dangerweenie Posted October 4, 2011 Share Posted October 4, 2011 (edited) Howdy, I'm having some trouble getting some large chunks of simulated geo to refracture when it hits the ground. Basically I am getting impact "starburst" pattern type fractures on the metaball locations (which is good) and where the glass cylinder is resting and making contact on the ground (which is not bad but I don't neccessarily want that). The rear pieces and the pieces far away from the metaballs are breaking off from the initial impact cracks, but they are not refracturing when they drop and hit the ground. I've upped "max fractures" quite a bit, but I end up getting super-tiny, granulated type looking pieces everywhere (especially @ the metaball areas), which totally slows the sim down. I tried scaling up the minimum value for fracture consideration, but I don't know how to get the volume of a piece of geo, and even experimenting did not seem to vary things in a helpful way. I tried changing the glue setting in the RBDSolver, didn't really do anything (I'm assuming that the glue attrs only really matter when you creature a glue RBD object). Changing the density of the glass didn't seem to do it either. Kind of stumped, but I'm very new to this so I'm sure I am missing something obvious. I started trying to group just the larger chunks and then run them through another fractureparams node, but I pretty much have no idea what I'm doing. Time would be better spent listening to some ppl with experience. I've found Johner's extensive contributions on Voronoi and dynamic fracturing to be fascinating, but I'm still kind of taking it all in and am not sure how to apply that advice quite yet. Any suggestions would be much appreciated. I've attached a screen shot - as you can see, the shot will be for a person that is inside a giant glass bottle "all we see is the cylindrical part", and with their hands, they push out, fracturing and breaking the glass apart with an outwards force (at the respective negative metaball/magnetforce locations). The .hip file is also attached. Best, Matt refractureHelp.hip Edited October 4, 2011 by dangerweenie Quote Link to comment Share on other sites More sharing options...
ehsan parizi Posted October 4, 2011 Share Posted October 4, 2011 (edited) Howdy, I'm having some trouble getting some large chunks of simulated geo to refracture when it hits the ground. Basically I am getting impact "starburst" pattern type fractures on the metaball locations (which is good) and where the glass cylinder is resting and making contact on the ground (which is not bad but I don't neccessarily want that). The rear pieces and the pieces far away from the metaballs are breaking off from the initial impact cracks, but they are not refracturing when they drop and hit the ground. I've upped "max fractures" quite a bit, but I end up getting super-tiny, granulated type looking pieces everywhere (especially @ the metaball areas), which totally slows the sim down. I tried scaling up the minimum value for fracture consideration, but I don't know how to get the volume of a piece of geo, and even experimenting did not seem to vary things in a helpful way. I tried changing the glue setting in the RBDSolver, didn't really do anything (I'm assuming that the glue attrs only really matter when you creature a glue RBD object). Changing the density of the glass didn't seem to do it either. Kind of stumped, but I'm very new to this so I'm sure I am missing something obvious. I started trying to group just the larger chunks and then run them through another fractureparams node, but I pretty much have no idea what I'm doing. Time would be better spent listening to some ppl with experience. I think if you want to fracture your geometry again and again, there's only one way to do it and it's by increasing the max fractures, and it does slow down your sim. But if someone has a solution for that without slowing down the sim, that would be great! Anyway, I played with your file, and did some changes, not sure if this is what you want, but you can take a look at the attached file, and hopefully that helps a bit. one more thing, that glue thing in rbd object node, is not an internal glue, if you wanna have internal glue, you need to use rbd glue object. refractureHelp_01.hipnc Edited October 4, 2011 by ehsan parizi Quote Link to comment Share on other sites More sharing options...
dangerweenie Posted October 5, 2011 Author Share Posted October 5, 2011 Hey, Thanks so much for helping out. I'm simming it right now. The problem I've noticed with this (and I think I read about it here on the forums) is that when I increase the "exterior" points, they end up fracturing before the impact... so in this case, the geometry fractures as a whole first (across the entire surface), and only after that does the metaball impact seem to start fracturing. Since the metaball impact is the source of the directed fracture, one would want it to be the first area to break, followed by the rest. Is the only solution to this to keyframe the visibility of the fracture vs. the unbroken geo? What about spreading hte fracture from one part to the rest? Sorry for all the questions! Thanks again, Matt I think if you want to fracture your geometry again and again, there's only one way to do it and it's by increasing the max fractures, and it does slow down your sim. But if someone has a solution for that without slowing down the sim, that would be great! Anyway, I played with your file, and did some changes, not sure if this is what you want, but you can take a look at the attached file, and hopefully that helps a bit. one more thing, that glue thing in rbd object node, is not an internal glue, if you wanna have internal glue, you need to use rbd glue object. Quote Link to comment Share on other sites More sharing options...
csp Posted November 3, 2011 Share Posted November 3, 2011 hi Mat, did you managed to find a solution to that? because I have the same problem and looking fora proper solution. cheers Hey, Thanks so much for helping out. I'm simming it right now. The problem I've noticed with this (and I think I read about it here on the forums) is that when I increase the "exterior" points, they end up fracturing before the impact... so in this case, the geometry fractures as a whole first (across the entire surface), and only after that does the metaball impact seem to start fracturing. Since the metaball impact is the source of the directed fracture, one would want it to be the first area to break, followed by the rest. Is the only solution to this to keyframe the visibility of the fracture vs. the unbroken geo? What about spreading hte fracture from one part to the rest? Sorry for all the questions! Thanks again, Matt Quote Link to comment Share on other sites More sharing options...
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