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Showing most liked content on 07/15/2017 in all areas

  1. 4 points
    Tried centroid? Laziest way you can write it is centroid(0,0), centroid(0,1), centroid(0,2) for x y z. The tooltip that pops up says use a string for geo and then D_X, D_Y and D_Z but you can drop the string for 0 and the rest for 0 1 2.
  2. 1 point
    Hey community, first of all thanks everybody for all the help, couldn't have learned this soft without this forum. Here is some art I did with Houdini, feedback is always welcome.
  3. 1 point
    Andy Lomas' work on cellular growth has been really inspiring. He implemented all his code to run on GPUs. I was wondering how hard it would be to do this natively in Houdini. After some contortions, this is what I ended up with:
  4. 1 point
  5. 1 point
    Maybe you can try with Vex attributes: @cent.x ; @cent.y ; @cent.z instead of $CEX ; $CEY ; $CEZ I hope this will help.
  6. 1 point
    Ahh bugger sorry chap I thought I'd covered that already. Rushed it out on a Friday between usual tasks - Lemme have another look.
  7. 1 point
    I like to connect trailed points (or particles) then polywire those curves, to get smooth emission from fast geometry. Something like this, but I'll have velocities on the geometry, and noise it up sometimes to break up the shapes a bit further. When going this route, sometimes you have to dial down how much density is emitted on each frame; if there is a lot of overlap, it can dump too much density and cause a lot of expansion and slowness. fast emitter.hipnc
  8. 1 point
    That looks great. Thanks for sharing. When you look at the paper from Lomas, he also experimented with reaction-diffusion as well as photosensitivity, e.g. nutrients get produced where sunlight reaches.
  9. 1 point
    "Morpho" Played with the file from Activate today, replacing the random nutrition distribution with a noise function for a more diverse structure and rendered with Octane... Cheers, Tom
  10. 1 point
    Exactly. In the example below the position and rotation constraints have different condofs... walkerc.hipnc
  11. 1 point
    I finally got around to cleaning up the hip file and have attached it. If you end up using this, please let me know how it's going and share a pointer to your work. The major challenge with writing this in VEX was that VEX does not offer any of the canonical data structures one would use to efficiently implement this. For me, the simulation ends up running out of memory around a 1000 frames. As I am novice to Houdini, I would also appreciate any feedback and comments you might have if you end up taking a look. Enjoy? :-) MorphogensisInVex.hiplc
  12. 1 point
    Use VDB point advection to output geometry. You need to compute a velocity vector, it's up to you. For example, just a curl noise (first image) is a good starting point, as well as cross product of @N and position delta using point cloud (second image, some noise applied also). It may be anything you could imagine, from fluid trails to volume thickness. curlypig.hipnc
  13. 1 point
    Looks like you can do it using the Partition SOP, here's a quick file thrown together to show it working group_polygon_islands.hipnc
  14. 1 point
    I couldn't find any good ways of doing procedural edge loops (let me know if there is a good way!) so I wanted to see if I could do it in VEX - also as a bit of an exercise in VEX. I got pretty close; it seems to do quads fairly well - it doesn't do tris or ngons currently but i'm sure that could be implemented. I'm sure there will be issues with it not carrying across attributes etc. I haven't really done much testing, but i'd like to see if this is interesting or useful to anyone. Or if anyone can improve it that would be good too! (its pretty messy so i'm sure it could be made more efficient at least) File is attached edge_loop_02.hipnc
  15. 1 point
    The rest field is basically a field storing the initial positions. For a fluid sim, we can use a rest field for noise lookups in the shader to add apparent detail to your sims at render time. The rest field is advected along with the fluid and therefore the noise can look like it's moving with the fluid when you render it. Further, in houdini the default is to have 'dual rest fields' so that your noise doesn't get too streaky. You have two positions for looking up noise values that are reset every x number of frames, they offset in time from one another so that when one rest field is reset, the other is in full swing, then vice versa. The noise crossfades into the other so that when you add noise to your sim, you get a smoother, and not as streaky effect. Edit: not much in the way of tutorials for this I think. I have a file set up here that breaks up the rest field setup on it's own and I apply it to a flip sim instead. It may help you get the idea by seeing it on a mesh instead of a pyro sim.. http://fx-td.com/?p=329