welcome:)
  17. hello guys! I have a pop sim that runs for like 30 frames as they fall .. then I want to revert(attract?!) them back to their initial position (as they were before falling)... I tried the per point attract on the attract node.. and I get their positions back .. how can I get their orientation also to be targeted to the initial orientation?
  18. Cloth DOPs

    Hi. I was digging in SideFX DOPs documentation and noticed such nodes as Cloth Mass Properties, Cloth Material, Cloth Material Behavior, Cloth Plasticity Properties and other cloth related nodes that seem to be missing in Houdini 18. Are they legacy nodes I don't have to care about or have I misunderstood something?
  19. Compensate DOP Scale Time

    Hello, Is there a way to slow down DOP particle simulation without changing liquid behavior too drastically? I made a liquid simulation with popfluid it looks exactly like I need but I need to slow it down to make it look like it was shot on Phantom camera (think of one of those fancy table tops from Marmalade as a reference:). I use standard 24 FPS and Time Scale on DOP is 1 substeps = 1, time scales on popfluid and popsolver inside DOP are 1 as well substeps on popsolver 1, 2. So to slow everything down I tried to half Time Scale on DOP but liquid behavior changed completely, when I try to do the same with time scales on solvers inside same thing is happening. So the question is is it possible to preserve liquid motion after changing time scale? Maybe unlock solvers, dive inside and change something there? Thanks. PS. i know that retime is other option probably most obvious, but unfortunately it doesn't look the way I need especially with collisions.
  20. Flip Fuid Volume Loss

    Greetings, I'm doing a basic flip simulation where I fill a cup with liquid and then I rotate the cup to spill the liquid into another cup. Sounds super easy and basic, but after some time fine-tuning the collisions and the liquid I can say with certainty that my liquid volume is getting less and less like my particles are dying or sucked into the geometry. A searched a lot for a solution, like changing the Scale of the scene, or lowering the Grid-Scale ( CG Wiki ), or change the collisions but nothing really helps at all. thank you in regards
  21. Hi; In a DOP network like image below, how can I import point velocity attribute, into DOP net? Thanks for helping. DOP_Velocity.hip
  22. Hello fellow magicians, I'm trying to better understand gasequalizevolume DOP inside FLIP Fluids and so far I haven't found anything usefull outside of the Houdini documentation and example files. So I tried to create a simple example file to test it out. So far, I can't seem to create one of the necessary fields for gasequalizevolume to properly work, the goal field. I used a gasmatchfield DOP and imported a pre-created fog vdb with the name goal, and nothing happened. To debug I setup a multifieldvisualization DOP and set the density field to goal, but it doesn't display anything... If some one could have a look at the file and point what I'm doing wrong... Also, if you any information or tutorials on this subject I'd be very gratefull! Thank you Gas_Equalize_Volume_RnD.hip EDIT: The Gasequalizevolume was wired in the wrong input. It needs to be wired into the volume velocity. Still can't get the gasmatchfield to work though...
  23. Thin Sheet Fluid

    Hey everyone, so after my very long thread (https://forums.odforce.net/topic/44053-implement-kernel-maths-in-vex/) I finally found a solution. The setup works great at 0.05 res, you might have to dive inside the solver and change some parameters to get it work at other resolutions (especially to get the droplets). Here are some test : Emission threshold at 60 (depending on the situation, there might be some abusive expansion, like at the end on the rubber toy, but this seems impossible to fix when you want a full thin sheet) Stretch threshold at 0.75 / Surface Tension 0.5 Emission threshold at 15 / Stretch threshold at 1.25 / Surface Tension 1 Houdini default Flip with Surface Tension at 1 Crown test with 50 Emission threshold (problem with infinite expansion with liquid dropping from the collider) If someone has suggestion to improve it, feel free to tell me I'm still working on fixing the infinite expansion issue, but the emission threshold is doing great until 20-30 depending on the situation Cheers, thin_sheet_solver.hipnc
  24. please watch this video : https://vimeo.com/172598946
  25. DOP to POP

    Hi guys! Just looking for a little bit of help, to see if what I am trying to achieve is actually possible and if it is maybe someone could assist me in figuring it out! I have attached my file below, I am attempting to make a Volcano react. This is the reference I am trying to copy to the best of my limited abilities! https://www.youtube.com/watch?v=9Plj4b79cwg My question is in regards to the node named SIMULATION, ignore the first DOP for the first smoke. I am working on the out put from the lava, now everything looks horrible, but I am trying to get the set up to work so I can edit things all at the same time (Uni assignment, short time frame, was recommended to do it this way.) Anyways I have the 'Lava' moving kind of how I would like for now and I now want to take the movement of the lava and turn it into particles to put into a POP to create small particles/sparks. I am certain this could be done. But I cannot wrap my head around how to achieve it, I got it done for the secondary smoke from the lava plugging the output into a pyro, which I haven't edited yet so that reaction is a bit of a mess. But I want to figure this out before moving on! Any help or recommendations would be hugely helpful! Or even if you know of any tutorials that walk through this? As I haven't come across any.... Thanks! Assign07e2.hipnc