Macha Posted May 12, 2012 Share Posted May 12, 2012 (edited) Does anybody know how to add ids to flipfluid particles in H12. I tried all sorts but can't get it to work stably. Where are the particles genereated??? Even a non-than-perfect id would be OK. Edited May 12, 2012 by Macha Quote Link to comment Share on other sites More sharing options...
eetu Posted May 12, 2012 Share Posted May 12, 2012 A slide modification to the setup from Flip Viscosity Driven by Age. Check the added AttribCreate in /obj/AutoDopNetwork/source_surface_from_sphere_object1/source_particles/attribcreate_ID It will start to produce duplicate IDs if particles are ever removed, though. If the IDs do not need to be consecutive, I guess you could multiply them by $F*10000000 to get rid of the duplicates ee_flip_id_v002.hip 1 Quote Link to comment Share on other sites More sharing options...
Annon Posted May 12, 2012 Share Posted May 12, 2012 I'm pretty sure if you add a popsolver to the mix (fourth input) then it starts to add ID's. This is how I've done it, as well as age etc... Quote Link to comment Share on other sites More sharing options...
Macha Posted May 12, 2012 Author Share Posted May 12, 2012 Hm. I'll try it. I added my own sopsolver in there before but couldn't get good results, mostly because particles are born and die and its hard to find the frame where they are born (I tried to find the birthframe by putting them in a group and comparing if they already are in it, but it's not stable somehow). Quote Link to comment Share on other sites More sharing options...
mawi Posted May 12, 2012 Share Posted May 12, 2012 (edited) Hm. I'll try it. I added my own sopsolver in there before but couldn't get good results, mostly because particles are born and die and its hard to find the frame where they are born (I tried to find the birthframe by putting them in a group and comparing if they already are in it, but it's not stable somehow). Just add a point attribute with $F after the fluid source in SOPs. I think the default FLIP setup is to source from points not volume, but I cant check right now. Edited May 12, 2012 by mawi Quote Link to comment Share on other sites More sharing options...
mawi Posted May 12, 2012 Share Posted May 12, 2012 Does anybody know how to add ids to flipfluid particles in H12. I tried all sorts but can't get it to work stably. Where are the particles genereated??? Even a non-than-perfect id would be OK. Dont take my word on it but, if I remember correct one would like to stay away from the pop-solver due to speed. The flip fluid is not particles, its points and therefor missing id. They are generated by merging in the source points into the Geometry data of the fluid. This is done in a SOP solver in the volume source DOP. Quote Link to comment Share on other sites More sharing options...
ikarus Posted May 15, 2012 Share Posted May 15, 2012 Does anybody know how to add ids to flipfluid particles in H12. I tried all sorts but can't get it to work stably. Where are the particles genereated??? Even a non-than-perfect id would be OK. Are you using the reseed particles option in the particle motion tab? Quote Link to comment Share on other sites More sharing options...
Annon Posted May 15, 2012 Share Posted May 15, 2012 I just did a quick test with the pop solver and had everything off apart from "Apply Rules". Didn't take any longer with a location and age node inside than if I disconnected the pop solver altogether. Quote Link to comment Share on other sites More sharing options...
Jason Posted May 15, 2012 Share Posted May 15, 2012 You should RFE this with SESI - I remember seeing discussion about ID usefulness; especially due to their potential storage cost, etc. Quote Link to comment Share on other sites More sharing options...
johner Posted September 8, 2012 Share Posted September 8, 2012 Just for completeness: Houdini 12.1.30: The FLIP Solver has a new option to add a unique id attribute to each particle. Additionally, the Reseeding operation has been updated to properly create new ids when generating new particles. Also in 12.0.706 Quote Link to comment Share on other sites More sharing options...
garf Posted August 5, 2019 Share Posted August 5, 2019 On 08/09/2012 at 8:39 PM, johner said: Just for completeness: Also in 12.0.706 Houdini 17.5.258 I'm getting duplicate ids when using FLIP and reseeding...... why would this be? Quote Link to comment Share on other sites More sharing options...
bunker Posted August 5, 2019 Share Posted August 5, 2019 I had the same issue before. you're probably just running out of IDs since it's only a 32 bits integer (2,147,483,647 max) It's going back to zero after that max value. it seems like a lot of particles, but after a few hundred frames it's likely that 2 particles have the same IDs. One solution is to add a secondary integer attribute to extend the range of IDs, you'll need to edit the FLIP solver's part where is ID is generated. hope that makes sense Quote Link to comment Share on other sites More sharing options...
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