Welcome to od|forum

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.

Search the Community: Showing results for tags 'sop solver'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • General
    • Lounge/General chat
    • Education
    • Jobs
  • Houdini
    • General Houdini Questions
    • Effects
    • Modeling
    • Animation & Rigging
    • Lighting & Rendering
    • Compositing
    • Games
  • 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 14 results

  1. Hello OF, I have a small issue which I hope you can help with... I am creating attributes at SOP level to control the breaking of constraints in a SOP Solver in DOP's using the following VEX code in an attribute wrangle connected to 'relationship geometry' of the SOP solver. if (s@constraint_name == "pin_between"){ if ((f@torque>@break_torque||@angle>@break_angle||f@force>@break_force)){ s@constraint_name = "pin_broken"; i@breakframe = @Frame; } } My issue is that when I disable one of these attributes at the SOP level, the sop solver seems to interpret it at a value of 0, and the objects constraint will be completely removed on collision. Is there a better function to use than 'or' in this situation? An 'if else' seems more appropriate, but I am unsure of the syntax of that in this situation within VEX. Any help would be greatly appreciated. Many thanks in advance.
  2. hey guys i'm properly having my chuddies rubbed here. I've got a scene where i have a simple walk cycle character. I'm trying to get him to crumble away but for the life of me i cant get the bloody thing working!!! I've tried putting a colour on the character, then a group with a few red points. then i'm using a small wrangle code from a yt tutorial to 'infect' outwards from those red points. I've tried this in the sop context and in the sop solver within dops and its biting my ass big time now. I cant understand what i'm not doing right. in the same scene i'm also doing the same trick with a sop solver and a pointvop for noise/colour this works ok but the character moves 'through' the 3d noise and those grains fall away - but i cant suss out how to lock that 3d noise down so it moves with the character as opposed to him sliding through it :/ can anyone help here? I'm at my wits end with sop solvers - i've a feeling i'm close but its that final tweak just to get it to work thats eluding me I've included a scene with the two examples/fails and my walk cycle alembic for you cheers ant GrainWalk4_using_infect_wrangle.zip
  3. Hi guys, a friend was asking if he had some moving points and for example there's a group by bounding box, so some points enter the group for a few frames. Is there a way to delete those points from the entire sequence? I was wondering the same thing myself, so I gave it a go using a SOP Solver. Check out the example file. delete_red.hipnc
  4. I am trying to figure out how to spawn new wire geometry within DOPs as it simulates. I create the full wire shape at sop level and I then I animate the deletion of its points backwards, from a couple of points to the full set. Of course just by importing this changing geometry, the wiresolver won't re-import it on on every frame. I looked into combining a SOP solver and tried various approaches, but none worked so far. Deleting points in the sop solver didn't work. Then I tried deleting the primitive, adding or even copy (to aquire all the wire attributes) one point at a time and connecting them all with a new line primitive. But that didn't work either. Any ideas? thank you
  5. Hi, folks. I need to set up a simulation where dynamically-generated arrows fly, then collide with a deforming surface and stay stuck to that surface (shields carried by moving soldiers). Importantly, the arrows should NOT just align along the prim normal on collision; they should protrude at the angle at which they collided. This is a topic that's come up before, but I haven't been able to find a satisfactory answer about it. Some suggestions don't quite hit all the elements I need; some are for older versions of Houdini and so might not be as relevant/accurate (I'm on H14). The approaches I've considered are: 1. Particle-based arrows that stick. It's easy enough to copy arrow geo onto a particle sim, and have the particles stick to the collisions surface. However, then the particles have to start inheriting the orientation of the collision prim as it continues to move. This could be handled two ways: The collision geo is deforming. In this case I'll somehow have to calculate how the collision prim has transformed from the moment of impact to the current time. The collision geo is transforming. In this case I'd use rivets to attach non-deforming stand-in geo to the moving collision objects (which don't change shape). Not ideal, but it might make it easier to work with the orientation values? 2. Particle-based arrows that create geo. Having already grown sick of the mathematical jungle of quaternions, matrices, and dihedrals, I wondered if a better approach might be to make each particle spawn some geo in the colliding object's network instead (presumably using a SOP Solver?) , then die. This would hopefully eliminate the need to continuously update orientation. 3. RBD-based arrows with constraints. Moving away from particles altogether, I wondered about using simple Bullet geo for the arrows, and dynamically creating constraints to pin them to the shields when they impact. An advantage of this method would be that it would allow realistic stick-like collisions and bounces for loose arrows--something particles can't really do. If anyone has any thoughts about which of these methods is most promising, or has any specific advice about how to implement them, I'd be extremely grateful to hear. Thanks in advance!
  6. I have a wireobject that is empty (has nothing in the SOP path) and I'm trying to add wires during the simulation using a sop solver. I'm enabling the solver on one frame (frame 10) and merging it with the current dop geo but they just seem to flash on for that single frame but don't seem to "join" the simulation.. I've tried adding certain attributes like mass, density, initialpid to try and initialise it but nothings working...
  7. I am new to the packed primative RBD in H14 and have found some examples of sops level activation, but how do i make an rbd packed primative active based on a hit or force value? For example a sphere hitting a cut up box suspended in the air? Here is a basic scene. I have attempted to use the sop solver but i just don't get it. Thanks.
  8. I am doing a RBD Fractured Solve. I want to use the Sop Solver through the Multi Solver to push and deform the objects to a final destination. I notice that when I transform the objects in the SOP Solver away from it's object center, it tends to do weird stuff. Like trying to still revolve around it's original pivot. Is there something I need to do to maintain a proper center pivot?
  9. I have some packed primitives all constrained together and I would then like to constraint them to an object that i've animated in sop. Is there a way of constraining my packed primitives to and RBD object so that I could enable 'Use deforming geometry'? Or am I able to update the translation and rotation of a packed primitive in DOPs (using a SOP solver or otherwise) - The geometry is not deforming is only translating and rotating. Thanks, Mike
  10. Hey everyone! While I'm trying to learn Houdini, I am starting to understand the mindset, but still I keep stumbling over technical difficulties. This is a very simple scene: 1. I emit points from a box in the air 2. The points land and hit a ground box and get in the 'snowflake' group. 3. I am trying to use a SOP solver to copy a metaball on the snowflake group points, but the points just disappear and nothing happens. 4. I am also trying to achieve that whenever a point falls and lands and then makes a metaball, the other points can now fall on this metaball and create new metaballs from there, thus making a piling up / accumulating effect, like layering snow or wax. Thanks! Snow_001.hip
  11. Hi! I'm trying to recreate something like the duplicating treasure from Harry Potter. I've got a pretty good start but i've run in to a couple of problems. Each generating more problems. The first is that I haven't succeeded to constrain my duplicating effect to only solve once a frame for each object. And the other, more important, I haven't managed to successfully give my duplicated DOP objects unique names. It works for the first couple of duplications but after a while it all falls apart, this leading to incorrect velocity etc. I'm using packed objects in combination with a object_merge in a foreach sop in a sopsolver for this, an area that I'm not at all comfortable (DOPs). If someone wanted to take a look I'm grateful. And / Or if someone is trying to do something similar, I think I'm up to a decent start here. (Could be wrong) Thanks / John Duplicating_Test_V01_02.hipnc
  12. I wanted to create an effect where an attribute could be transferred and then spread throughout the object - I found the scene on this page which worked great: http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=28148&view=next&sid=1030caf41e7f90f948b8db61b7222608 However I need to do the same sort of thing inside DOPs - I want to have some highly viscous fluid and melt it with another object then have the heat (or lower viscosity) spread from the point of contact. I've tried using a solver sop inside of a sop solver (connected to the particle motion of the flip solver) however this doesn't seem to work as the solver is using the previous frame so the simulation can never progress (I think thats whats going on). So I basically need to transfer my custom attribute before the pre-flip-solve. Is there a way to do this? I've attached a scene file with my current progress Thanks, Mike wax_melting_v02.hip
  13. Hi Guys I'm currently trying to deform a pre fractured object using a multisolver with an rbd solver input and sop solver (Dops). In the solver I have used a metaball with a copy to compute the impact radius and then plug that into a magnet sop. I was just wondering how I can get my geometry to stay dented, maybe rely on a threshold value and also after the impact, stop the sim from freaking out. If anyone could please help i would really appreciate it. Thanks for looking at my post WORKON.hipnc
  14. I have been banging my head against a wall (with a static solver) for days now. I really cannot make this thing work. I hope someone can give me an insight of why is this not working cause my head kinda hurts. I have a sop solver inside a sop network. All the sop solver does, is the following: - move the input geometry off by a "stepsize" on the $TX - add a point and merge it with the previous geometry When I play the simulation I have a nice and clean series of points on the axis X, growing by one point every frame. That all works perfectly. Now, I add a timeshift with the number "100" in the "time" field. I expect to see 100 points in a line, on the X axis. And it works ! Now I change the parameter "timestep" (on the node "parameters" referenced in the sop solver) and I expect to see my line of points change interactively! But that doesn't work. The weird thing is that sometimes it works (like the first time I do it after playing the sim), and all the subsequent times I change the parameter only the first 'iteration' of the dop network gets executed. I attached a simple hip file to illustrate the issue. Any idea how to fix this ? Alessandro dopnetissue.hip