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KarlRichter last won the day on June 14

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  1. Evenly Distributed Hexagons On A Object

    Here is a cool trick that will work just for hexagons. Use a remesh node to turn your mesh into nice even triangles, then use the divide node with "compute dual" checked. Instant hexagons! Edit: Well, never mind. I guess that makes some pentagons too. Oh well...
  2. keep uvs on flip anim

    A while back i was playing with the UV fluid mesh seam issue with some amount of success. See attached for an example. uv_fluid_mesh.hip
  3. Your scene is using some external hda so it doesn't open right for me, but I suspect that you are over the geo display limitation. It is very easy to go over this threshold with instances because it's so easy to make so many of them! The default is set to 20 million polygons in the display options -> optimize tab.
  4. Liquid mix export to Maya-Arnold

    To be able to access alembic point data exported from Houdini in Maya with Arnold, you must export the attributes as vertex color data. The trick here is that it MUST be a color type attribute in houdini, a regular vector will not work, and it MUST be a vertex class attribute. So if you were to create a color node and use one of the RGB channels as your "weight", and then promote it to a vertex attribute it would export properly. In order to access this data in Maya with Arnold, you need to check the "Export Vertex Colors" box under the Arnold tab on the alembic shape node. Then you can use the "aiUserDataColor" node in a shader network to put your weight attribute to work using a ramp or something. Also, you can get motion blur data from alembic files with changing topology this way as well. Export your velocity vector as a vertex color and then use the "motion vector source" attribute on the shape node to access the velocity data.
  5. Grains - how to make 'em bounce off surfaces

    Look closer. I know it seems like setting ispbd to 0 would disable the grains entirely, but it doesn't! The particles bounce, but still maintain distance. It's hard to see in your test scene so I made one that illustrates this better. ispbd_test.hipnc The ispdb flag does not disable grains, it is there to tell the pop solver that a given particle is under control of pdb, so don't apply all the regular pop physics. Indecently, before I was aware of this flag I would fake a bounce by giving each particle a random upward velocity on the first impact.
  6. Grains - how to make 'em bounce off surfaces

    Set the attribute "ispbd" to 0. See attached. collision_grains_v02.hipnc
  7. Bee Movement

    Here is a quick example of how you could achieve this kind of effect with the grain solver. If you wanted to get fancy with this, you could constrain pairs of grains together to more accurately represent the bee body shape. bees.hip
  8. 2D vellum Simulation

    If you use a sop solver to explicitly set the y point values of the cloth geo and an additional sop solver to do the same to the constraint geo, you can very effectively constrain your sim to just two axis. See attached for example. BTW, it may seem that you only need to manipulate the "Geometry" data, and in the simple attached demo that seems to work fine, however I have found that with complex vellum sims you really need to run over the "ConstraintGeometry" data as well. vallum_x_constraint.hip
  9. HTOA missing shaders in new versions

    The Arnold shaders are under "shading", but the "skin_SSS" shader has been deprecated as of Arnold 5:
  10. Here is an example using rest fields to drive displacement for the purpose of adding detail to a smoke sim, but it could be used for any kind of displacement. There is an example .hip in the Vimeo description.
  11. cloth capture weights

    Is there really no (easy) way to edit the weights generated by the "cloth capture" sop, or am I totally missing something? It seems like the "edit capture weights" shelf tool should do it, but I guess it's for bone weights only. Kind of a big omission, especially with the the addition of the new Vellum stuff. What is the solution to transfer a low res cloth sim to a hi res asset? I am currently getting ok results with the point deformer, better then with the cloth deformer, but it would be really nice to adjust weights on a more granular level. I have been comparing the results between the new vellum cloth and Mayas ncloth for use in an upcoming project. While I have been getting pretty good (and fast!) sims with vellum, I have been having issues finding a reliable way to transfer the sim to the render asset.
  12. calm flip water in custom conteiner

    Here is a simple setup that gets your pool very still by damping the vel field in your pre-roll puddle_testt_v02.hip
  13. This excellent tutorial will help you solve your orient issue:
  14. Wire constrained to two objects

    Here is one way to do it using wire constraints. See attached. wire_constraint_example.hip
  15. Some FLIP questions

    Rather than directly answering your questions, I would suggest pursuing a deeper understanding of FLIP fluids. I highly recommend this masterclass, it really opened my eyes: