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Everything posted by Skybar

  1. Volumes change density/quality in render

    Have you scaled the camera? Is it camera motion blur caused by the camera-switching?
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. This video explains it pretty good: https://www.youtube.com/watch?v=m9AT7H4GGrA
  7. 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.
  8. It works if you do: int iteration = detail(-1, "iteration", 0); float rampPos = fit01(rand(iteration),0,1); @Cd = chramp("ramp",rampPos);
  9. 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.
  10. 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.
  11. 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.
  12. 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.
  13. I'm not a presenter but I do that too. Force of habit.
  14. That sounds interesting Mark, didn't know about that. Does this translate into the same thing for Mantra?
  15. Invert volume

    @density = 1-@density; Or use complement in VOPs.
  16. 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.
  17. Delete by Volume

    Use the Solver SOP.
  18. I've been using the Instance SOP a lot lately, its quite nice. It's really easy controlling what to instance with the instancepath string attribute, if you have 1 piece per file on disk.
  19. Activation expression

    if(condition, true, false) if($FF < 10, 1, 0) $FF<10 works too
  20. Import other image networks in COPs

    Use the Fetch COP.
  21. Server downtime

    Going to www.odforce.net leads to an error, forums.odforce.net works fine though.
  22. Actually no, sorry, you are right. It does match the Reference Field if the field already exists. Sorry for confusing you :). Not sure if it is possible to match a field from another object like that, but someone else might know.
  23. Gas Match Field DOP creates a new field. "Field" is the name of the new field, and "Reference Field" is the field it should take it's dimensions from. So you dont have to create the new field beforehand because that is what it already does. Keep in mind that this only creates a new, empty field. You have to separately copy/add data to it afterwards.
  24. Houdini 17 Wishlist

    I think it's been said that you should send them an email if you want something verbified/compilable. If it's an easy fix you might even be lucky and get it in a daily build.
  25. Subdivided sphere issue

    I got a couple of spheres I want to render with refraction. They are pretty low res, and I wanted to subdivide them at rendertime. However the poles get all screwed up (see pictures) and this is clearly visible in the refraction. I've noticed this lots of times before but it never really was an issue. Is there an easy fix for this? Probably a noob question but I have no clue really. I could go back and use the "polygon"-sphere (made up of only tris) instead, but then I'd have to resim and all that. Cheers!