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Everything posted by Midasssilver

  1. Vellum Scale by Attribute Not Working

    Point groups are definitely allowed on the vellum constraints node... that's how you specify which points are constrained. As far as changing vellum constraints over time, if you use the vellum solver at the sop level, the constraints are only initialized at the first frame. If you want them to animate over time, you either need to use a Vellum Constraint Property Dop node inside of dops, or dive inside of the vellum solver and add it there (but it might have a different name there). See the attached file for an example. VELLUM_ANIMATED_CD_V03.hiplc
  2. This forum post outlines one way: https://www.sidefx.com/forum/topic/51796/ In addition to that, I know there's a way to inherit the uvs into the flip without using the rest field. Couldn't find that post in the time I had, but I'm sure it's on this forum or on sidefx.
  3. Fracturing a baked animation, how?

    You need to fracture the geometry at the rest frame, and then transfer the animation from the baked alembic to the fractured character.
  4. Transfert attribute color from geo to another geo

    You need to add a solver sop and aggregate color over time. Using an expression like this in an attribute wrangle inside the solver. Have the first input to the wrangle be input 1 and the second input be prev_frame. Then use this code: Cd2 = point(1, "Cd", @ptnum); @Cd += Cd2; @Cd = clamp(@Cd, 0, 1);
  5. Shots fired!
  6. Exporting curves from houdini apprentice

    .obj? I don't think apprentice supports abc exporting, so if they are animated, you are not gunna have a good time
  7. Hi there, I replied to your post on sidefx, so I'll just copy my reply here: " If I were you'd I'd create a scene yourself, then post your hip file if you want it to get closer to your reference. People probably aren't going to make files from scratch for you. Lowering the dissipation isn't going to help you. You want your smoke to last for a while. I'd suggest playing with the turbulence settings and use the control field to craft when the noise hits it. Then also play a lot with the initial velocity, and possibly add collision geometry for the cannon so the smoke shoots out in the right shape. Whichever method you choose, seeing your scene will help us give you advice and maybe steer you in the right direction. "
  8. How to make a cool explosion

    Start with something like a sphere. Emit particles from it, shooting out in the shape you want. Copy a sphere with scattered points on it, onto each particle. Have each copied sphere trail, so you end up with a trail of points. That will be your fuel source. The length of the trail of points is the length of fuel you will have. How quickly that fuel dissipates is controlled on the pyro solver. Then play with the cooling rate, turbulence and disturbance to get what you are looking for.
  9. pyro vortex going out of bounds

    Yeah, you need some velocity pushing the smoke inwards. If you don't angle the velocity inwards, it's just going to shoot outwards from the spin. If I were you, I'd set up another velocity field that just sucks the smoke inwards and get that looking good, then add an additional velocity force that adds the radial velocity, and add just enough that the smoke doesn't shoot out too far.
  10. That's odd. Well packing just changes how it is exported. I have run into mismatched attributes causing that kind of error. When you pack the objects, the attributes get stored inside the pack, so that might be why it exports correctly when you pack (it avoids the mismatched attribute problem). This is hypothetical, but I was running into the same issue the last couple days. In my case, I just wrote out the alembics separately. You can see mismatched attributes on the merge, there will be a little warning on it that declares which attributes are mismatched. One test would be wiping all attributes on both objects, merging, and writing them out without packing and see if that works.
  11. I assume that a mismatched attribute that is essential to your network is being overwritten or deleted. The merge should successfully prepare multiple objects for export. When it says bypassing this node causes it to export the first input, they mean disabling the node itself. Since you aren't doing that, I'd suggest trying to write out each part and seeing if that works first.
  12. Weird. I've been running into something similar on my Indie on Steam. Sometimes my render view glitches, and when I click the render button, nothing starts. If I create a new render tab, then it usually fixes itself, but it can happen again. If closing your session and re-opening it doesn't resolve your issue, it might be a little more serious than a simple glitch.
  13. Alembic Path Attribute & Voronoi Fracture

    Post a hip and Ill check it out for ya! Make sure to lock the .abc so we can work with the scene. Thx
  14. Copy To Points/Normals

    On the copy sop, there is a Use Template Point attributes parameter that you need to enable to make sure the attributes are copied from the points onto your copied geo.
  15. Earthquake in Paris

    I feel like a fire coming off Notre Dame would be more realistic
  16. Boolean Shatter Node Giving Strange Artifacts

    Tried to resolve your issue, and after inspecting your geo, I found that that is likely a large part of the problem. Inspect the mesh around the pants - see the holes and messed up geo? That won't boolean correctly, which also explains why the technique worked on simple geo, but not your model. Unfortunately I can't tell you how to fix your model, but perhaps converting to vdb and remeshing it could get you what you need. One thing I suggest while troubleshooting this, is try using a single cutter first, and see if the problem persists, then increase the count of the cutters after that.
  17. Animated colliding objects

    Pretty cool. I didn't know u could do that I'm going to check it out and hopefully learn some stuff
  18. how to import point (attribute VOP)

    I have no idea how you gauged that that was what he was trying to do lol
  19. how to import point (attribute VOP)

    Sorry, I don't really understand what you are trying to do. An attribute vop does run on all points that are plugged into the attribute vop. Anything done inside the attribute vop will run on all the points. Then you said you want the same gradient on all the points. That part really doesnt make sense. It looks like you have a color gradient on your grid, but the only reason you are seeing that is because it is a collection of points. Each point only has 1 color, so it's impossible to have a gradient of color on any one point. Maybe ask your same question differently and it will make more sense.
  20. Animated colliding objects

    That doesn't make much sense. The 3 rbd objects bumping into one another is fine. But you said you wanted to animate the objects and have pin constraints based on that animation? Normally you would pin points of an object, not an entire object. You can bring your objects into DOPs with their animation, but then they won't be active objects, they will be static deforming objects. What I'm trying to say is, it is not easy to blend animation and dynamics. I know it can be done, but not very easily. And, I'm pretty certain that the way that would be accomplished wouldn't be with constraints.
  21. Try dropping in a clean sop on your unpacked geo before writing out the alembic. That might fix it. If you are afraid its a Houdini to 3DS max thing, import the alembic back into Houdini and verify if the broken geo is still a thing.
  22. Animated colliding objects

    Well, you can certainly sim one object, then convert that cache to a collision object in another sim, so you can mix animated and rbd objects that way. You can also crumble apart an animated object as well, by preserving @animated on the objects you want. Unfortunately what you are describing doesn't seem easy. With a RBD fracture, you are able to distinguish between which pieces are animated and which are simulated over time, but as far as somehow having an object both retain animation, but also dynamically simmed, and seamlessly bridge the gap between the two doesn't seem like an easy feet. I have seen people mention getting mutual feedback between RBD objects, so maybe something like that could be accomplished. My only question for you is why do you need to hand animate the furniture in the first place? Can't you just give it an initial velocity and rotate it in the right direction, to accomplish the same thing?
  23. [SOLVED] Determining a volumes max velocity

    On the dop i/o, there is a compute min/max option. That will show you the max and min vel for each float of the vector. I tried to figure out how to get the length of the velocity from that, and I didn't have much success BUT I did think of a potential work around. Since you can get the length of the velocity measured from points, you can use the volume to advect points, and ramp down how much vel is received on the popadvectbyvolume. As long as the points move with the smoke sim, you should be able to use those to get a max length of your velocity.
  24. Rigid Bodies keep moving

    You've got some weird stuff going on with your collision geometry. Look at the ground plane move half way through the movie; that's bound to cause some weird movement.
  25. imported Alembic broken UVs

    Something seems weird with the obj/alembic export you used. I wrote out a obj from the alembic, and I got the same uvs on the alembic and the obj, so I'm not certain what went wrong with your setup. In the attached scene, you can see that they are the same. alembic_import_UVs_02.hip