gpapaioa Posted August 22, 2015 Share Posted August 22, 2015 Greetings everyone, I am experiencing different behaviour of FLIP collisions when I am using VDB volumes, cached and non-cached. So I am wondering if anyone has an explanation and which method is more proper. Thank you. Quote Link to comment Share on other sites More sharing options...
woodenduck Posted August 22, 2015 Share Posted August 22, 2015 Can you post a hip file? There should be no difference in the cached and live data. Quote Link to comment Share on other sites More sharing options...
gpapaioa Posted August 22, 2015 Author Share Posted August 22, 2015 (edited) Its a commercial project so I cant but I will try some simple setup as soon as I got time. The behaviour is not very different, its a container filling up and when I use live data its a bit more "splashy" Edited August 22, 2015 by gpapaioa Quote Link to comment Share on other sites More sharing options...
anim Posted August 22, 2015 Share Posted August 22, 2015 make sure you are caching your data with the same number of substeps as your max substeps in flips (considering that you are using just those and not combining with additional dopnet substeps) Quote Link to comment Share on other sites More sharing options...
gpapaioa Posted August 23, 2015 Author Share Posted August 23, 2015 Got it. Its static geometry not deforming so I cached only one VDB file. So I should eg. cache the whole sequence even if its static, add a timeblend before vel calculation in order to have the data appearing on every substep. Correct me if I am wrong please. Thank you. Quote Link to comment Share on other sites More sharing options...
fathom Posted August 23, 2015 Share Posted August 23, 2015 if it's static geometry what exactly is "cached" about it? Quote Link to comment Share on other sites More sharing options...
gpapaioa Posted August 23, 2015 Author Share Posted August 23, 2015 Dont quite understand you question. Its high res VDB, written on disk. Do you mean its not worthy to cache geo when its static? Quote Link to comment Share on other sites More sharing options...
anim Posted August 23, 2015 Share Posted August 23, 2015 Got it. Its static geometry not deforming so I cached only one VDB file. So I should eg. cache the whole sequence even if its static, add a timeblend before vel calculation in order to have the data appearing on every substep. Correct me if I am wrong please. Thank you. no, if it's static then one file is fine and there should be no difference in sim if the non-cached geometry and the cached geometry read from disk is the same, which you better doublecheck for deforming geo you better cache with correct amount of substeps (File Cache SOP has that option) because timeblend will not necessarily help you as you are possibly dealing with VDB volumes Quote Link to comment Share on other sites More sharing options...
gpapaioa Posted August 23, 2015 Author Share Posted August 23, 2015 Great. Thank you for all the tips. Quote Link to comment Share on other sites More sharing options...
tricecold Posted August 25, 2015 Share Posted August 25, 2015 hey Georgios, whats up buddy; If you have a deforming object cache the whole sequence as mentioned before, it helps to cache with at least .5 increments, even if you think you wont need it. Unless the deforming object is ticked on static geometry node in DOPS , Houdini will only create a collision geo on creation frame and will never update it. So You dont have to cache the whole sequence, but you can still use the VDBs as proxy collision generator, as they tend to do a lot better and faster then SDF . Quote Link to comment Share on other sites More sharing options...
gpapaioa Posted August 25, 2015 Author Share Posted August 25, 2015 Hey man, From what I have read on the forum, in order to have a container fill up with fluid you have to use Source Volume collision. Otherwise you have collision but the container wont fill up. Am I correct? Cause the H14 help file says that this method of collision is out-dated. Quote Link to comment Share on other sites More sharing options...
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