First stream! Sort of!
Added 2017-09-29 22:55:49 +0000 UTCNathan contacted me via Twitter, asking if I could help him with a particle droplet problem. The kids were quiet(ish) and I was keen to test the streaming, so thought we'd try a live session. I think it worked pretty well after a few teething issues.
Skip to about 7 mins in, and probably play it at double speed, runs for about 40 mins.
https://www.youtube.com/watch?v=jnqjhSBIFs4
Covers generating trails, using nage to generate a gradually decreasing pscale, then a ramp to shape, then a few different experiments in making the particles stick to the surface of an object, and have them fall off at a certain threshold.
Comments
Cheers mate, the end result is really helpful! That wrangling to get the particles to fall of the bottom is pure wizardry :)
Nathan Reynolds
2017-09-30 09:58:12 +0000 UTCOk, get the finished scene here: <a href="http://www.tokeru.com/cgwiki/index.php?title=File:Running_Droplets_me_v02.hip" rel="nofollow noopener" target="_blank">http://www.tokeru.com/cgwiki/index.php?title=File:Running_Droplets_me_v02.hip</a> The last 10 minutes covered a few things. The first was to let the particles fall off the bottom of the sphere. That's a wrangle within the trails popnet, where I lookup the closest point from the sphere, get the normal, and compare it to {0,-1,0}, (ie, falling straight down) with a dot product. If its within a certain threshold, I let it fall, otherwise I stick it to the surface. Next was more speed variation; I just used one of the preset vexpressions on the initial pop sim, which changes the noise amplitude randomly based on ptnum. Finally some particles were travelling too fast, those trails started to break up into dots. I restored bits of Nick's original setup in a slightly different way. I created a new attribute immediately after the original popnet, 'leaderid', and let the trails inherit it. I then use the add sop to create lines based on leaderid. Now I can resample to get more points, and feed that to the vdb nodes to generate the fat/thin trails.
Matt Estela
2017-09-29 23:48:12 +0000 UTC
