Symbolic Posted April 14, 2008 Share Posted April 14, 2008 Hi, I have an RBD Fractured object based simulation... There are 50 chunks. The simulation is ok, at the next stage... I would like to isolate one specific chunk... run it through chops... and put it back together with the others. The isolation process is easy... The problem is that: I read the target chunk with a "geometry" chop... run it through a lag and then export it... but the lag is applied to every single point... and that makes the object to deform instead of altering its path... So how can I isolate a single object among lots of RBD Fractured objects, alter the path of motion (ex: slow it down) and put it back... I have seen a soluton at: http://forums.odforce.net/index.php?showto...chops&st=12 it takes every single object... runs it through chops and transfers tx ty tz rx ry rz to the object level... to lots of Geometries at OBJ level... Any ideas how to do that in a more efficient way? Cheers. Quote Link to comment Share on other sites More sharing options...
GallenWolf Posted April 15, 2008 Share Posted April 15, 2008 Hmmm could you try the dynamics chop instead of the geo chop? That way you bring in the T? R? etc parameters, not the points. I'll see if I can find a bit of a moment to whip up an example. Alvin Quote Link to comment Share on other sites More sharing options...
Symbolic Posted April 15, 2008 Author Share Posted April 15, 2008 Hmmm could you try the dynamics chop instead of the geo chop? That way you bring in the T? R? etc parameters, not the points. I'll see if I can find a bit of a moment to whip up an example.Alvin Well... I know how to do it with the dynamic chop... but then you have to recreate each chunk of your fractured object in separate geometry at object level and feed the output of the dynamics chop into those... It works... but is a little tedious. Quote Link to comment Share on other sites More sharing options...
johner Posted April 15, 2008 Share Posted April 15, 2008 (edited) Well... I know how to do it with the dynamic chop... but then you have to recreate each chunk of your fractured object in separate geometry at object level and feed the output of the dynamics chop into those... It works... but is a little tedious. Actually you can just feed the lagged t? and r? channels into a Transform SOP on just the desired chunk at the SOP level, then merge all the chunks back together. See attached example. Edit: realized you could do it without the delete's. Attached as well. fractured_lag.hipnc fractured_lag_nodelete.hipnc Edited April 15, 2008 by johner Quote Link to comment Share on other sites More sharing options...
Symbolic Posted April 15, 2008 Author Share Posted April 15, 2008 Hey! Thanks. I will look at it tomorrow at work. Cheers. Quote Link to comment Share on other sites More sharing options...
Symbolic Posted April 16, 2008 Author Share Posted April 16, 2008 Hi johner, Thanks! That works perfect... Had some problems with the pivot though... at the beginning... the "p" for the DOPs pivot seems to cause troubles... but then I used your $GCX $GCY $GCZ... which I have never heard about before... and it works... Now it is just matter of improving my CHOPs skills... CHOPs are really great! and I am scared that Side Effects will give them up at some point... since they are a separate system and has not been touched since PRISMS maybe... I hope this never happens. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
johner Posted April 16, 2008 Share Posted April 16, 2008 (edited) Hi johner,Thanks! That works perfect... Had some problems with the pivot though... at the beginning... the "p" for the DOPs pivot seems to cause troubles... but then I used your $GCX $GCY $GCZ... which I have never heard about before... and it works... Now it is just matter of improving my CHOPs skills... CHOPs are really great! and I am scared that Side Effects will give them up at some point... since they are a separate system and has not been touched since PRISMS maybe... I hope this never happens. Thanks for the help. Sure thing. Yeah, I'm a big fan of CHOPs myself. I'm always happy to realize something can be done in CHOPs rather than (or even on top of, as in this case) simulation. And I really doubt they're going away - they're just too useful and too much of a competitive advantage for Houdini, IMO. Jeff's Old School blog had some great recent tutorials on them. As to recent improvements, I know for example the BlendPose viewport tool (which I have yet to wrap my head around) introduced in H9 is implemented via a new BlendPose CHOP. And of course the Dynamics CHOP itself didn't exist until DOPs in H8, right? Good luck! Edit: oh yeah, and Andrew Lowell's really nice tutorial: http://www.sidefx.com/index.php?option=com...&Itemid=132 Wasn't Andrew about to release an e-book on CHOPs? Edited April 16, 2008 by johner Quote Link to comment Share on other sites More sharing options...
Symbolic Posted April 17, 2008 Author Share Posted April 17, 2008 Thanks! Quote Link to comment Share on other sites More sharing options...
Guest Swann Posted April 17, 2008 Share Posted April 17, 2008 Wasn't Andrew about to release an e-book on CHOPs? I heard about 2 DVD's ! One ready for relase, and second in production. Hm, Strange. Quote Link to comment Share on other sites More sharing options...
pagefan Posted April 17, 2008 Share Posted April 17, 2008 Nah, not two dvd's, a motion picture, three episodes, Lord of the CHOPS ....i think he just made an e-book Quote Link to comment Share on other sites More sharing options...
andrewlowell Posted April 17, 2008 Share Posted April 17, 2008 (edited) Nah, not two dvd's, a motion picture, three episodes, Lord of the CHOPS....i think he just made an e-book Yeah I just made the cover-page last night ... I'll be giving a short talk about it today at HOUPLA. It's in the final stages of SESI approval. This isn't easy by the way .. I had to re-write a few chapters and make a new one also (ask peter ) But, it's made it a much better product I think, and it will reach a much wider audience with this mark .. not just tech-nerds such as myself that like CHOPs, but people in all stages of learning and production (at least I hope). I don't want to shoot myself in the foot .. but it should be out any week now. (I don't think SESI is getting rid of CHOPs anytime soon, hey maybe they'll even enhance the spatial audio capabilities eventually!) Edited April 17, 2008 by andrewlowell Quote Link to comment Share on other sites More sharing options...
Netvudu Posted April 18, 2008 Share Posted April 18, 2008 getting rid of CHOPs?...umm...yeah, definitely. They should take them out, as well as other useless stuff such as keyframing (come on, that Quote Link to comment Share on other sites More sharing options...
Symbolic Posted April 18, 2008 Author Share Posted April 18, 2008 Good to hear that CHOPs will be improved... and looking forward for that CHOPs e-book... Quote Link to comment Share on other sites More sharing options...
Symbolic Posted April 20, 2008 Author Share Posted April 20, 2008 Hi! I finally ended up using the technique described at: http://forums.odforce.net/index.php?showto...chops&st=12 Which works good... but it takes some time to set up. So I am reading the dynamics into a CHOP network with the dynamics chop... and then feeding the data to object level geometries (each geometry has one chunk). Now I am at the next step... The reason for doing all of this was because I was getting some high frequency jitter on some of my chunks... So now I am trying to apply a "filter chop" at a specific ranges so I can fix the jitter... Do you have any ideas about how can I limit the effect of the filter chop just between a specific range? Thanks for the help so far... Cheers. Quote Link to comment Share on other sites More sharing options...
Symbolic Posted April 20, 2008 Author Share Posted April 20, 2008 ... or maybe freeze the movement of the chunk for a while and blend to the next animation after a while... Quote Link to comment Share on other sites More sharing options...
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