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Everything posted by Skybar

  1. Make boat react to waves?

    I have a small boat which is running through a FLIP wave tank. Right now I have only built the basics with the flip, and with the boat running along Z-axis with $F/3. I haven't tweaked it yet so the paddlewheels are kinda crazy, see the attached movie. Basically what I'm wondering is; is there a way to make the boat react to the small waves? The only thing I can think of is hand animating it, but that won't really be correct and it will be quite hard to nail, to be honest. My second thought was to make the whole boat dynamic, make it float and actually make the paddlewheels push it along. But that seems quite excessive. Anyone have some ideas on how to do this? edit: It wouldn't let me attach anything, view here instead: https://vimeo.com/68658489 password = odforce
  2. timeblend Orient Quaternion

    That option is new in 16.5 though, he might not be using it.
  3. Custom Z-Depth Pass

    In your shader you can just grab 'P' (which is already in camera space because we are in a shader), take the Z component and fit it between what you want.
  4. How much memory do you use?

    It depends what you do and what your goal is. I'd say start with 64gb and then buy more later if you need it. Less ram also forces you to learn how to be more efficient, as well, so it's not necessarily a bad thing. And if you need to ask if you need more you probably don't at this point.
  5. missing reflections from fire

    It's because you don't have a density volume. The candle shelftool doesn't use density at all in the simulation (no idea why its setup like that).
  6. Cache Optimization

    If you've set up the FLIP from the shelf, it gives you a pretty good and optimized way of caching it out. Use that.
  7. Distance from center in shops

    How are you calculating it? If you just use P in the shader, the position will be in screenspace and not world.
  8. A quicktip is to use the Deformation Wrangle when doing stuff like this. It will take care of your normals and stuff, rotating them too. When just using a Point Wrangle and modifying P the normals doesn't follow (or any other vectors, velocity for example).
  9. renderstate vs packed fragments

    I found this in the docs:
  10. Volumes change density/quality in render

    Have you scaled the camera? Is it camera motion blur caused by the camera-switching?
  11. Voxelisation Effect

    You can use the VDB Visualize Tree SOP, set Active Voxels to "Solid Boxes" - and then remove all red boxes. Then you get a box per voxel only where you need them.
  12. Time-based paramater in /mat?

    Yes, but those parameters are already toplevel ones on a Material Builder node. Isn't the whole point of /mat to build shaders directly with VOPs in the context? I might have answered my own question, encase your VOPs in a material builder; but that sounds counter-intuitive to what I thought /mat was supposed to be.
  13. How can I have a parameter based on time in /mat? Right now I'm trying to read in a point cloud like this: "/my/disk/pointcloud.$F.bgeo", but it doesn't work unless I change $F to a static framenumber. In VOPs/SHOPs you have to promote the parameter to toplevel if you want to have it time-based, but you can't do that in /mat.. Does anyone know what you are "supposed" to do? I really don't understand it.
  14. Time-based paramater in /mat?

    No it doesn't I'm afraid. The thing is that you can't have time-based parameters in VOPs, but the whole /mat context is VOPs so I have no idea how you're supposed to do it.
  15. This video explains it pretty good: https://www.youtube.com/watch?v=m9AT7H4GGrA
  16. Help With Speeding Up Render

    I've solved crawling highlights before by adding the "jitter" parameter to the mantra rop and turning it off. It was a while ago last time so dont know if anything has changed, but you can try that.
  17. It works if you do: int iteration = detail(-1, "iteration", 0); float rampPos = fit01(rand(iteration),0,1); @Cd = chramp("ramp",rampPos);
  18. Wire Sim with Changing Point Count Source

    In that file, set the Resample to maximum segments instead of length. Then gives you a constant point count and it works.
  19. Wire Sim with Changing Point Count Source

    Don't change the point count . You can do something like this, but in your case timeshift your curve to the last frame and match the animation with the carve instead: growingWire.hipnc You could probably sim the wire with grains+constraints as well, might be a bit more forgiving with changing pointcounts given that it's just particles.
  20. Persistent Point ID on Changing Topology

    You should add IDs before the topology changes or at the same time the point gets created during a sim. Assigning IDs after the fact is close to impossible. Should be straightforward enough with a cloth sim though. Take a look at how POPs does IDs and replicate that.
  21. Sounds like you are on the right track. I think Attribute Promote SOP deletes the original attribute by default, so untick that option if you haven't and you should be able to use it to compare with.
  22. I'm not a presenter but I do that too. Force of habit.
  23. That sounds interesting Mark, didn't know about that. Does this translate into the same thing for Mantra?
  24. Invert volume

    @density = 1-@density; Or use complement in VOPs.
  25. It's the volume representation of that object, that is what the pyro solver will see and collide with. Not sure why it shows up like that with no way to control it, but I probably have never done packed bullet and pyro in the same sim. You can see it in the Geometry Spreadsheet under sphere_object1/Geometry/Volume that it's in fact "there", and not just a ghost.