dyei nightmare Posted February 26, 2010 Share Posted February 26, 2010 (edited) after watching this video from gnomon, i was wondering if the growing cotton candy effect that you cant see there, is it posible to do it in houdini... yeah, with iso ofset and volume tools but, the cotton candy is more dense than volumes, at least what i ve seen... but maybe tweaking some shaders?? i saw something like the effect from some guy that did something similiar, but again, volumes dont look as "dense" as cotton candy looks. anyone has some ideas, or examples of this effect in houdini? this is an exercise from other guy in some thread i saw long time ago, but the look is more like gas, not cotton, so, how could it be done to apear more solid, more "cottonish" more like cotton candy? download here: http://dyei.sabotage.ws/cottonwool_440.hipnc Edited February 26, 2010 by dyei nightmare 1 Quote Link to comment Share on other sites More sharing options...
LFX Posted February 26, 2010 Share Posted February 26, 2010 I would say it's some sort of foam, and it's played backwards. Quote Link to comment Share on other sites More sharing options...
dyei nightmare Posted February 26, 2010 Author Share Posted February 26, 2010 (edited) I would say it's some sort of foam, and it's played backwards. yeah we know that, but, the point is, how could it be done in houdini... im doing some tests and i am aproaching the look with volumecloud shader Edited February 26, 2010 by dyei nightmare Quote Link to comment Share on other sites More sharing options...
pclaes Posted February 26, 2010 Share Posted February 26, 2010 Very cool example . Perhaps with fur. As that can generate very densy hairy looking structures. On top of that the fur is a dso, which generates the geometry at rendertime, allowing you to add huge amounts of detail. The droplets would be done with particles/metaballs. With fur you can deform the furm with your shaders, so you can animate it (deformation). Or instancing lines (little clusters of lines like little cotton balls) onto pointclouds generated from points scattered in a volume. In Eetu's lab thread he advects particles by the inverse gradient of a volume: If you keep doing that long enough and set your line to be thin and a bit transparent you will get puffy wire shapes (you might have to kill particles that go to far outside the volume, and spawn a few new ones occasionally). Quote Link to comment Share on other sites More sharing options...
sam.h Posted February 26, 2010 Share Posted February 26, 2010 something like this? Use the contrast in the shader to make the volume 'edge' more solid ... fluffyMcFlufferton.hipnc Quote Link to comment Share on other sites More sharing options...
mightcouldb1 Posted February 27, 2010 Share Posted February 27, 2010 I worked on this video. It was cotton candy melted and playing backwards... I wanted to use Houdini for this, but I didn't know it at the time. We ended up using painted stuff... Anyway, Sam's example is cool! Quote Link to comment Share on other sites More sharing options...
dyei nightmare Posted February 28, 2010 Author Share Posted February 28, 2010 (edited) wow thats an exelent exercise in cotton creation, sam, congratulations, and thanks petter claes you give me some ideas, and your link was very usefull, and congrats mightcouldb for particpating in that video, thanks to all, i will be making some tests Edited February 28, 2010 by dyei nightmare Quote Link to comment Share on other sites More sharing options...
MENOZ Posted March 20, 2010 Share Posted March 20, 2010 (edited) how would you make the cotton candy effect? using fur? yes, the eetu way could be ok for a general shape, but a cotton andy has millions of hairs, and generate them in viewport one by one using curves it's not possible. maybe using fur could be the way to go.. anyway I find rendering fur in houdini is terribly slow, so I didn't investigated on how exactly the fur cvex node works . I think it needs a surface for grow curves from, I don't think it can generate curves from generic curves shapes. How can I do to calculate the light dispersion inside of the puff?? point clouds probably.. or depth map from volume? the volumetric way could be good for far distances i think, but it laks of the "surface" details. Anyone has ever tried to replicate cotton candy? MAYBE the cluster_this otl could help, but still I can't make it works Edited March 20, 2010 by MENOZ Quote Link to comment Share on other sites More sharing options...
pclaes Posted March 21, 2010 Share Posted March 21, 2010 The clusterThis would probably help, but you can probably get quite far by instancing delayed loads. I'll give it a go. regarding the color densities you can quite easily do something like this with pointclouds: http://thiagocosta.net/?p=136 Quote Link to comment Share on other sites More sharing options...
pclaes Posted March 22, 2010 Share Posted March 22, 2010 tomorrow I'll kick off the animation for rendering. It is indeed kinda slow, because of shadow maps mainly... and you need those to get that depth in there. The animation needs more work, but the look is getting closer. Have fun learning from the hip, there's lots of stuff to explore . cotton_puff_05.hipnc 2 Quote Link to comment Share on other sites More sharing options...
dyei nightmare Posted May 26, 2010 Author Share Posted May 26, 2010 tomorrow I'll kick off the animation for rendering. It is indeed kinda slow, because of shadow maps mainly... and you need those to get that depth in there. The animation needs more work, but the look is getting closer. Have fun learning from the hip, there's lots of stuff to explore . thanks a lot peter claes, you are teh man, but i have a little problem, i cant get it to work, i mean when i render it, it just looks like is generating some geometry in some non existant folder in my machine, then... at the end the render is just black... just an alpha channel... why could this happen? what i need to do to be able to render it.. somebody could help? Quote Link to comment Share on other sites More sharing options...
pclaes Posted May 26, 2010 Share Posted May 26, 2010 You need to make sure you have some of those caches rendered to disk before rendering your image. Also you'll have to adjust the paths to match your directory structure. It's been a while since I had a look at this scene. Since then my computer broke and got fixed again . I'll see if I can dig up that animation too. Although I just moved house and haven't got internet yet. Quote Link to comment Share on other sites More sharing options...
barad_dur Posted June 10, 2010 Share Posted June 10, 2010 sam.h, I was just wondering what the vopcop2gen1 is doing. It looks like a cellular pattern that is used to adjust density in the cloud but I can't find where it is being refferenced for usage. Is the vopcop output being used at all? I was just really interested in what was going on with that. David. something like this? Use the contrast in the shader to make the volume 'edge' more solid ... Quote Link to comment Share on other sites More sharing options...
dyei nightmare Posted February 25, 2012 Author Share Posted February 25, 2012 (edited) hi, peter after almost one year, im returning to this subject, and in houdini 5.0.81 the loading of bgeos, and the render take soo long, is this normal? should this take so long? like half hour of this: ding geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:166 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:74 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:260 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:225 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:190 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:292 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:177 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:210 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:27 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:101 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:44 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:145 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo file procedural: /obj/cotton_puff_load_1:/obj/instance_render:263 loading geometry E:/d/houdini/DELAYED LOAD/ca/cotton_puff_1_1.bgeo Edited February 25, 2012 by dyei nightmare Quote Link to comment Share on other sites More sharing options...
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