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Everything posted by Atom

  1. Houdini Bubble burst

    That's not really a burst, that is more of a slow dissolve. Speed it up, perhaps check out some of those experiments done by the SloMo guys on youtube.
  2. Check out Mark's presentation for the Houdini Hive 2020. Around forty minutes into the presentation he talks about how he used a raynode to project a lot of points on to a surface. https://www.sidefx.com/houdini-hive/houdini-hive-worldwide/#mf
  3. Sparse Pyro Upres H18

    I'm wondering what fields I need to export to VDB to get the same look that I see in the viewport (in other DCC packages). When I try to experiment with the volume visualizer, I can't reproduce the same look in the viewport? Any tips on how to match the visualizer to viewport?
  4. Instance random keyframe/animation with Python

    I don't think I would use Python at all, it is still single threaded. It's not going to scale very well when you throw a large object count at it. To randomly offset animations you could use the Retime node. ap_rnd_retime_animation_053120.hiplc
  5. If your electricity is unreliable, you may want to write to .sim files, so you can pick up a simulation if your computer crashes hard.
  6. It could be your hardware is different than the author of the tutorial. It's hard to say in a complex setup without taking a look at the file.
  7. No GPU Utilization on OpenCL with Viscus fluids?

    The only way I have been able to experience OpenCL speed up is by following the rules listed here: https://www.sidefx.com/forum/topic/25234/ That post is for smoke, but it applies to flip and other OpenCL accelerations as well. Turn off the cache, don't continuously emit, and write your result directly to a disk file. Each time you break one of those rules, the CPU comes into play and the GPU advantage drops lower. Updating the viewport every frame pretty much eliminates the OpenCL gains. The most I have been able to get out of flip was about a 35% utilization on my GPU, which I monitored using MSI Afterburner. Try the example file at the link. It's fun to see how quickly you can simulate smoke on your GPU.
  8. No GPU Utilization on OpenCL with Viscus fluids?

    More than likely, your simulation is too complex to fit inside your graphics card. It doesn't take much to break the 11GB boundary and you're not even getting all that if you are using the same card for display, or have other applications open. One thing that will kill OpenCL is continuous emission into a scene, without a sink to remove anything. Try disabling caching on the dopnetwork, and write the result of your simulation directly to disk. Having to update the viewport every frame also diminishes the gains obtained by OpenCL. Particle separation alone is not enough to determine the size of your simulation. It is the box size of your domain that is divided by the particle separation that determines ram usage. If your box size grows over time, your memory footprint will grow. Try looking into the new sparse solver. Even though it is CPU based, in some situations it can outperform OpenCL.
  9. If there is no input, I don't believe you can do that. However, you could set the weight to 1 and control the emission color via an attribute. Use the brightness of the color to drive your effect.
  10. Gasupres doesn't work

    A few of things. On the gasupres node make sure you set the Fluid Type to Smoke, not Pyro. Also, you have to drop down an attribute wrangle between the lores and the upres node to create a detail attribute named @timescale. When this attribute is missing the time scale defaults to 0, which is no motion. Set it to 1.0 to test, but try other values to speed up or slow down the upres. On the output of the lores dopnet, you need to add temperature and vel fields which get forwarded to the upres network. Without those, the upres simulation won't work. ap_smoke_upres.hiplc
  11. Houdini Hive 2020

    I worked through Mikael Petersen's crowd based thingie setup. I'll post it here. If anyone else has setups from the hive 2020, drop them in this thread. ap_mp_blendshape_crowd_character_052120.hiplc
  12. Redshift Proxy with relative path [SOLVED]

    I don't think you need the slash in front of $HIP. Try this instead. $HIP/rs_proxy/teapot.0001.rs Also for local instancing, don't use instancefile, use its companion, instance. s@instance = "/obj/teapot_rs/OUT/";
  13. Vellum Age

    AFAIK, the standard vellum setup does not accept animated input, so @age is simply the frame number. You can assign an @id to the primitives and the solver will pass it through. Then you could post-sim process using a for loop to operate on each piece. Here is Matt's setup with that modification. ap_me_vellum_confetti_052020.hiplc
  14. I had the same problem, RIS doesn't seem to work anymore in H18. The renderman delegate does work under LOPs, however. Give that a try.
  15. Get values of parms from within python module

    The safest way is to check that the value you fetch is valid before you attempt to evaluate the parameter. node = hou.node('/obj/autosaver1') if node != None: # Success in obtaining a reference to the node. p = node.parm("my_parm") if p != None: # Success in obtaining a reference to parm. my_value = p.eval() else: print "parm not found" else: print "node not found"
  16. Displacement from Normal map

    You could apply the normal map to a grid and render it from the top view to produce a greyscale image. If you have the companion diffuse map for the normal map, you load it into Awesome Bump and produce a matching set. https://github.com/kmkolasinski/AwesomeBump
  17. Abstracting a bunch of photos in TOPs

    I get an incomplete definition on stan_trace. Is there somewhere I can download that node? Is it part of LABs?
  18. Pyro sim to bgeo.sc vs directly to vdb

    I have started using .VDB instead of .bgeo.sc for all my volume work. Just write directly to .VDB. Give it a try. If you are at maximum ram, and the convert node throws you over the limit, increase your divsize by a little to gain back the memory that you lost.
  19. Better Tornado Result

    Check out Fencer's localized drag setup. You could place a tube around the portion of the tornado you want to affect and alter the code in the drag node to use the distance from the points of the cone to affect how strongly the drag takes place. For instance, up to distance 1 from the center, no drag will be applied, then more farther away. Anything after distance 3 will get 50% drag. vector p1 = point(0, "P", 0); float dis = distance(p1, @P); @vel *= fit(dis, 1, 3, 1, 0.5); This also let's you crank up the velocity a bit on the source node.
  20. Particle sim velocity problem

    I'm not sure what your exact goal is, but here is an attempt at dragging particles along with the moving shape element. ap_OdForceParticleSim.hipnc
  21. Better Tornado Result

    I worked on a tornado of photos a couple of years back. I ended up making two sparse tornadoes exactly on top of one another, but spinning at different speeds. It helped the final look. You might be able to accomplish that with a Retime of the original if you already have it cached out. Adding debris spinning around might be nice if it applies to your scene. Your setup looks pretty good overall.
  22. Streaky Portal Effect [SOLVED]

    I show how to build my setup in this video.
  23. Atom's Video Tutorials

    I put together a short video on how to make smoke fall into a hole. There is also a setup at the end that shows how to generate a fake @heat field using the VDB Diagnostics node.
  24. Atom's Video Tutorials

    Hello Everyone, I put together a short video tutorial on how to use the particle system to break glue bonds that are holding together fractured geometry. You can view the video here: I have other videos posted in this link as well. http://forums.odforce.net/topic/17105-short-and-sweet-op-centric-lessons/page-5#entry127846
  25. I would consider resizing the entire set up to scale down to a more reasonable size. Reduce the scale on every item by 100 times. Don't forget to bring the domain size down as well.