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Everything posted by dark_cry

  1. Hi, I have a case where I have, lets say an object which comes from bulelt sim, with v and w. Based on that object, I want to drive another bullet sim, updating v and w, so the rest would be calculated by bulllet sim. In the scene I attached it works pretty much, except it flips at some point. I understand that there should be some catches on quaternions. I suppose, there should be some sort of angle check and etc, but can't make it work... update_angularv.hip
  2. Hi all, Is there any way to glue active objects to non active deforming object? I tried to update glue position every frame so that it could stick to passive object, but looks like it doesn't work. Attaching hip to be clear Cheers, A glueToDeform.hipnc
  3. Hi there, I'm trying to control flip particle count per voxel. The idea is to evaluate particle count per voxel on every step (Gas Particle Count) and then analyze the pcount field.. If pcount > n - delete some of particles (pcount - n) to make n numbers. And if pcount < n - add (n-pcount) particles. Any help is highly appreciated. Thanks,
  4. Transform glue dynamically. Glue to deforming objects

    Thanks guys
  5. Realistic Dynamic Fracturing with Bullet

    Exellent job so far. I still can't figure out some stuff. The idea with pin constraint, checking it with some criteria and determine stress area, is just awesome. But pin constraint wihout glue (as in your video) causes some instability to the pieces and pieces kind of dance, even when they don't collide. And for what you create glue constraints dynamically? Thnx in advance for reply.
  6. rigid body die on collision?

    After simulation, you can close your cup some way (some remodelling and maybe with polycap) so that you will have closed proxy of your cup an make sdf from that cap. Then you can check in vop sop or point wrangle your initial state if they are in that sdf or not and delete unneeded instances.
  7. Bullet - How to limit Velocities or exclude elements

    You would get clear answer if you posted your hip.
  8. Cloth Flag Procedural Point constraints

    Hi man! All you have to do is put "tick"s to the beginning and end of your expression "pointlist()". The reason is constraint point parameter eats string lists, but pointlist() returns lists of ints. flagCorrected.hip
  9. Houdini 13 Sneak Peek #3

    +1000 for that
  10. Houdini 13 Sneak Peek #3

    i expected that tiled voxels like vdb will be in dops in smoke solvers and flip solvers, i guess that there's no that feature as far as SESI haven't mentioned it in sneek peaks. It's a bit pity
  11. DOP Pyro Age Field?

    Create scalar field like age. match it with density (gas match field). Then advect it (gas advect field). Then in the post solve create gas field vop. It works similar to the vop sop. Just import your age field with parameter add iteger number and export it (again parameter). Back in sops, you can import this field and do anything you gonna do. Cheers
  12. Wood fracture techniques

    Hey guys, i watched some videos about rayfire. In fact it has great fracture tool. I like wood fracture. I believe in houdini it's possible to build same fx. I'm not talking about the fracture itself, but adding some detail to inside points. Here my setup, it works not bad, but have some problems. The setup is pretty simple. I did it in sop level but same thing could be done in shops. Would be great if someone could offer more relieble method. woodFracture.hip
  13. Wood fracture techniques

    thnx guys all for comments, i really appreciate it
  14. How to get Large scale foamy waves?

    Hey , check out the scene. Hope it'll help. The setup is not tweaked much, but hope the approach will be clear. foam_mist.hip
  15. emit smoke color from a texture

    If you advect Cd for certain amount of frames, the color will be very rough, so the good way is to add gas blur and blur the cd with small radius. I've just added this gas blur to your sim. You can compare. emitSmokeFromTexture02.hipnc
  16. gas explosion

    another interesting thing is if it's possible advect some noise field with high res after the sim so that to have an ability to mix it with heat. It's very hard to get noisy heat areas in massive sims.
  17. Hi there, for "true" motion blur i need subframes i guess, i simulated a simple smoke sim, then timewarped it. My cache was 100 frames, i warped it by 5 times so it's 20 frames. I've checked subframes, there is cache in subframes, but motion blur for with 5 geo samples is not working. I tried so much to get proper motion blur with vel field, but for fast movements that doesn't work. I would really appriciate your help. P.S If it's neccesery i can upload the scene file. But i think the problem is clear.
  18. Hi, i want to retime simulated smoke. I got some idea to do it dynamically. I have density and velocity fields. I'm trying to readvect the existing density with existing velocity with more substeps and changing the timescale of advect field microsolver. But i'm weak in microsolvers and can't realize the starting point. So if i import density and vel fields from cached sim, then make other density field and advect by cached vel with some different timescale and more substep, theoratically it should work. Would really appriciate any suggestion and help.
  19. Dynamic retiming of volume simulation

    That means that the advection occurs only on subframes, but on integer frames the advection timescale will be zero? Am i right? Actually i did so, almost i get some results, but only thing i can't realize how to interpolate cached density in subframes. In my setup i just import it with gas match field...My only problem is flicking because of the interpolation of sourcung cached density:(( Really appriciate your reply.
  20. Dynamic retiming of volume simulation

    I mean, e.g making if i want retime 3 times in dops, and advect cached density by cached vel, and advect it with some timescale value only in subframes and don't touch in frames and write $SF... i did something ($FF-floor($FF)) for timescale of advect fields the result is kinda retimed but there sum flicks:(
  21. Dynamic retiming of volume simulation

    You mean just import cached density and vel fields, then reimport it in new dop, advect cached vel with cached density? and 1/n is value of timescale in advect fields microsolver? would it be right way to advect in subframes? I tried with several ways but i can't catch the right values for subframes...

    Hey, you can scatter points into the volume, and project your image onto these points, then in volumeVop read back these points as pointcloud and create other vector field and transfer CD attrib to this vector field, then you can just make it kind a diffuse field. If your'e similutaing the smoke, you can advect this point and projected image will "swim" less
  23. Avoiding "Mushroom Cloud" smoke look

    Hi Eucalyptus, i've not looked at your scene, but increasing a padding on resize helps me to avoid the mushroom effect. Because of zero velocity outside the container smoke tends to "drag" causing this awfull effect So try to increase the container so that vel field could be advected far enough from density.
  24. Rendering Particles

    hey danylyon, just cache out your particles, read back and tick the point render option on geo node. Create your attribs like alpha, cd, pscale and etc and render. It should work!
  25. Dynamic retiming of volume simulation

    In sop level i could retime it definitely, but i'm sure readvecting with different timescale could retime in 10-15 times... thnx for info koen, i'll take a look