Category: hou-general

okay i got it.

in order to force houdini to use its own internal openCL dll, you need to add the following key to your environment:
`HOUDINI_USE_HFS_OCL = 1`

you can also use primuvconvert to move between arc length measurements (UNITLEN -> UNIT for example)

summint like that…

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20195401/08/19/resampleCurveu_primuvconvert.hiplc

woo: github.com/wirginiaromanowska/Notes_On_Things

oh one other aspect, do your noise lookup on the surface, so use VDB Analysis to make a Closest Point field that you use for noise lookup

this is the basic idea

it’s also helpful to use curvature to modulate it when applying multiple times

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20185411/07/18/starterPuff.hip

using this btw: www.desmos.com/calculator

Hey @kevbot9000, set the external browser in your .env file “`HOUDINI_EXTERNAL_HELP_BROWSER = 1“` it’s way faster

Wow I couldn’t even understand it in the first few minutes

I made a small video to introduce the pop fluid node in Houdini 17, with the source file for the small test I did few days ago, hope this is not annoying to share here 😳 https://vimeo.com/295491505

TLDR: Pop fluid node is based on PBD fluid which is partially based on XSPH with some fundamental difference, but it’s not part of the vellum solver, not yet. The Pop Fluid node contains a PBD fluid solver, which is based on the paper by Miles Macklin and Mattias Muller in 2013 from NVIDIA. The difference between traditional SPH and PBD fluid is, SPH uses a kernel to “smooth out” essential attributes around every particle, whose neighbors are within the smoothing radius, so it tends to get unstable when nearby density is inconsistent and requires lots of substeps to solve the problem, very costly. PBD fluid (which contains parts of the XSPH) tries to solve this problem by bringing the pressure solving stage(where the density problem happens) into the PBD framework, which uses constraints to solve problems (constraints avoids). Basically, a new type of constraint which is based on the positions of each particle, rather than a smoothing kernel, is introduced to help to get a more consistent density with iterations(by updating positions directly within each iteration, not accumulating pressure throughout all the substeps and then apply forces).

feel free to correct me if I am wrong

my fave for doing extract transform in SOPs is this, which gets the full 4@ including scale and possibly skew

instead of using the first 3 points of the first prim you can use first/middle/last points of the full mesh if you have worries about there being some non-affine local deformation

Here’s a script to flipbook stuff out, and then mp4 it: “`python import toolutils import os import subprocess
def flip(): scene_viewer = toolutils.sceneViewer() flipbook_options = scene_viewer.flipbookSettings().stash() flipbook_options.frameRange( (hou.playbar.frameRange()[0],hou.playbar.frameRange()[1]) ) output = hou.hscriptExpandString(‘$HIP/flipbook/$HIPNAME/$HIPNAME.f.png’).replace(‘.f.’,’.$F4.’) if not os.path.exists(os.path.split(output)[0]): os.makedirs(os.path.split(output)[0]) flipbook_options.output(output) scene_viewer.flipbook(scene_viewer.curViewport(), flipbook_options) ffImage = output.replace(‘$F4′,’%04d’) movPath = output.replace(‘$F4.png’,’mp4′) proc = subprocess.Popen(r’ffmpeg -y -start_number %s -i “%s” -c:v libx264 -preset slow -pix_fmt yuv420p -crf 22 -c:a copy %s’ %(hou.playbar.frameRange()[0],ffImage,movPath)) proc.communicate() proc.wait() print(‘Done’) “`

hmmm, that’s maybe a bit spammy, sorry