essencevfx Posted July 29, 2009 Share Posted July 29, 2009 I'm running into a bit of a headache with the Up-res solver on a Pyro (gas) sim. It seems to be removing a lot of values from my source sim when it solves. What this means for me , is areas where I have 'thin' density values (like thin streams of smoke/temp) in my lo-res, these are gone,(eroded away in a sense) in the upres sim. I wonder if there is a way to have the Up-Res only 'add' values to the souce sim. Is it possible I'm missing something here? Thanks in advance ! J. Quote Link to comment Share on other sites More sharing options...
bunker Posted July 30, 2009 Share Posted July 30, 2009 I have the exact same problem, from 80 to 160 voxels grid. I haven't find the cause of the problem or a 'real' solution either. But I did a quick fix using the "Smoke field modifier" in the pyro shader. You can keyframe the Range mapping values hope that helps Julien Quote Link to comment Share on other sites More sharing options...
pclaes Posted July 30, 2009 Share Posted July 30, 2009 As this is rather hard to test and I've only started playing with the microsolvers perhaps this could work: - Between the uprespyro fields initialization and the upressolver, you could fetch the data of the lowres. - Then use a gas calculate on "Maximum" to add the low-res to the up-res density. Have a look at the hip file. It might give weird results though and I am not sure if this works. But let us know whether it does or doesn't. upres_add_lowres_01.hipnc Quote Link to comment Share on other sites More sharing options...
bunker Posted July 31, 2009 Share Posted July 31, 2009 Nice one Peter, I'm going try that. Quote Link to comment Share on other sites More sharing options...
essencevfx Posted July 31, 2009 Author Share Posted July 31, 2009 (edited) Yes I'll have a look at that solution, nice one ! I was trying to avoid jumping into the solver hoping for a possible solution on the surface but I cant find one either. I'm going to have a look at the curl noise vop that's generating the noise to begin with to see if there are any negative values being mapped....Ive remapped a bit in the shader but there are values that are gone, so sometimes nothing to re-map .... Edited July 31, 2009 by essencevfx Quote Link to comment Share on other sites More sharing options...
pclaes Posted July 31, 2009 Share Posted July 31, 2009 sometimes nothing to re-map .... The main thing the upres does is push things around (advect) with extra layers of noise in the velocity. I believe if you have the time spend some time on the pyrosolver and the microsolvers. They are really powerful pieces of mathematics that you can use. I've already started missing some of that functionality in sops. Personally I really do not like the way they do the "source from object" with the source relationship and all that. If you dig through it at the lowest level, all it does is a gas calculate that takes the maximum from the source field and copies it to the fuel/density field. (pretty much the same operation for adding that low-res field to the up-res). I will be posting my own thread where I will share some tools to manipulate fields (in sops first and then in dops) - which I find a lot more understandable and logical than the source relationship. For beginning users it might seem easier, but I find the maths easier than artificial relationships. Quote Link to comment Share on other sites More sharing options...
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