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 'cache'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • 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 34 results

  1. Hey Guys, I am pretty new to Houdini so excuse the noob question. I did a pyro sim and saved it for 120 frames as .sim cache. Client asked for extra frames so i came back and simulated extra 100 frames. When I render I get the proper render for the original 120 frames but for the remaining 100 frames I have a frozen frame at F120. In my cache files I can see the size changing so it seems like the sim went all the way, but in the view port I cant see it (It is frozen after frame 120) and in the render it only renders upto 120 and then frozen frames. I tried re simulating the whole sim for the entire 220 frames but it sill gives frozen frames at 120. SO I am a bit confused as to what should be my next steps to trouble shoot this issue. Cheers!
  2. Hi everyone! I'm having a problem with one of my simulations, it already happened in the past but this time i cannot see a solution. Basically, during the process of caching the simulation, the main hard disk (a small ssd with windows) get filled after a couple of frames by temp files. I already setted a custom environment variable for the temp folder but houdini only put little temp files there and not the big ones generated by a simulation. I'm forced to increase the division value of my flip fluid, or there is a way to store the temp files in another folder instead of "C"? I forgot to say that i'm saving the simulation with the "compressed cache" node and not the "import flattank" node.Thanks in advance for any kind of help. Attached the image of my shell and the dop which i use to save a sim files every 100 frames in case of crash.
  3. I have a distruction scene where i have cached the sim but i am between of adding texture on the geomtry but i am not sure how to add texture after caching the sim?
  4. Hello everyone, I used to cache multiple alembic using the technique described here : http://nicholaspfeiffer.com/blog/2016/1/16/houdini-tip-of-the-day-render-multiple-alembic-rops-at-one-time (Long story short : rop network > multiple fetch > a merge > click render > caches every fetch. That's cool !). I thought that it would work the same way if I use this technique to render multiple Dop I/O node. For the first time I want to use the take system to cache multiple sim over the night (changing resolution and parameters). So in an obj node I dropped 2 Dop I/O, set their "Render With Take" parameter on each one, then dropped a Rop Network, two "Fetch" nodes and set their path to the dop I/O "render", dropped a merge, and hit "render". The result expected would be to have the different takes cached but instead I had the Main take cached, two times... What do I do wrong ? Thanks for the help, if a scene is needed I will do a simple version of it Have a great day/night !
  5. Hi Trying to get some clarity on the various caching mechanisms since its such an important part of Houdini's workflow. There is the automatic caching that happens anytime you playback a sim in the Scene view as indicated by the blue progress bar and is limited by RAM unless cache to disk is enabled. And then there are all the cache nodes where you can manually save files to disk. In any application I've used, caching is something that is optionally done to help improve performance and or speed up production workflow. The key word here is optionally. In Houdini, is this case? ie to complete any simulation is it optional or mandatory to save cache files at the various cache nodes? 2nd question> When would you normally cache your files, anytime there is a change upstream from a cache node and your network is taking a long time to cook? 3rd question> In the case of a FLIP simulation there are at least 2 places you can cache your files in the fluidtank_fluid node, the compressed_cache node and the surface_cache node.My understanding is the former is for caching the particle data and the latter for surface meshing. Would you normally always do both, ie after caching out new particle data, immediately cache out new surface mesh files? And lastly, on all cache nodes there is a 'Reload Geometry' button and a 'Load from Disk' checkbox. Don't these duplicate functionality? ie if 'Load from Disk' is checked, doesn't this mean that cached files are loaded automatically and you don't have to click 'Reload Geometry'? Thanks for help with any of the above?
  6. Hey, When you are creating a flipbook and the output is set to ip, the documentation says it is then sent to Mplay. What exactly is happening? I can't find this information in the documentation. Is the flipbook stored in RAM then loaded into Mplay? Or is the flipbook cached to a default temp directory on the hard drive then loaded to Mplay? How can I change the directory where it is being saved? I am new to Houdini [was Maya] so any help is appreciated. Thanks
  7. Hey guys, I'm using a File Cache sop to cache a FEM mesh but I can't figure out how to write it's substeps. I'll use this later to collide with a flip simulation and since the FEM is moving pretty fast I need it's substeps to collide properly with the liquid. $FF doesn't work. I guess it saves integer only... not sure though. Any ideas on how to proceed? Thank's Alvaro
  8. Hey all, I've cached out a cloth sim that's was attached to a static object but when I read it back in with a file node the geometry jumps around in some frames. In the sim in the DOP net it's fine but in the cache it jumps around. Anyone know what's happening?
  9. Hey guys, I assume that the best workflow could be: 1st - Write the particles simulation to disk 2nd - Read the simulation files to generate the mesh (+ cache the geo file) Now, what is the best way to save the particles simulation? Should I do it inside the "particle_fluid" node using a "ROP Output Driver" or a "Flie" node? Should it be connected to the "import_particle" node? Something like this: and how should I read those particle files back? Please let me know if there's a better workflow on it. Thank you, Alvaro
  10. Hi guys I'm working on a big scene and I have about 7 geometry ROP that I want to cache in a specific order. I know if I connect them together Houdini caches all in each frame and it will crash because of low memory. So what is the solution on this case? I want to cache a node and finish it then H automatically goes to another node. Thank you
  11. Hello VFX wizards! I am trying to render out a sim with an RBD alembic animation from maya inside my houdini smoke sim. I can render the scene just fine but my question is with object contributions. in lights you can add contributions that basically layer the exr file with direct lighting, indirect lighting, C, ect, for each light. Can you do this with objects as well? Because in my shot the object swirls around the smoke and has the smoke visible in front of and behind it. I want to be able to essentially render out the RBD object that is spinning as a silhouette on its own layer that comp can add the actual textured object into nuke but still have it in the center of my sim. Is this possible in houdini? *see attached for the LQ take of the shot* smokeRender.v3_LQ.mov
  12. Hello All! So I am importing an alembic file from Maya with animation into Houdini. I want to have this object interact with my pyro smoke sim as a RBD but when i set up the cache to be the RBD object it disappears from the viewport and the sim remains unchanged. Does anyone know of a fix for this?
  13. Hi Guys, I am literally running out of space and I would like to ask you a question: During one of the workshop I followed, the tutor suggested to use the extension "bgeo.sc". I previously used "bgeo.gz". Does anybody know which one is the best and why? Cheers! Andrea
  14. Hey guys, I have a very basic question in Houdini since I'm new to it. How can I reuse a cache for a multiple objects? Thanks!
  15. Hello everyone, I have got a model in a T-pose and a point cache for the animation. I have setup that in houdini using a point VOP but I have no idea how to fracture the character and for the pieces to follow the animation. Here is an example of what I want to do: ------------------------------------------------------------------------------------------------------------------------------------------ I managed to do it with a clothcapture + clothdeform but its really slow, is there any other way to do that?
  16. Hi all, new Indie user here, so be gentle! im trying to do a grain sim, and i have a complex animated collision object. i decided to cache out the collision volume to speed up sim times, as it spend a large proportion of the time "calculating SDF" i followed instructions i found online, and in the static object DOP i set the file mode to "write" and specified the filename as "collision.$f04.simdata" i then set the grain radius very high for a fast result, and ran through the sim. it saved out a series of .simdata files (22 meg each approx.) i then set the file mode to "read" so far so good. however, when i sim again, it -still- spends a similar amount of time "calculating SDF" and doesnt seem any faster.. what did i miss? many thanks for any advice, Robin.
  17. Hi I have a problem when I am trying to render my cached crowd simulation. If I render the dopimport everything renders fine and I get a bunch of soldiers running around. Though as soon as I write my crowd sim to disk as bgeo or bgeo.gz (either using the ROP or the file node) and read them back in something strange happens. In the viewport everything still seems fine but as you can see in the image it does something strange during the render. If I cache my packed crowd sim to alembic it renders fine but it gets really slow and the file is huge compared to a bgeo sequence. So I would rather fix this problem of rendering the bgeo sequence. If I create any other packed object, it renders fine. It just seems to occur when I try to render a crowd simulation that is cached to disk. I am using H14.0.335 Does anyone know what is causing this and how to fix it? Thanks in advance!
  18. I've found a few threads on this topic, but I haven't seen any concrete solutions or explanations that I can understand. I've followed the DT course on how to control your fractures to start, but now I'm getting pretty stuck with what I'm trying to accomplish (explained below). I still have a lot to learn about Houdini, so please let me know if my process if Goal: To cache out a sim of a solid object that fractures a little bit when in the air, then shatters even more when it impacts the ground. I'd then like to take this cached out sim and retime it. My Process: - Make a base object called geo_orig and fracture it with a voronoi fracture sop - Make the geo_orig a packed "RBD fractured object" - Use "glue adjacent" on geo_orig so I can control where the in-air shattering occurs by deleting unwanted constraints. - Then I go into the RBD packed object and hit "make breakable" and cache out the sim with a ROP output driver. - I make a new geometry called geo_read_sim and drop a file node within to read the cached sim - I append the time blend and time shift sops within the geo_read_sim node and that's when the problems start The Problems: - When I play the retimed sim, the geometry freaks out the moment a shatter happens. I think this is due to new points being generated on impact?) - Shattering related, retime unrelated: I can see shattered geometry coming out of unshattered geometry. Like the original geometry stays behind while a duplicate geometry shatters off and penetrates through the old. Any thoughts on why this might be occuring? Research: I've looked at the hip on here, but this deals with retiming a simulation, not a cached one. http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=22492&view=previous&sid=89f08de40a51517484edd04e850202a6 This one deals mostly with volume retiming. http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=118869&sid=b2c7bc6e940c50c42208fa380d53f641 This is the best one. It says on the 1st post of the 2nd page that changing the rbd solver from bullet to rbd and messing with the FPS works... but every time i turn the rbd solver on, I lose the fracturing on impact and glue constraint work. https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=25640&postdays=0&postorder=asc&start=25&sid=353a937f6b8da5898b0a29f9eb1ec0c4 Any help or pointers would really be appreciated. fracture_retime.hiplc
  19. Hi, I am new to houdini and still picking up some basic skill. So I might throw out some very silly or basic question. I am using flipbook to do a preview of my flip simulation which is already being cached out. Each frame takes me around 2gb. When I reimport the cache into my scene, even I have disable simulation, randomly select 1 frame takes me about 1-3 minutes to display my flip particles. It take about 4 hours to make a flipbook preview of 150frames. I wonder is that normal? Any suggestion that I might able to make a quicker preview, or nodes that I can reduce my particles count just for preview purposes? Thank you.
  20. Hi, I have several questions about correct caching approach in Houdini. In DOP Network node's settings there is Cache Simulation parameter. Disabling this parameter results in less memory usage, which is advantage for heavy simulations, however I noticed some strange particle motion in FLIPs simulated that way. When I enabled Cache Simulation, everything was ok. When I simulated Pyro with Caching disabled I didn't notice any problems. So perhaps FLIPs works best with Caching enabled. But, when Houdini reaches memory limit, it starts to cache to disk, probably do Swap partition which slows simulating really a lot. What minimum Cache Memory limit should I set? I have 8 gig ram, but I noticed that when I set limit to 6,5 gigs, RAM would go full anyway. Wouldn't very small Cache Memory limit cause artifacts visible when Caching is disabled? Then there is Explicit Cache option. I understand that it is good to enable it and save 3 last sim files in case of OS / Houdini crash. However I read somewhere on this forum, that it is better for heavy simulations as there is more memory left for simulation instead of cache. What is the best approach for caching heavy simulations on PCs with smaller RAM? I want to focuse my few CPUs on simulating, not to wait till cache is written to slow HDD. My usual approach is to save simulated geometry in bgeos after DOP I/O node, usually throught Hscript. Hope you understand my questions
  21. Hey guys, where does Houdini save the simulation cache files? I'm pretty new to houdini so i'm not sure if it's the right question. What happened is that, yesterday, i've let houdini simulating something for almost an hour and, when i realiseded, it had only half of the sim done. By half i mean the second part. It looks like it have simulated some frames and, because of cache space, it began to delete the first frames to create the new ones. I think that it might be saving the cache files on my primary HD, which is pretty small, so maybe the solution for it would be change where those cache files are saved, in this case to my seconday HD? EDIT: In case you have the same doubt, here's a tutorial showing how to save your sims to disk. Thx, Alvaro
  22. Hey Guys!! I basically want to simulate my flip tank, export the simulation cache, and then read the base fluid cache to simulate whitewater. First i'm exporting my simulation cache using an "Rop_Output_Driver" like this.. Then i drop in a "file_node" to import my cached base fluid .bgeo like this.. I have about 4millions particles in this scene so i'm not expecting a realtime playback, but just jumping to a random frame takes ages, it feels really heavy like it's trying to simulate/cache base fluid again! I want to read the cache files and use them to simulate whitewater without having to simulate my base fluid again.. I've also attached the scene file, hope someone can help me figure this out Scene_File_Caching.hip
  23. Hello all, Im trying to composit a set of images using some vops in the comps/img context. This works fine, however if I update the source images and recomposit, it still uses the old textures from memory. Since it uses a vopcop2gen to load the source images, I cannot use the "Reload Sequence" button as with the file input in cops. so I basically have to force clearing the cache. This is possible using the python shell with the "%texcache -c" command. My problem is that this function doesn't seem to be available outside the python shell, as it doesn't seem to work for callback scripts for instance. Does anybody know the proper syntax for using this function in a callback script, or a different workaround? Twan
  24. Hi all, I'm a creative C++ coder playing with Houdini - pretty beginner but with some understanding of what's going on. I've cached a flip simulation as BGEO sequence, and I'm having trouble adding custom attributes to the points which are dependent on initial position of the point in respect to the initial shape. E.g. let's say I want to melt a teapot, and I want to to use different triangulation parameters for the body and the spout. I.e. I want to mark the spout as "bodypart"==1 and the body as "bodypart"==2 and create groups based on that. This I know how to do: 1. Load the teapot in a geo node. 2. Cookie the spout with a simple shape hilighting the spout area, do points from volume, attribcreate and assign 1 for bodypart 3. repeat for other parts etc. 4. create a flip fluid out of these points and solve it 5. cache the resulting simulation as a BGEO sequence 6. load the BGEO seq, and all of my points still have the custom attributes, and I can use those for meshing and various other visualisations. This works perfectly and does exactly what I need. However problem with this, is if I decide to add/change body parts, I need to re-run the flip solver which makes no sense since the bodypart attrib has no effect on the simulation. Doing this attrib create before the flipsolver makes sense for things like color and viscosity, but it doesn't make sense for attributes which don't affect the sim I think. what I would like to do is: 1. Load a mesh and select different parts of that mesh and assign only attributes which are essential to the flip solver (e.g. Cd, viscosity etc). 2. create a flip fluid out of these points and solve it 3. cache the resulting simulation as a BGEO sequence containing only attributes which are essential to the flip solver 4. load the BGEO seq, and assign new attributes, which I will use for meshing and various other visualisations. If I use the same method (i.e. volume intersections) on the BGEO sequence, it understandably applies the volume intersection every frame, and so the attributes are re-applied every frame to the points inside the volume, and don't move with the points. What I really need is something like "at frame 1, do the cookie and attrib creation, and then maintain those attributes throughout the BGEO sequence" but I can't figure out how to do that in Houdini. Any tips welcome! P.S. I have 'reduce' set to off in my flip solver.
  25. Hi I would want to approximately simulate around 200 frames of pyro sim. 1)I have my explosion simed to disk using a file dop for around 25 frames.There was a power problem and Now again if I want to simulate frames from frame 26. does this means I have to wait again till frame 25 to simulate frame 26 second question is as the simulation range increases towards 40 the bgeo file size is too much even with bgeo.gz compression.and for every frame after frame 40 it takes around 3 hours easily to write out the bgeo files. Is there a better way to optimize this.Almost for every sim I encounter the above two situations Would be great if someone could help me out.