sebkaine Posted June 5, 2015 Share Posted June 5, 2015 (edited) Hi Guys, I would like to know what would be the fastest / best approach to advect pop on a pyro vel field. I want that the advection happen in the same time as the pyro sim. i find that using multisolver looks to be the cleanest approach but i'm not sure ? i have assemble a simple scene that works smoothly but i get an error signal on my pyro nodes, so i would like to get some expert pov to know what i am doing wrong ! Thanks for your time Cheers E advection.hip Edited June 5, 2015 by sebkaine 1 Quote Link to comment Share on other sites More sharing options...
H2O Posted June 5, 2015 Share Posted June 5, 2015 Hi Manu, Hope you're fine since last year I started to work with an advection system really simple a few weeks ago. Take a look at it and tell me what you think! Cheers advection_method_02.hip 1 Quote Link to comment Share on other sites More sharing options...
sebkaine Posted June 5, 2015 Author Share Posted June 5, 2015 (edited) Hi Paul ! Hope you're doing well dude ! Thanks for your help ! The fact of having 2 dop is a cool method, but for this one i was trying to get all the DOP tree inside one DOP network instead of 2. I find it more straightforward for playing with parameters. that's why i find using multisolver could be a cool approach , i would be curious to know other trick to do this in order to do a pro/cons of each approach ! Thanks again for your help ! Edited June 5, 2015 by sebkaine Quote Link to comment Share on other sites More sharing options...
Skybar Posted June 5, 2015 Share Posted June 5, 2015 Take a look at the Mist shelftool. Simplified it essentially plugs a POP Source DOP into a Gas Advect DOP, and then plug that into the Advection input of the Pyro solver. 1 Quote Link to comment Share on other sites More sharing options...
rtep Posted June 5, 2015 Share Posted June 5, 2015 Howdy, Here's a slightly different multisolver setup that doesn't seem to be getting any errors. Although I think yours are just warnings and they don't seem to mess up anything. simplepyropopadvect.hip And here's another example I was working on from a different post http://forums.odforce.net/topic/22809-how-to-retain-advected-velocity-of-particles-as-new-particles-are-created/ It's a similar concept to what your working on and I think this file could have some cool uses. particlestest_v03.hip Quote Link to comment Share on other sites More sharing options...
sebkaine Posted June 5, 2015 Author Share Posted June 5, 2015 (edited) thanks for your reply guys ! i'm gonna check this in depth ! very cool hip Richard ! thx for sharing ... By the way i still have the same warnings on Pyro solver with your exemple ... I don't know what is the origin of this ... and how to fix this ? i will keep testing this to see what approach i like the most ... Edited June 5, 2015 by sebkaine Quote Link to comment Share on other sites More sharing options...
sebkaine Posted June 5, 2015 Author Share Posted June 5, 2015 (edited) well i have compile all the methods i know , and for the moment David methods is the simplest one and maybe the most efficient ? it's also the only who doesn't give me error message on pyro solver ... advection_versus.hip Edited June 5, 2015 by sebkaine 2 Quote Link to comment Share on other sites More sharing options...
magneto Posted June 5, 2015 Share Posted June 5, 2015 Which one is David's method? #4? Because that's the most familiar particle advection for me too and the simplest. The other methods seem more convoluted, but I am not sure if they have any advantage for method #4. Quote Link to comment Share on other sites More sharing options...
sebkaine Posted June 5, 2015 Author Share Posted June 5, 2015 (edited) yes David Method is #4 ! like you i would be curious to hear some expert pov on +/- of each methods ! Edited June 5, 2015 by sebkaine 1 Quote Link to comment Share on other sites More sharing options...
magneto Posted June 5, 2015 Share Posted June 5, 2015 I see, I wonder if gridless advection is related to this topic? I didn't get around to reading that thread so Gas Advect might as well be doing that too. Quote Link to comment Share on other sites More sharing options...
Skybar Posted June 5, 2015 Share Posted June 5, 2015 It depends on what you are after of course, but you could just tweak and sim the Pyro until you feel satisfied - cache that out - and then in a seperate POP Sim use "POP Advect by Volumes". This would allow you to tweak the particles seperately, adding additional forces and whatnot - without having to constantly re-sim the Pyro which you are already happy with. 1 Quote Link to comment Share on other sites More sharing options...
Solitude Posted June 6, 2015 Share Posted June 6, 2015 (edited) It depends on what you are after of course, but you could just tweak and sim the Pyro until you feel satisfied - cache that out - and then in a seperate POP Sim use "POP Advect by Volumes". This would allow you to tweak the particles seperately, adding additional forces and whatnot - without having to constantly re-sim the Pyro which you are already happy with. I completely agree with this. Get the pyro sim how you want it, save it to disk, do the particles in their own pass. It'll likely be a good bit faster not having to deal with the pyro sim at the same time as well. In 13 I used to use the gas advect microsolver to advect points as it was more accurate to the pyro sim. The new pop advect by volumes in 14 now has more advection methods (such as the trace method, which is the same as pyro's default), and mimics the gas advect node. It's much better than before, and both are good options. I just opened the file -- if you look at Method 2, switch the advection type to trace. It might not look like a big difference, but doing a simple velocity sample and apply (single step advection) won't be accurate, especially if you have a strong emitter. However, the trace method will more or less 'trace' it's way through the field, moving voxel by voxel and resampling as it goes based on the 'cfl' -- it will result in a sim that matches the pyro much better. You may have to lower the cfl below 1 just a bit to make it work better I noticed a while back. The cfl kind of controls how big of a step it's allowed to take. The advect by volumes is vex, so it's fast too. I'm sure the gas advect is also multithreaded, but I haven't done any benchmarks. Another awesome thing about houdini -- check out $HFS\houdini\vex\include\advect.h if you want to see the code for how the new advect by volumes stuff works. Edited June 6, 2015 by Solitude 2 Quote Link to comment Share on other sites More sharing options...
sebkaine Posted June 6, 2015 Author Share Posted June 6, 2015 thanks a lot for all your feedback guys , i think i have now enough material to play with. i have pack a hip that sum up things as simple as possible. Cheers E advect_ok.hip 1 Quote Link to comment Share on other sites More sharing options...
Shinjipierre Posted June 6, 2015 Share Posted June 6, 2015 Mmm, here's another way to advect points which is probably the fastest, tested it on a shot with around 20million points for 750 frames. But, that's not in dops... although there may be a way of doing it in a sop solver advect_ok (1).hipnc 1 Quote Link to comment Share on other sites More sharing options...
Skybar Posted June 6, 2015 Share Posted June 6, 2015 Mmm, here's another way to advect points which is probably the fastest, tested it on a shot with around 20million points for 750 frames. But, that's not in dops... although there may be a way of doing it in a sop solver Well, the Solver SOP is just a neat package for a DopNet + Sop Solver. So you are already doing it with Dops sort of. Quote Link to comment Share on other sites More sharing options...
sebkaine Posted June 7, 2015 Author Share Posted June 7, 2015 Thanks for your help Remi ! hope you're doing well in BC ! That's a cool tricks to use vdb advect i keep this one in my toolbag. Quote Link to comment Share on other sites More sharing options...
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