tabu Posted December 23, 2020 Share Posted December 23, 2020 For one of my projects, I am using Vellum hair to simulate my tree branches, but simming gets really slow. To make my curves stiff enough I need to bump substeps to more than 3 and also constraint iterations to more than 50k and obviously, simming gets really slow. I am not sure if I am doing something wrong that I need to bump numbers so high or this is normal to wait so long for vellum simulations? Main settings I am changing are stretch and bend. Before - I made my tree real life scale, but even now, when I scaled it a bit down, I still need to bump my constraint iterations to more than 50K. P.S I have 64GB Ram and Ryzen 3900x, so I am not sure if my hardware is not good enough to sim it. Quote Link to comment Share on other sites More sharing options...
Vinz Posted December 23, 2020 Share Posted December 23, 2020 (edited) From what I understand, you are trying to sim the whole geometry of the branches/tree though the solver. Try to run only the curves though the solver (quite low res without any polys) then res up your curves and generate final geometry after solve. I am just catching you post on the fly as it sounds familiar with a similar issue I had solved here: Edited December 23, 2020 by Vinz 1 Quote Link to comment Share on other sites More sharing options...
tabu Posted December 23, 2020 Author Share Posted December 23, 2020 Oh no no, I am not simming whole geometry, I have curves and I have even separated them into a different hierarchy. But even siming my first level(in the photo)l, which is 57 primitives, I need to use 3 substeps and 30k constraint iteration (and still I am not getting required quality) Quote Link to comment Share on other sites More sharing options...
Vinz Posted December 24, 2020 Share Posted December 24, 2020 Probably post your scene if you can so me or someone can take a look and test the playback (I have exactly the same hardware specs as you) Quote Link to comment Share on other sites More sharing options...
Noobini Posted December 24, 2020 Share Posted December 24, 2020 (edited) 30k constrain iterations ?!?!?!?!?!?! surely there has to be a point where you say enough is enough ? that's a yeah naaaaaaaaaaaaaaaaaaaah for me. https://www.sidefx.com/tutorials/vellum-constraint-features-john-lynch-h18-masterclass/ Go and study the tree_density file from John Lynch (the gif you see here is 1 substep, 100 const iterations, sims in real time) Edited December 24, 2020 by Noobini 2 Quote Link to comment Share on other sites More sharing options...
tabu Posted January 3, 2021 Author Share Posted January 3, 2021 On 24/12/2020 at 10:14 PM, Noobini said: 30k constrain iterations ?!?!?!?!?!?! surely there has to be a point where you say enough is enough ? that's a yeah naaaaaaaaaaaaaaaaaaaah for me. https://www.sidefx.com/tutorials/vellum-constraint-features-john-lynch-h18-masterclass/ Go and study the tree_density file from John Lynch (the gif you see here is 1 substep, 100 const iterations, sims in real time) Thank you very much for this! Actually, I have no idea how I skipped that part at the beginning which was so vital. Now everything works fine with no more than 1k iterations. Thank you very much! Quote Link to comment Share on other sites More sharing options...
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