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Everything posted by Atom

  1. Flip Fluids deforming collision objects

    Here is the i@stopped attribute included inside the if statement. I dropped the viscosity threshold, quite a bit, so the fluid would come to a stop quicker. if (@viscosity>3600){ @viscosity = 3600; @v = set(0,0,0); i@stopped = 1; } ap_SimCon1.hiplc
  2. Check out this thread. You need to use special named attributes to change the values.
  3. Houdini "proxy"

    The @instancefile attribute is only for file based objects, you can't use op: pathing. In your case, write the rubbertoy to the disc, then reference that file. To leverage local geometry that is installed in your scene, there is a companion attribute @instance. You can use the op: with that attribute. But referencing large pieces of geometry, from memory, instead of disc, may reduce some of the gains achieved by instancing.
  4. A keyframe every frame? That kind of defeats the purpose of MPEG. Try using the Animation codec, instead.
  5. Pro tips for flip meshing?

    One way to make better use of the particles that you already have, is to increase the Surface Oversampling of the reseeding. It defaults to 1.5, but I typically raise it up to 5-9, or even higher (24-36). This will spread out the particles, that are contained within each voxel. From the look I see in your video, you do have the Influence and Drop scale set very close to one another. Try widening the gab between those two values.
  6. Houdini "proxy"

    You can leverage the split output nature of the SOP network. Have two attribute wrangles at the end. One is for rendering and the other is for the viewport. Assign the filename to the hi-res geometry inside the RENDER version of the attribute wrangle. CTRL-CLICK on the Display flag of a node to move the RENDER flag to that node.
  7. biological modelling methods

    Here is one way to add UVs to those lines. It does not convert to VDB, it uses a sweep to loft the mesh along the line. If you need VDB output, you can do that at the end and use an AttributeInterpolate to transfer the UVs to your final mesh. This setup drops in an attribute VOP to add a secondary displacement map along the length of each spline. This means mesh displacement is happening prior to render, but you can still add more normal maps or bump maps to the surface when you get to adding materials. ap_uv_curly_curves_081819.hiplc
  8. I'm not sure why you're not just creating a collision object? You can also look into the minpos() function. which will help keep points on a surface. http://www.tokeru.com/cgwiki/index.php?title=HoudiniDops#Pop_stick_to_surface
  9. Particles — Redshift Emission

    Make sure you have enabled global illumination. You will get no emission from Redshift, until you do.
  10. FLIP colliders flickering

    Make sure your collision object has no holes in it. Most characters do have holes (such as the eyes, mouth etc) that you may need to fill. A polyfill node ,set to single polygon, often is all you need.
  11. FLIP Divergence

    That is a nice tip, unlocking the solver and changing the drop down to Set Always. Most of the time when I work with FLIP I also change the Grid Scale to 1.0 on the FLIP Object and then head over to the Reseeding tab of the FLIP Solver. I typically add one more particle per voxel to the Particle Per Voxel expression. ceil(pow(ch("../flipfluidobject/gridscale"), 3))+1 Then I increase the surface over sampling to somewhere like 6-18. this gif shows an over sampling of 9. Over sampling helps smooth things out, so you can use a higher particle separation, in some cases. ap_animated_FLIP_Divergence_v0100.hiplc
  12. Converting Hard Constraints into Glue Constraints Help

    You do have a misspelling of the attribute, @strength.
  13. Quads instead of triangles

    The simplest trick is to drop down a VDBFromPolygons then drop down a ConvertVDB (defaults to volume, change to polygons) to turn the volume back into polygons. You will get all quads, but not necessarily flowing loop cuts.
  14. UV out of range

    Make sure you use SPACE-5 in the viewport to visualize the layout of your UVs. Mari NC only supports one UDIM tile so you have to fit all your UVs within that first box.
  15. Apply force on certain rbd objects

    The force to a group may be working, but the members of that group might still be bound by constraints to members that are not in the group. If you have constraints to the windows, that could be it. Try turning the windows into a static collision object, instead...?
  16. Central gravity force

    It may seem odd, but you can reference the location of a moving NULL, and tie it to the goal vector of a pop steer seek, using a relative reference. Then all the points in the RBD sim, that are in range of the field, will be attracted to it. The force is activated by animation, which causes the RBD chunks to attract to the green NULL. ap_particles_attract_to_point.hiplc
  17. Houdini 18 Wishlist

    Once again, I request talking lip synch characters. Here is the way I want it to work. I supply a wave file that is used to activated the mouth. I supply a text file that contains the words that the wave file says. I press a button and I get a talking head that I can render. The head should be shapeable, using controls, similar to make human or other character generating tools. I think that's it, two files, one button.
  18. Dynamically add wires into wire solver

    You're on the right track with time shift. Shift to the end of the timeline, then reveal the wires, over time, by deleting the ones who's @id does not yet exist.
  19. Vellum Aerodynamic Lift

    Check out the cloth+pyro.hipnc, at this link. It demonstrates how to achieve lift in cloth (not vellum) by making it responsive to the temperature field of a pyro simulation.
  20. keep uvs on flip anim

    You need to unpack Alembic before you begin processing. Here is a revised setup using a .abc file. There were some errors in your file. There are some UV anomalies, but if you increase the FLIP resolution (which is matched to the pointsfromvolume resolution) the anomalies become less obvious. mb_african_femal_01.abc ap_flip_UV_transfer_001.hiplc
  21. rotate flip pump source

    It is common practice to not animate DOP sources at the /obj level. I moved your spinning animation into the SOP level and cleared the /obj level animation. Also, you don't need that rest. It seems to be locking your vel source to frame #1. AP_01 pump-rotate-test 03.hipnc
  22. Emit random object in RBD Packed object

    Check out Matt's setups. http://www.tokeru.com/cgwiki/index.php?title=HoudiniDops#Emit_packed_prims_into_RBD_sim
  23. You could use the actual NASA data.
  24. I was playing around with an RBD domino setup and extended it to accept a graphics based image (i.e. logo) for input. The Trace node converts the image to the outline of the logo, which is connected to a CopyToPoints, to setup the dominoes. ap_logo_dominoes_071819.hiplc
  25. Mesh from Lines (leaf)

    Triangulate2D node can get you started, then you can play around with remeshing or poly reduce. ap_Leaf_v0102.hiplc