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Found 86 results

  1. How does Cache in sim works?

    Hi all, I've been doing some FX set ups with pyro and flips and I was wandering if anybody could explain me how not caching the simulations can affect said simulation. let's say that I have a whole set up where I bake the sims after compressing the volumes and simulating, and I want to sim Fire, Smoke, dust, etc on several layers. if I make a ROP network and save to disk from there, does not caching implies it has to resimulate all each time it has to simulate a frame? (I imagine not, but where does it store it then?), let's say I save all the files in the background, this way Houdini assigns a job without waiting for another to finish, If a job gets temporarily suspended, does it has to start from the first frame when it gets resumed, if not, where is the necesary information to resume stored?, is it on the saved .bgeo?, or maybe there is a specific workflow that is already stablished. any light shed into this would be greatly appreciated.
  2. Orient / Lookat for Bullet Objects?

    Hi, I'm hoping someone can help me as I've spent too long on trying to work this out by myself now. I'm doing a simulation with balloons and want to have them start in randomised orientation and then slowly resolve their orientation to have the wider bit at the top. This seems to be possible with POP spin for particles, but I can't work out how to do it with bullet. So far, I've tried altering the orientation manually in a wrangle in dops and trying to find a way of getting a vector into dops, such as with normals, to then be able to compare to an up vector and add in angular velocity until they match. Altering the orient attribute in DOPs seemed to do nothing if you target it directly, so perhaps it needs to be worked on the intrinsics?? Nothing I tried seemed to work, so I'd love to know if there's a way of achieving this, so would be grateful for any help. Many thanks! Toby
  3. Hi, I'm quite new to Houdini so, I'm probably doing something really wrong. When ever I go into my Dop network for my sim everything freezes up and it takes several minutes for any change to update, it's nearly impossible to work with. I've attached my scene File Thanks a lot Josh ImageBased_Destruction_Cobble_Test_002 .hipnc
  4. This is a bit fx, a bit modeling, a bit rendering, so I'm throwing it here-- I am running sims on a tree model. The original tree was too hi-res to simulate, so I had to run Clean and Remesh to reduce its poly count a little bit. It still proved too oddly-modeled to run a point deform on the original based on the sim, but the sim'd model is still high-poly enough so we're going to use it as the final. What I need to do is transfer the UVs, in world space, from the original model to the down-res'd sim'd model. I tried using Maya's Transfer Attributes, which does exactly what I need, but choked on the source model's size. How can I do this in Houdini? (I know there will be some changes, but those should be mostly in the little tiny branches that are okay to lose, and this is not a hero tree.) I assume it will be something like storing the original models' point positions and then somehow applying those points to the end result of the sim'd/cached model, at which point I could do a straight attribute transfer (and although I get this theory I don't know the steps required), or is there a better way (and if not, how would I do my suggested way)? Thanks so much!
  5. **I'm amending this--originally it was just the below question, about making POP particles collide with FLIP sims, but I just was toying with multiple POP emitters/particles in the same scene, and they don't seem to want to play together easier--so my more fundamental (surely stupider) question is: how does one make different particle systems (POP, FLIP) interact? For instance, in the supersimple screenshot, I would want the orange particles (which have initial velocity on x) to collide with the blue ones. I would think, since they're part of the same POP solver, this would just happen. I would think wrong.** I have a puddle of bood, a viscous FLIP fluid. I have POP particle rain (a la https://www.sidefx.com/tutorials/rain-systems-and-wetmaps/). How can I make the rain (the particles--I assume not the instanced geo) collide with/splash the FLIP fluids? I understand how to use POP forces on FLIP sims, but when I put a POPnet and FLIP sim in the same scene, they just ignore each other. Since static/RBD and particle (FLIP or POP) solvers all play so well together with minimal extra effort, I'm sure getting POP and FLIP sims to play together is something simple and dumb. Thanks!
  6. Can't select points in DOPnet

    I have a question that is so dumb that I can't find an answer in Google. I'm working with FEM objects. I need to select points in the DOPnet to make constraints. I can't select points, just objects. Thus: can't do pinning and stick things to things. I've done this a million times on my home computer, but I'm using a different one now (with H17 installed mere days ago), so I'm sure it's some big obvious setting. Thanks and duh.
  7. Radial force for FEM objects?

    So I'm sure this is a stupid, way-newbie question: I am working with various FEM elements. What I need is a radially-orienting force to "push" the objects. However, I want it to pulse, like a fan being turned on and off. (I couldn't get the fan force's shape to behave in such a way to make it completely spherically radial.) From my Googling, it looks like magnet force is the way to work, but it seems impossible to control. I've been scaling a metaball using a sine-wave based CHOPnet, but the metaball itself pulsing on a SOP level doesn't seem to impact the force's scale in a not-unruly way, and the force scale can (seemingly) only be keyed in steps (which is why I went for scaling a meatball). This step keyframing is a problem because I want the force to oscillate to negative values, too, for push and pull. There doesn't seem to be a way to scale it in general within a certain area--i.e. to have a super-strong force the field as a whole has to be enlarged, so one-half of a FEM object can't get pulled on very strongly while the "outside" half is unaffected. I'm used to working with Maya, so really all I want is a nice, tidy Radial field, which can suck and blow (radially) as I tell it. Any help is profoundly appreciated.
  8. Hi Does anyone know good tutorials for learning Explosions? Thx in Regards Balaji J
  9. When would you use FEM over Grain? The last couple of weeks I have been working with Grains, and got a good understanding of how it works. It seems that you can do pretty much everything with this tool in case of cloth and simulation of object that will deform. I haven't been using that much time on FEM, and from my perspective it looks like a tool that has a lot of overlaps with the grain tool. It could be nice to get an understanding of where the FEM and Grain tool differs and where to use which, from people that has good experience with both tools.
  10. DOP Wire solver - differents width

    Hi ! First post here, I'm starting Houdini since a few weeks only... I'm wondering how to set different width (for repulsion) for each wire I've created. I've tried to create a random point attribute to drive the width into the wire object but it doesn't seems to work, I feel missing something. Help needed Thanks RANDOM_WIRES_0.1.hip
  11. Hey guys. On my "life goals" list there is this insane task of creating a dynamic car rig that is fully customizable for different shapes and sizes of cars (normal road cars, 4x4, race cars, etc) It should be something like the videos below. The reason behind this is I love cars (obviously) and I want to create a ton of car related stuff in houdini to learn dynamics, pyro, flip, grains but I don't want to spend too much time with setting up a vehicle and meticulously keyframe animate every aspect of it. The videos below look very realistic in terms of physics and they look like they're ready to be lit and rendered, and all these extra elements to be added. Needless to say that my intention is to share the setup if it ever gets this good. So what do you think would be the best way to approach this complex task? Is there already something out there that can be used for this? Ps: in the meantime I'm already downloading every hip and hda that is even remotely related to this topic
  12. Ideas to achieve this effect

    Hi im learning houdini and a few days ago I found this and I really wanted to create something like it using Houdini, the problem is that I don't really found a way to do it and I'm kinda frustrated, my first idea was to scatter points on the base geometry and then copy to points a grid, but then I'm not sure if that could work or how to make a cloth sim for the grid which should be colliding with each other, idk maybe is easier that I think and im completely in the wrong path haha if someone can guide me a little bit on this little quest ill be beyond grateful. .
  13. combine flip objects

    Hey There, Hope this message finds you well. I'm after a bit of help in regards to flip fluid interaction, I want two different flip objects to be able to interact with each other, within the same solver. this is what i have already. I can achieve interaction by combing the points within the same flip object, but i need to bee able to mesh each flip object separably. any help would be most appreciated TEST_BUUBLE_02.hiplc
  14. Hello guys, I wanna make an ocean with an ice berg floating over it, I already added environment light, And checked all the diffusion values needed for it but still getting such 2D type of look in my render view i donno what to do now Here is screenshot of my file-
  15. Hey guys, I am new to houdini and i need to know how to project any image on grid in houdini?? I'm working on an ocean scene where i have to set the image of fish on grid over the ocean.
  16. Hey guys, i need to emit the same smoke trail even from the other part of the jet, I cached out my simulation but i just need the smoke trail and not the jet so that i can transform it onto the other part. Any idea how to cached out only the smoke trail from the simulation. Here is my file spaceship_01.hip
  17. Hey Guys i need some help actually i want to emit the same smoke trail exactly from the other side of the jet, Do i need to repeat each and every step again to emit the same smoke or is there any way to copy the same smoke trail. Am new to houdini so dn't know much stuff Here is the screenshot of my file -
  18. Well am new to houdini and trying this tut where i have to emit smoke from this jet but i don't know how to get rid of this sprite spacing I have tried to increase the number of particles and also adjusted the scale and ramp of the pop sprite but its giving me the same result. Here is Screenshot of my file -
  19. Hey guys Well am very much new to houdini and working on some mini destruction scene, The problem is i have turned both window and lamp to rbd packed objects so that it collides with the car. But the lamps are falling way too before when the car actually hits them, Kindly let me know the solution. here is my file - car project.hip
  20. Mesh Trail Clothlike Effect

    Hey fawkes! Any Ideas on hot to achieve something like this? Been thinking about using some emission group with a POP and some trails. My doubt is how to mesh the stuff and give it the subtle cloth dynamics. Maybe a Geometry or Point Vop with a noise. How about UVs here? Any Ideas? Cheers!
  21. Hi, ODfellows! This is my first post. I'm glad to in the company of experts. I'm hoping some kind soul can help stop my accelerating hair-loss. So... I'm trying to tie a basic shoelace style knot. I've made groups for the ends of my wire to make "aglets" (the bits on the end of shoelaces), but I'm having trouble guiding them around. Am I missing something obvious? Thanks! Slideshow Blob
  22. Inflate with SOP solver

    Hey all, I'm inflating spheres by using a cloth simulation and SOP solver to increase targetP by normal direction over time. That works great. My issue is, as the spheres inflate they don't react to the force of neighboring spheres pushing against them. You would expect as they push against each they move apart. Right now they act like they're balloons glued to a wall. Any tips for how I calculate the new inflation force to feed back in to the dynamics? Screenshots and .hip attached in case they're helpful to anyone. Thanks for any help! cloth_sop_inflate_01.hiplc
  23. Hi all, i hope you are wall well. I have a quick question regarding exporting of transform data from my rbd object. I need to use the transforms in Maya. So i have tried to export the rbd as an fbx, however i still do not get the individual transforms for each peace in my rbd sim. So as an example imagine a sphere attached with cubes. I would want to export the cubes and each other their transforms from Houdini to Maya. any one have any solutions? Thank you
  24. Intersecting geometry fix

    Hi guys, I hope you are all well. Okay, I have this issue for this personal project I am doing for a friend's short film. Basically, we have a rigged animated model of a man walking. I need to attach these cubes to the body (all over the body that is) completely covering his body with cubes. I then need the cubes to be colliding with each (basically to have no intersections between the cubes). Can someone please give me some advice as to how I will stop the intersecting geometry. I have scattered points on the animation, copy to points the cubes and have run a rbd solver to solve the penetration but I still do get some intersecting. I am sure there is another way for this. Thank you all soo much. Merry Christmas
  25. Probably a very noob question... but what are the differences and benefits of the two ? They both run a simulation over a SOP network... are they any different in what they can achieve ? Thanks! J
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