da_am

I'm trying to recreate an ultracentrifuge that seperates high density particles from low density particles. My current setup is two fluids with separate densities being emitted side by side to fill the container. Then once the container is fully filled I start up the "centrifuge", a pop axis force to spin everything at high speeds. The problem is it just acts as a blender and not a separator. I have a little divergence to pump up the fluid in the beginning but then it's removed. The densities are about 400 kg/m3 apart. I've tested fast and slower with different drags and settings but still just blends. Anyone else try something like this? Maybe I'm missing something important (more than likely, ha). Thanks! Update: kind of working now adding some mass, drag, and applying the rotation only to the low density particles. Faking it till it makes it I guess.

I figured it out! I basically used this pop vop to stick the points to the surface: https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=82040 Then the key part I was missing was to add an attribute for the points before putting them into the POP network. Then I used an Add to Delete Geometry but keep points (which I think got rid of the pop network). Added an Add to create the line and used that Point attribute I made before hand and voila, works as I expected it to. I hope what I just said makes sense and not a bunch of gibberish and houdini buzz words .

So I went with my original thought, which was to crawl the geo with particles and make a path from that using trails. Maybe I'm missing it but how do I turn trails into a curve that I can sweep? Is that a possibility? I can't figure it out. The trails are pretty close to what I want and they are fairly direct-able so I want to keep that route. Thanks in advance for helping a newb!

Still kind of working on this. Let's say I have a tunnel with random tubes branching off like a cave. Is there a way I could trace the contours of the cave with a curve that I sweep? I'm looking for something more artistic than a wireframe but procedural enough that I don't have to hand draw thousands of lines.

Oh, sorry, didn't see the hip at first. Thanks for that. I'm so new to Houdini, every time I open it I learn something (hopefully that continues to happen for a long while). I haven't touched splines really at all, just some pops and pyro stuff. Thanks!

Ha, that's great too! What did you use for the spline dynamics?

Great, thanks mestela! That actually led me to the draw curves tool. I'm not sure how I've never run across it but, while not procedural, seems like the fastest way to do what I need. Again, thanks for that!

Hi there, First time poster and fairly recent Houdini convert (half a year). I have a problem that I'm not sure how to tackle. I have a piece of geometry that I would like to wrap in string. Not necessarily overlapping and places where you can see the original geo (so not covered 100%). First I thought I should go the POP route but I can't figure out a way to crawl the object so the lines are somewhat neat. Painting where the lines will go is tedious and not really what I'm looking for. The POPs way would also mean I need to run the sim to get the object covered. I'm not sure if I have a lot of time to finish this look so I would love the quickest way to generate this on say 10 objects. Second I thought of using some sort of DOPs and attract the curves to the geo. This seems even messier and harder to control than the first route. Also I want to stay away from having to do this via a texture map to generate a displacement. I know I could do it fairly easily via a displacement map but at the same time I think this method would be the least accurate and not as procedural. If I can't do it procedurally I might as well hop back on C4D or Modo for the job and do it that way. I want to use the right tool for the job, you know? Any help would be super appreciated. I've fallen in love with Houdini and I am trying to use it in every project I do!

I'm working on a project with some crumpled paper and can't figure out how to recreate this effect. Also I can't build the tool that Rahul Narain and team came up with, arcsim. So I'm at a deadend. Have any of you run into a good way to work this out as an animation?