midicon Posted September 26, 2015 Share Posted September 26, 2015 I have a geo cashed arm. in polys. I converted it to a NURBS surface. And I want to have particles (primary a fluid) traverse the arm. to try to make a terminator liquid metal type effect. but when I try to use the creep it seems to only want to use one poly (or patch not that its converted). any one have any suggestions what I'm doing wrong? I have attached a file and a bgeo of the arm, for anyone to have look at. Thanks for your help CreepTest.rar Quote Link to comment Share on other sites More sharing options...
kungFu Posted September 28, 2015 Share Posted September 28, 2015 Parametric surfaces have their own UV from the way they are built. This is different than the UV created by "UVing" something. Polygons will default to a UV of 0 to 1 per poly, and converting a poly to a NURB doesn't copy over the parametric UV info that creep needs. A brief google revealed these: https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=33159 http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=16877&highlight=&sid=fda82fd7786792731cd0ff8531af0837 or possibly a "roll your own creep" (changing the space your effect is happening in) http://www.andyboyd3d.com/siggraph_talk/img26.html Not really an answer, but might help. -james S. Quote Link to comment Share on other sites More sharing options...
Farmfield Posted September 28, 2015 Share Posted September 28, 2015 (edited) For having stuff move around on/in/under surfaces, my personal favorite is converting your mesh to a volume and sampling the gradient to get things moving where I want it to. If you haven't messed with it before, you got the gradient from volume lookups using a POP VOP and it'll give you a vector pointing in the normal direction with a 0-value on the surface with negative values invard and positive outwards, and you just use that for controlling particles/fluids on the surface - or under it. Edited September 28, 2015 by Farmfield Quote Link to comment Share on other sites More sharing options...
Hamp Posted September 29, 2015 Share Posted September 29, 2015 (edited) @Johnny Farmfield I've tried to accomplish this but never quite found the set-up to do what I want. Do you possibly have a simple .hip example of this? Would be awesome. Edited September 29, 2015 by Hamp Quote Link to comment Share on other sites More sharing options...
Farmfield Posted September 29, 2015 Share Posted September 29, 2015 @Johnny Farmfield I've tried to accomplish this but never quite found the set-up to do what I want. Do you possibly have a simple .hip example of this? Would be awesome. I looked through mu stuff and I didn't have anything fitting so I created this setup now. It's a mess, hehe, but it's in the right direction at least. I'm not envious of you having to figure out what the hell I did, why and tweak it for 2 weeks until it's usable. Quote Link to comment Share on other sites More sharing options...
Farmfield Posted September 29, 2015 Share Posted September 29, 2015 (edited) @Johnny Farmfield I've tried to accomplish this but never quite found the set-up to do what I want. Do you possibly have a simple .hip example of this? Would be awesome. I looked through mu stuff and I didn't have anything fitting so I created this setup, now you just have to figure out what the hell I did, why and tweak it for 2 weeks until it looks good. EDIT: LOL - and the scenefile I posted actually isn't working as it should, damn, I'm gonna sort it out and repost it. Edited September 29, 2015 by Farmfield Quote Link to comment Share on other sites More sharing options...
Hamp Posted September 30, 2015 Share Posted September 30, 2015 Thanks for giving it a shot Quote Link to comment Share on other sites More sharing options...
Farmfield Posted September 30, 2015 Share Posted September 30, 2015 (edited) Thanks for giving it a shot Och först nu ser jag att du är Svensk. ^ Swedish insult aimed at anyone reading this! Anyways, I got it going with particles on a surface using the gradient and I'm gonna set it up with fluids again now, but I thought I'd post the particle scene file as that's pretty telling on how it works. arm.pop.setup.hiplc Edited September 30, 2015 by Farmfield Quote Link to comment Share on other sites More sharing options...
Hamp Posted September 30, 2015 Share Posted September 30, 2015 (edited) Jodå, tackar ^ Swedish insult aimed at anyone reading this! Thanks a lot! It'll be interesting to see where I went wrong in my attempts, will keep you posted and hope to repay the favor some day. *Edit* Just opened it quickly, will have a more thorough look tonight - thanks for the nice text descriptions. Might not have to dig too many weeks to understand. Edited September 30, 2015 by Hamp Quote Link to comment Share on other sites More sharing options...
Farmfield Posted September 30, 2015 Share Posted September 30, 2015 (edited) So I had this up and running with a fluid sim today but I didn't come to a result I'm eager to share, hehe, I'm only willing to shame myself so far in a forum like this... And the the problem isn't getting it working - you set it up exactly as in the particle sim, though you pipe the POP VOP into the 2nd port of the fluid solver, you can just copy paste it as is as a starting point - the problem is making it look good, and that's tough, fluids aren't the easiest to make took "real" when you start messing with custom forces... Edited September 30, 2015 by Farmfield Quote Link to comment Share on other sites More sharing options...
Hamp Posted October 9, 2015 Share Posted October 9, 2015 Thanks once again! I'm getting hang of it now However, is it possible in some way to keep the particles from leaving the surface. Kind of like an attractor? Or maybe this is the wrong approach for something like that? Quote Link to comment Share on other sites More sharing options...
Farmfield Posted October 9, 2015 Share Posted October 9, 2015 Yes. I rewired it like this, forcing the position instead of piping it into the force. arm.pop.setup.v2.hiplc Quote Link to comment Share on other sites More sharing options...
Hamp Posted October 9, 2015 Share Posted October 9, 2015 (edited) Hah! This is what I have tried to get right before, but failed. I mistakenly figured that P would just snap points. What a joy! So much more fun than balancing goal weights in Maya Edited October 9, 2015 by Hamp Quote Link to comment Share on other sites More sharing options...
Farmfield Posted October 9, 2015 Share Posted October 9, 2015 When you get to the point where you stop seeing stuff like anything else than vectors, it's such an eye opener. So I have a point and I want to move it to a position, in reality that means I have a vector and I need to move it to another vector, then you just have to figure out the math and do it. Quote Link to comment Share on other sites More sharing options...
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