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Everything posted by Pazuzu

  1. Creating Uvs for viscous flip sim

    Hi, Here is the hip setup for the vimeo video about the icecream sim with uvs; Its a very old setup (5+ years). Nothing over-complicated here, not always you have to do Black Magic to solve complex things! I hope it helps! Cheers! Alejandro icecream_vimeo_v001_to_share.hip
  2. How to create voronoi curved surface (no inside group)

    I think a displacement shader is the way to go! So you could use the voronoi pattern directly on your shader to use the center of each voronoi cell and the distance, then use that gradient as your displacement factor to give a concave or convex shape to your main object. In sops you could do the same, but you need a lot of subdivision to accomplish the same as in shading stage. Cheers, Alejandro
  3. Ubuntu 18.04 LTS "Bionic Beaver"

    I had updated 2 workstations 2 weeks ago aprox! And no problems so far! Cheers! Alejandro
  4. Hey Ronald!! Un gustaso ver tu archivo!! Haces muy buen uso de la aplicacion en temas de transformaciones!! Felicitaciones!! Saludos desde Colombia!! Alejandro
  5. Vectorfield in DOPS to affect Fluidsim

    Here is the correction for the file! The problem was that you were using copy mode in the gas calculate, you need to add this pump to your velocity, but also you need to take care with the substeps, that's why I activated also a linear scale multiply mode for the pump to then scale all by the scene FPS. I recommend you also that's is better to use ad-hoc fields (temporal data), it has memory advantages just cleaning that field but also the creation time when dealing with heavy data, for this try to use a gas match field instead. Cheers, Alejandro vectorfield_fluidsim.hipnc
  6. Random link of interest

    Nice TensorFlow + Houdini Clues!! https://qiita.com/takavfx/items/f27cd76604e902199c9d
  7. Particle advection

    Hi, You have many options, one of the them is to just post-sample the smoke density to adjust your particles, for example using the density sampled data to mod you pscale, color or alpha; Or you can sample dynamically the smoke density at the advection stage to for example trigger a custom age to decay your particle attributes. its all up your needs! I hope this helps you! Cheers, Alejandro
  8. Particles along surface

    This method uses the function you want to learn about it! And the nice thing is that is very simple to implement. Of course you need also to implement the goal using forces or modifying directly the position to attract to the surface plus this, and because we are saving the delta, all points will always stick to the rest sampled position. Cheers! Alejandro particles_on surface_aeb.hiplc
  9. Happy 10th Birthday Od[force]

    Congratulations!!! The best Odd forum!
  10. WIP - ok++'s softbodies RnD + .hip files

    Thank you very much for those amazing files!!!
  11. Pyro/smoke fast collider

    If you want better collision behavior, you have two options. By default the smoke/pyro solver uses the Multigrid projection method with just one iteration; This method is very fast but not good to deal with collisions, so try to increase the iterations, that can help a little bit. The second option is to change the projection method to PCG, its slower than multigrid, but gives a much better collision behavior! You can find this option on the Advance/Projection tabs in the solver. I hope this helps you! Alejandro
  12. FLIP smorganic/sheeter effect?

    Hi Michael! The implementation is very different. My technique is more a bunch of hacks than a "Physical Based Solution", mainly to deal with the FLIP/PIC limitations for small scale sims, like packing, volume loss, etc. Another main difference is that mine is particle based (I use also fields, but the forces are apply at particle level), the new ST that comes with H16 is volume based, it behaves very nicely, but if you need very small details you need to increase volume res and also timesteps, loosing the main benefits of the FLIP/PIC method, the speed. I hope that this answer your question! Cheers! Alejandro
  13. Server downtime

    Thank you very much Marc! The forum looks awesome!!
  14. Pyro Clustering Tutorial

    Yes, I usually, flatten everything using vdb, and for the velocity fields, just use a max operation, you will have at the end a vdb combine for every field class in a for each loop.
  15. You're Welcome! Regards speed of computing the fields outside DOPs, is almost the same for both methods; For method (a) to be way faster, you should compute everything in SOPs as with method (b), the main difference is the velocity computation, but is not that bad regards speed. Cheers! Alejandro
  16. (a) This method uses volume based and point based collisions (collision detection). The results are much better at the cost of speed in some cases with huge colliders; Regards velocity this method has 3 modes to automatically compute your collision velocity, "Rigid", "Point" and "Volume". (Look at the Gas Build Collision Mask DOP node for more info) (b) This method uses the standard pic approach to take into account colliders into the system as sdf representations; But at particle level the collision is just a test to see if a particle is inside, if is it, it will take it closer to the isocontour of the collision sdf. For the collision velocity you must compute it yourself. Both are very useful methods. For example when you have large scale sims, the (a) can be a pain of slow with high rez collisions, because the solver has to recompute the collisionmask even if you sample the collision volume from sops, and that can take a lot of time. With (b) method there is no need to compute the collisionmask out of a collision relationship, so it will be faster but you can loose some nice collision behavior, it will be more basic in few words. Cheers! Alejandro
  17. Solver SOP and substeps

    I think doing this is not correct @Cd.x *= decay_val * @TimeInc; Do the math and you will have almost no value to work with; Its better that you subtract and apply a maximum or a clamp after the decay.
  18. Pyro | Multiple Sources with Unique Microsolvers?

    Hey Alvaro, Here is a bit over-complicated setup using a vector field to define the id masks, but you can use also scalar fields directly. In this setup I'm using the id masks ( aka source A, sourceB ) to affect dissipation and turbulence for each source, please look into those "shapers" in the pyro solver. I hope this helps you! Cheers! Alejandro multi.pyro.v1a.hiplc
  19. Pyro | Multiple Sources with Unique Microsolvers?

    You can use an id mask, so this mask should be advected / transported exactly the same as density, this way you can use it to mask whatever filter/effect you want.
  20. You are using a custom expression in the group parameter of the delete sop to filter each piece; So you must edit that expression using spare inputs for the dependencies to work correctly in a compile block. Cheers, Alejandro
  21. Hey, For this to work, you need to fix the expression dependencies in the group parameter for the delete SOP with spare inputs for the compile block to work correctly Cheers, Alejandro
  22. Copy Debris Mesh to Pop

    Hey Alvaro! You need to reset each piece xform first before the copy! Cheers Alejandro copy.fragments.to.particles.v2_FIX.hiplc
  23. Affector matrix with packed

    Nice to hear that!! Cheers! Alejandro
  24. Affector matrix with packed

    Hey Michel! Is this what you are looking for? Cheers!! Alejandro colli_ig_fail_1.hip
  25. Flip fluid collapsing in on itself, how can I prevent this?

    Unfortunately that's one of the limitations of the FLIP method, the volume loss. As Andrew said a particle separation can help to cont-rarest the volume loss on the system. You can try also to apply some drag forces as soon as the fluid start to settle with some speed or pressure conditions, but that can kill a bit the nice momentum. For this kind of FX I really miss SPH, but its so slow; So in my case I come around to this problem using a mix between PBD and FLIP/PIC in my microtension tools, this way the volume loss is less noticeable, but still not as good as the SPH method, I really hope that SESI update some of the SPH microsolvers some day!. I hope that this helps you! Cheers! Alejandro