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Found 11 results

  1. Hello, In a small-scale FLIP-Fluid simulation, I need to improve the flow of fluid particles, so I tried these settings: 1) FlipSolver -> Particle Motion-> Reseeding -> Surface Oversampling = 20 2) FlipObject-> Particle Separation = 0.01, Particle Radius Scale = 0.66, Grid Scale = 0.8 3) FlipSolver -> Volume Motion -> Velocity Transfer -> APIC(Swirly) 4) FlipSolver -> Volume Motion -> Surface Tension = 20 5) FlipSolver -> Substeps Tab -> Min Substeps=10, Max Substeps=20 6) I add a POP-Drag node (Air Resistance = 1) to the simulation. But the result is not that satisfying! How can I improve it? Thanks for helping. FLIP_Fluid.mp4
  2. Bullet deforming static geometry substeps

    Hello guys. I found strange behavior in bullet. I have medieval wooden cart, full of heavy stones, moving fast from the hill. By default, bullet have 10 substeps, should be good enought. Cart is rigged, and it is deformed, twisted so I need him as deforming static object. If I check cart with timeblend, frame increment 0.1 in SOPs, I can see slight movement of geo, dive to DOPs, bullet stones fall, but my cart, deformed static geo is jumping on full frames. No movement inbetween frames. That causes ofcourse incorect collisions and all kind of bad things. I tested in H18, H18.5 same results. So I never had collision geometry substeps??? Is there some easy fix, how to force bullet recompute deforming static object every given substep? Thanks a lot.
  3. Substeps cache problem

    Hello, I need to save caches and use it as Slow Motion 10x . I use increment in rop - file cache, but it seems it does not work. Substeps 2, 4 are ok but 5 and 10 not, viz pict. Its some bug? I can use $N, its asset sim on zero pos and use timeshift for now but I would prefer proper substeps saves. Thanks a lot.
  4. pyro and CFL relationship

    Hello, In order to have better collisions in my simulation, I lowered my CFL condition and increased my max substeps (on the solver). Inside my pyro solver, I saw that on the gas substep, the CFL condition was divided by the timescale, I would like to know why? Do you know how exactly the CFL works? Thank you in advance, (I made a basic scene to highlight my question) PYRO__substeps_cfl.hipnc PYRO__substeps_cfl.hipnc
  5. Hello, I have a popnet with that emits one particle every 10 frames and I need to increase substeps to get more accurate result...however when I increase substeps it affects pop source and emits more particles. For example if I have 3 substeps, it will emit 3 particles instead of one. I've tried using gasintermittentsolve but when using that it just won't emit anything at all unless frames between solves is set to 1. Is there any other workaround for this? Thanks
  6. FPS vs Substeps

    Hi, I have a question about fast moving sources and simulation with fast movement. Which typically produces better results, using more substeps or a higher frame rate? Or using a combination of the two? Note the end goal isn't slow motion, just better accuracy. Or do they produce the same results ( double frame rate vs twice as many substeps)? Thanks, E
  7. Hi guys! Suppose I have a sphere filled with particles, and there is a growth map on it. I am activating the particles based on this growth map and a wind force blows the active particles away. I am only emitting on the first frame. copying the growth map attrbs via sop solver. If my wind force is too high it will cause gaps in between the particles as they are pulled away. Will dop/pop substeps work properly and fill the gaps when there is no emission happening? The growth map has in between frames, I've put a time blend sop to be sure. But I am having a tough time getting the substeps to work Would be great if anyone has any suggestions. Thanks!
  8. read back substeps

    hey! I'm simming a flip fluid sim and I'm writing out substeps to disk in order to do a slow mo effect. At the moment I'm having something like this for 4 substeps testretime.125.25.bgeo.sc testretime.125.5.bgeo.sc testretime.125.75.bgeo.sc testretime.125.bgeo.sc testretime.126.25.bgeo.sc testretime.126.5.bgeo.sc testretime.126.75.bgeo.sc testretime.126.bgeo.sc testretime.127.25.bgeo.sc testretime.127.5.bgeo.sc testretime.127.75.bgeo.sc testretime.127.bgeo.sc how can I read this info back and render it in mantra so that 125.25 becomes 126, 125.5 becomes 127 and so on? should I rename those frame by hand? or there's something smarter?
  9. Hey Guys , i have a fast moving flip source , and cant get smooth shape , it look like emitter shape while emitting , i tried many different solutions like , putting time blend sop,trail sop , increasing substeps but always get same result . i had this problem in realflow too , but i fixed that by incearesing min substeps , but it didnt work in houdini , is there any solution for fixing this problem in houdini ? thanks
  10. Sub Steps Cache

    Hey guys, I'm using a File Cache sop to cache a FEM mesh but I can't figure out how to write it's substeps. I'll use this later to collide with a flip simulation and since the FEM is moving pretty fast I need it's substeps to collide properly with the liquid. $FF doesn't work. I guess it saves integer only... not sure though. Any ideas on how to proceed? Thank's Alvaro
  11. Smoke motion blur from alembic

    I am having a problem with getting continuous smoke emitting from an object. The emitter object is parented to an imported (and animated) alembic file which is moving quite fast. To try and rectify this I watched Peter Quint's videos on smoke in H12, and in the second video (the part on moving objects and motion blur) he mentions that to activate motion blur the animation (of the emitter object) should be on geometry level as opposed to the scene level. Could it be that my motion blur (and essentially continuous smoke) is not working because the animation is coming from the alembic file? And if there is another way to get continuous smoke emitting from a fast moving object (like smoke "substeps") please let me know =/ Thanks!