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  1. Today
  2. Automatically fix mesh tunnels/holes

    It was also my idea my interpretation of what Konstantin described but i couldn't totally get, didn't dig enough into these part of Houdini... Could you confirm me it's the same idea? Also, there was a video from Sidefx and Unit Image which explains it if i remember correctly to automate their photogrammetry scanning pipeline.. ________________________________________________________________ Vincent Thomas (VFX and Art since 1998) Senior Env artist & Lighting & MattePainter & Creative Concepts http://fr.linkedin.com/in/vincentthomas
  3. Hi everyone, we meet a problem here. Our group are using Houdini to do the sand interaction effects, but we do the lighting in Maya. How could we do the transfer? For now, we just do the lighting in Houdini to try to match the lighting which we did in Maya. We use the Maya engine to import the sand particles from Houdini, but it occupied a lot of virtual memory. Is there anyone could help us ? We hope to find out how to solve this problem. Thanks a lot!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Looking forward to any suggestions!!!!!!
  4. How to drive smoke and blend shape

    Hi guys, I'm trying to remake this effect. I get the pyro source scatter by the Cd of the map, but dont know how to drive the pyro and blend between 2 shape. Hope u guys help me Many thanks
  5. Ring pyro burst

    Try the surface project, non-divergent, applied to a torus. http://www.tokeru.com/cgwiki/index.php?title=HoudiniDops#Pyro_stick_to_surface_with_project_non_divergent_sop
  6. Yesterday
  7. Ring pyro burst

    Your first sim looks pretty promising actually. You would get a lot closer to your desired initial poof using the combustion model rather than just straight smoke. Try using the first exploding points as a fuel and temp source for the combustion model and just limit your gas expansion so it doesn't get too out of control.
  8. Houdini 19 Wishlist

    Yeah I know, but by the time I am looking at the file name and realize it it going to take forever to open I have to cancel out of the open dialog, hit my hotkey for manual mode then bring up the open dialog again and open the hip file... definitely a lazy person request!
  9. Houdini 19 Wishlist

    I just switch to manual mode before opening a file that I need to be in manual mode. Is this kind of what you want?
  10. Simulating flip from bottle

    This is a great start! To answer a few of your questions - 1. Maya geo vs Houdini geo. Depends on a couple of things. Is the geo from maya, imported, processed, and then cached or are you just directly importing the geo from the FBX? FBX and alembic both sometimes bring in geo as packed geo, poly soups and this brings with it a number of problems. Houdini's geometry format is very efficient. You're going to have a lot quicker results using it. When you bring in your FBX, for your own sanity, never point your sim directly at that FBX. Import it, unpack it if necessary(usually only alembics are packed), convert it to poly, attribute clean it, trail it for velocities, and cache it as bgeo.sc 2. Scale is everything for flip. Small flip sims are always fun. On the one hand, using flip is intuitive and fun and, on the other hand, using flip for small scale simulations is kind of like using an excavator to do the work of a spade. Can you? yes, should you? It's going to be a lot of work and frustration because the tool is powerful but works best on medium to large scale simulations. Scaling flip simulations to the scale flip operates best at helps for sure BUT you wind up dealing with a lot of strange motion blur issues in the future when you scale things back down for your scene. It's not that this isn't something you can correct for just something to keep in mind because the amount you wind up scaling your object to bring it into flips happy place is .. completely arbitrary and the speed of your animation is again arbitrary. You can't just multiply by X percent because you're after all the cool inner swirly bits n such and bringing those down along with the speed at which your character swings it about means .. two very different numbers and splitting those velocities apart to scale them properly. As for volume loss, small quick moving objects and flip don't get along super well. The collision geometry often moves quickly enough that thin walled objects move through a fluid rather than push the fluid along with it which results in volume loss, see the particles flying out the backside of your bottle? There are a couple of things you can do to combat this. A. Make your collision volume with thicker than reasonable walls for such any thin walled object. B. Make sure your collision volume is calculated on a single frame, just once, and animated. That way it has proper collision velocity and the collision volume does not deform over time. C. Substeps of course. 3. For sourcing, I see no reason why this wouldn't work. The resolution of the volume responsible for the boolean is whats going to determine how exactly 100% of the bottle you fill but that seems fine. 4. Simfiles only caching points doesn't work because they contain the volumes the simulation uses to update the solver so you can pick back up in the middle of your sim at a random frame and move forward. If you just want the points you don't need to cache the simfiles. Just make sure your dopnet is only bringing in "flipobject1" "Geometry" and cache that to disk. Something to keep in mind, Flip does not recognize that the space the fluid is leaving creates a vacuum. Bubbling back up into the bottle is a big part of the pouring effect and something that I would be very interested in seeing here. Also always happy to look over the hip file anytime. Do include the geo files for the bottle if they're file references.
  11. This must be a really basic question, but I can't figure it out. For number of nodes in a network I typically just select all (Ctrl-A) and the status bar tells me how many nodes were copied. I tried the same trick on the Animation Editor hoping to see how many keyframes are in my curves but no bueno. How can I see how many keyframes are set on a channel?
  12. Ring pyro burst

    Another idea was using a cross product on volume gradient to get the motion: But again not there, maybe a pop curve force with orbit? is this the proper way to go for an explosion like this? Cheers
  13. Ring pyro burst

    Hey guys, I have to make a pyro sim of a ring turning into a burst, and then follow a curve and get sucked. First thing I'm trying to discover is how to get the explosion following this reference: My first thought is having particles rotating and use that as density source with some disturbance and dissipation, on my first RD I used some particles exploding outwards but the result isnt there: Any ideas to get to the explosion on the reference? and if there are ideas for the next step > follow curve and dissolve on left, more than welcome. Thanks!
  14. Cellular structures in fire

    opunhide Dop gasdsd to use the old solver. <------ You can get that look in Pyro with the right settings and shading.
  15. Cellular structures in fire

    I think there used to be a masterclass that discussed the DSD nodes, but it was since taken down. Here are the notes from that masterclass: http://slideplayer.com/slide/11347899/ (Edit: not saying that is required for whatever look in fire, I just like Houdini archaeology)
  16. Houdini 19 Wishlist

    I wish there was a checkbox to open a new HIP file with update set to manual, same as using -n at the command line. I also wish I could micro-tweak numerical parms with the up and down arrows like in Nuke. Ladder is cool, inertial scroll is cool (but only exists on trackpads) up and down arrows would be mega-cool. Also, let OpenGL ROP run in background so it doesn't feel left out from all the other ROPs. Also, match the shade of green used for a keyframe in the timeline with the shade of green on the "next keyframe" button. Don't know why that bugs me but it does!
  17. The example file for the vellum solver uses a pins group to animate a few of the points of a sheet and the solver takes over for the rest. Have you tried grouping a couple of the points and use them as animated pins?
  18. Trace equivalent

    So coming from a C#, javascript java background trying to master debugging simple VEX scripts. What would be the equivalent of a Trace or Debug.Log statement in VEX?
  19. Dynamically rotate geometry via VEX

    Thanks Henry. So a little more complicated than expected. So will try to integrate @Time into Thomas example to make dynamic.
  20. Houdini 19 Wishlist

    Set your editor to emacsclient, making sure that you've run M-x server-start in your existing emacs session.
  21. Cellular structures in fire

    I've never seen that solver before, I can't even get the node to show up with opunhide haha A lot of that kind of texture can be achieved with the settings in the pyro solver. I found this video really helpful https://youtu.be/fTIeGob0Wuo?t=1071 The video is a little old so I do believe the solver and shader have been updated since then but the parameters on the new nodes are far more intuitive and the things taught in this video translate pretty easily to the new shader and pyro solver.
  22. Creating bubbling lava

    I don't think you were importing the velocity into the simulation incorrectly but I can't say for sure because I couldn't get the solver to recognize the velocity properly. I could get it to show up in the visualization fields but it wouldn't interact properly. I couldn't tell if it was a version issue or something to do with some changes you had made to the setup, hence me rebuilding that part of the network. The velocity of your bubble was coming from the particle to which it copied each sphere. So the velocity of each point on the bubble was exactly the same (0,1,0) meaning no outward movement was taken into account. When you animate the sphere, for example with a mountain, that doesn't change the velocity attribute, it only changes the position of each point. To add the motion that mountain gives you to the points you need to recalculate your velocity using trail.
  23. Dynamically rotate geometry via VEX

    Setting N to P would only be a good idea if you're rotating a unit sphere. Otherwise your normals aren't going to be normalized, and may possibly make no sense when rendering or displaying. Thomas is correct in that you should update the normals as well as P... multiplying by the same matrix (and possibly normalizing afterwards to be safe) is a good choice. The Deformation Wrangle SOP will update normals and other vector attributes automatically, if you want to give that node a shot... it requires slightly different syntax.
  24. Cellular structures in fire

    Hello all, I'm working on a fire shot and am looking to get a cellular effect like many actual fires: The results I get from the Pyro solver are more like regular smoke / fluid behavior, ie very streaky and a bit blurry. It seems like the old DSD solver was intended to generate exactly these structures, but I can't get it to work without any example files and would also rather get a similar result in Pyro. (Paper the DSD solver was based on, apparently: http://physbam.stanford.edu/~fedkiw/papers/stanford2007-02.pdf) Is this just a matter of tweaking Shredding and Gas Release to do the right thing? Or increasing the resolution to a very high level? Thank you!
  25. Dynamically rotate geometry via VEX

    Thanks!! I figured something to do with normals. But in my case would it simply be adding? @N=@P; Another thing I was wondering is if it is possible to determine the current RPM value using my above VEX code?
  26. Hi everyone, I have a question How can I use animated object as Vellum Source to make it works with Vellum Solver DOPs? (not SOPs) This is my hip file As you can see, the Vellum dopnet processes with only the first frame of the object animated_vellum_dop.hip
  27. Flickering colours in slow Coloured Smoke

    Hi all! Has anyone have a solution for this? I'm stuck with the same problem; when I try to up-res my smoke sim via shelf, I'm loosing the color and I can't find a way to bring it back.. :\
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