Jump to content

Adam Ferestad

Members
  • Content count

    238
  • Donations

    0.00 CAD 
  • Joined

  • Last visited

  • Days Won

    3

Adam Ferestad last won the day on May 16 2012

Adam Ferestad had the most liked content!

Community Reputation

6 Neutral

3 Followers

About Adam Ferestad

  • Rank
    Initiate
  • Birthday 02/04/1985

Contact Methods

  • Website URL
    http://www.AdamFerestad.com

Personal Information

  • Name
    Adam
  • Location
    Ohio

Recent Profile Visitors

3,810 profile views
  1. Differential curve growth

    Hey all, I'm trying a little experiment to see if I can combine differential growth with space colonization. I think I've done a pretty good job using a volume as the food. Each frame the wire eats some of the density volume around it, then I use the local density field as a multiplier on the movement, thus causing it to stop moving when it runs out of food. Obviously I had to shoot a pyro volume at it when I got it working. Still figuring out a few things with it and playing, but I figured Id share.
  2. Volumes inside geometry not rendering right.

    THANKS!!! From the few buckets that I have finished it looks like the fake caustics are doing the trick and actually producing the look that I want. The volumes + the shader are definitely going to be a pretty major performance hit, but I am planning on using this for a still for the time being, so it's not going to be too bad right now. Unfortunately for what I'm doing I need to have my volume limit at at least 1 anyway, so yeah.... sucks to be me, lol. Anyway, thank you so much. I am going to try the second approach you mentioned as having multiple solves for an issue is never a bad thing, and I'm sure there are instances where even with the performance hit it is the right way to go.
  3. I'm trying to render out a volume inside of a clear object and running into an odd materials glitch. To test I have created a box with a default glass principle shader and a VDB volume of the same box shrunk down inside the box which I have colored blue. Rendering with Mantra, if the volume is inside glass box, it loses all color, but outside keeps it. There is one other issue. I really want the volume to filter the light to color, so the shadow/rays coming out of the volume should be roughly the same color as the volume, as opposed to being black. volumeTest.hipnc
  4. Differential curve growth

    Yay!!! I did it. This one I actually love and will likely use myself for some stuff I have been thinking about. It uses a density volume to proportionally remove the travel distance at each stage, effectively making it stop progression in areas of high density. Currently I have a clamp on the values, so it only removes, but if you remove that, it should be straightforward enough to tweak it so you can make break it down like this: density = 0: no change 0 < density < 1: Progress is slowed density = 1: no progress density > 1: Reverses progress The reversal of progress might be tricky due to how I am calculating the travel direction, if there isn't travel, the vector ends up being the 0 vector, so you would need to get around the case where a stopped section begins to reverse. I would probably write another attribute that only changes if the length of the vector is above a certain threshold, so if density > 1 it can use that if it has an invalid vector for the direction. Adam Ferestad 180120_AD_DG[2DE]_00B-VolumeResist.hipnc
  5. Differential curve growth

    Looking at your file, I can think of several ways to do what you are looking for. The one I like the best is to create forces, vectors which are added in to affect the spread of the points. I put together an example of making your setup work their way around other meshes without going through them, I will probably fiddle with some more stuff with it. I do really like this setup. Similar setups to this can be done using volumes which act as resistance to growth through a density variable. I will fiddle with one of those next, but I wanted to get you something that might give you some ideas quickly when I saw the post. Adam Ferestad 180120_AD_DG[2DE]_00B-Avoid.hipnc
  6. I am trying to generate a field to control the light intensity of a volume light, and I'm having a little trouble figuring out how to go about it. I started off trying to take over emission properties on a material, but that didn't seem to be getting me anywhere, so I switched to trying to directly control the light_intensity parameter on the light. I know this should be possible, but the how is escaping me. I can always control the intensity based on color values, by setting them so the magnitude is over 1, but that feels very hacky and hasn't returned the results I would like. I want to be able to keep the color value and light intensity as independent as I can. Obviously I know I can't make a black smoke glow brightly, but I should be able to have white smoke that is lit up by the colored lit up volume. volumeLightFromField.hip
  7. Transferring attributes from particles to volumes?

    Thanks, I will take a look at them now. Yeah, the extra OTLs are for cloud farm use, makes it a lot easier to cache those vel fields and stuff when i can have 30 computers doing it at once. Hopefully I can see what's going on in these and stop banging my head against the wall with them.
  8. Transferring attributes from particles to volumes?

    I had done that to try to get it working, I had temperature there before and it didn't do anything. Trying it now to see if it will work. Also, that doesn't explain why the velocity field isn't populating. Or did it work from the Volume from Attrib? *edit* Yeah, I just fixed the names to all match and I still get a volume with a field size of [0 0 0], which means it isn't populating, on both the Volume Rasterize Points and the Volume from Attrib. I have to be missing something else.
  9. I am trying to get some temperature data that I have calculated on the output of a particle simulation to make it work with the pyro shader, but I can't seem to get it to transfer. I am using Volume Rasterize Points to get the particles into being a volume, which is working really well, but I can't seem to get anything but the density field filled. The node supposedly takes point attributes and fills a volume field with the data if it exists as both a field and a point attribute, which these do, but I keep coming up with empty fields. Failing that, I tried to brute force them over using Volume from Attribute, which I had successfully used elsewhere in the scene, but to no avail. Still giving me empty fields. This has started to become quite vexing, as I think it should be working how I have it setup, and it isn't. particleTest1.hip
  10. Advecting POPs with a Velocity Field???

    THANKS!!! that worked perfectly. Luckily I have access to a simulation farm, so I don't really mind it taking so long to look the way I want.
  11. I am trying to do a sort of Sci-Fi explosion, still deciding on the story behind it, but I know the look I am going for. I want to have an energy core going critical with energy masses spinning around it as if following magnetic field lines. I finally got my field lines working right and got them into a vel field, but now I can't figure out how to cause it to animate the particles. I plan to generally control the animation from this velocity field, so it is really important that I actually get it working. Any suggestions? I have attached the R&D file I am working with so you can see where I am with all of it. particleTest1.hip
  12. Purple parameter?

    ah, ok... that explains it. Thanks!
  13. Purple parameter?

    I am working with an asset that I purchased on Orbolt that looks like it was made in a previous version of Houdini to 16 and it has something weird going on which I don't know how to recreate. I am seeing a purple parm on a group node (old version) and I have no idea what that color means. A quick look reveals that $N should be the number of points-1, but the variable does not seem to be defined on the new node. I can get around it, but what does purple mean?
  14. Wrangle Node Recursion Substitute

    I saw someone mention the Solver SOP, but wouldn't that defeat the purpose of doing this in VEX and eliminate the parallel implementation that VEX brings? I also remember reading that Hscript supports it, as does Python, but do they support the parallel computing like VEX?
  15. Wrangle Node Recursion Substitute

    Ok, so I trying to work up some tests on sorting methods in Houdini and the one that I am playing with right now is supposed to parallelize well and I really want to test it using VEX, but apparently snippets don't currently support recursive algorithms. This is unfortunate because from what I have seen, several of the methods I want to play with are based on recursives and that basically knocks all of them out unless I can come up with an iterative method of implementing them. I am working on a Merge Sort found here: https://en.wikipedia.org/wiki/Merge_sort#Top-down_implementation, though looking at the code for the bottom up method reveals that it does not contain any recursion, so I will try to get that one up and running, though the problem remains what ways you all use to get around recursion with iteration for VEX snippets. I want to get some practice with fractal geometry, and those are basically all recursive, so it is going to become important soon.
×