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Showing most liked content on 05/09/2020 in all areas

  1. 2 points
  2. 1 point
    I have used this setup on a number of projects and thought I would share. Basically, it is a simple setup that uses the wire deformer and hair system to animate geometry. I used to do this all the time back in Maya using Shave and a haircut, and was surprised that there isn't a more straightforward method to do this kind of effect in Houdini. This is especially useful when you need to add flowers or other kinds of detailed grass to an existing grassy field that has wind blowing through it. grass_example.hip
  3. 1 point
    Yeah I've dived into it quite a bit since my original reply and I'm really happy with it as a solution to large expanses of meadow grass. I'd not had reason to touch the hair/fur system before but I can see how powerful it is for this sort of thing. I'm planning on mixing your method above with un-instanced 'normal' hair as shaded grass to lighten to load a bit. Thanks for the starting point!
  4. 1 point
    images are generally bad at conveying this sort of issues, anyway here is a file with 2 methods - uv layout, which can use i@udim attribute to lay islands out into udims, but changes incoming layout within uv tile - however if you are happy with layout within uv tile you can just offset uv islands into particular udims using simple vertex wrangle: int udim = prim(0, "udim", @primnum); v@uv %= 1; v@uv.x += (udim - 1001) % 10; v@uv.y += floor((udim - 1001) / 10); obviously the udim has to have the same value per the whole island ts_place_uvs_to_udims.hip
  5. 1 point
    by default the gas resize only resize legacy field of the pyro solver like density, temperature. If you are adding a personnal field you need to tell houdini to resize it as well. Either it will be a 1x1x1 cube. The +1 frame starts to resize the sim after the sourcing. So you source first then you resize. Either your fields will collapse because there is no density in the simulation.
  6. 1 point
    Try repulsion 100 or lower. Should help.
  7. 1 point
    Hey f1480187 Beautiful solution using advect points. Checking the wrangle nodes in your scene, some of the code lines don't make sense to me. That said, would you know where i can grab more info about how you came up with that solution?
  8. 1 point
    @caskal here is another set up using a point vop and curl noise, giving you some more control over the noise on the surface. curlshiznat.hiplc
  9. 1 point
    @f1480187 Finally got (the simple setup lol) A question about the simplest point wrangle // Project onto a tangent plane. @v = @v - @N * dot(@v, @N); //@v = normalize(@v); Googled tangent and readed its the rect that touches a curve in a certain point (as I said math is not my fort), is this what this snippet is doing? Why we have to rest the velocity by the normal? and what does the "dot(@v,@N)" stuff does? Understanding this first setup will be enough for now, I get some parts of the other point wrangle, but I better start reading more the tokeru cgwiki, I hate coding, but its needed for achieve the results Im looking for, plus is multithreaded. Btw, how old are you?
  10. 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