Annon Posted January 23, 2012 Share Posted January 23, 2012 I've been struggling all day to get a fractured object to start to collapse after an object has gone past it. I've been using apply relationships to release pin constraints after a plane has gone past. I've tried applying attributes at SOP level and using them to drive the active state etc... If anyone could give me some advice on how to achieve what I'm after I'd be forever indebted. I'm sure I'm just over complicating something that should be very simple. Thanks Christian *Note, this is a simplified scene that is the most basic representation of a starting point. In reality I'm doing this on some dense geometry. Quote Link to comment Share on other sites More sharing options...
Annon Posted January 23, 2012 Author Share Posted January 23, 2012 *forgot to actually attach the file: simplifiedFractureHelpScene.hip Quote Link to comment Share on other sites More sharing options...
Macha Posted January 23, 2012 Share Posted January 23, 2012 (edited) Every piece in your geo accelerates at the same speed. That's a property of gravity. If you randomize it, or give individual pieces a different push it will work. For example, try the following expression in the gravity force. -10*$OBJID Also, try playing with the Sampling mode and make sure the pieces' sdf don't intersect (offset or resolve penetration) Edited January 23, 2012 by Macha Quote Link to comment Share on other sites More sharing options...
efx Posted January 24, 2012 Share Posted January 24, 2012 Hi, I did cloth sim with pin constraint about more than year ago, So I am not sure you can use same way & I hope I remember well.... If you want to use point attribute from Sop level, you can not just set or animate attribute in Sop level. I used multi-solver and used 2 sop solver. I remember you need to create the attribute Sop level first. Inside Dops, Use fist sop solver before the your main solver to update pin constraints attribute from the 2nd one. And put 2nd one after your main solver and inside that, You animate or use some expression to release pin constraints attribute. As I remember you don't have to use apply relationships. I am sorry right now I don't have the hip file. I hope this helps a bit!! Cheers Quote Link to comment Share on other sites More sharing options...
oblong Posted February 15, 2012 Share Posted February 15, 2012 Hi, I did cloth sim with pin constraint about more than year ago, So I am not sure you can use same way & I hope I remember well.... If you want to use point attribute from Sop level, you can not just set or animate attribute in Sop level. I used multi-solver and used 2 sop solver. I remember you need to create the attribute Sop level first. Inside Dops, Use fist sop solver before the your main solver to update pin constraints attribute from the 2nd one. And put 2nd one after your main solver and inside that, You animate or use some expression to release pin constraints attribute. As I remember you don't have to use apply relationships. I am sorry right now I don't have the hip file. I hope this helps a bit!! Cheers Quote Link to comment Share on other sites More sharing options...
oblong Posted February 15, 2012 Share Posted February 15, 2012 Any more on this? When I read that 'you dont have to use apply relationship' I was suddenly gripped with anticipation for an actual example? This is a very crucial problem - i cannot change the number of constraints, once they are set up. Even if I reduce the number during the animation. Quote Link to comment Share on other sites More sharing options...
Annon Posted February 15, 2012 Author Share Posted February 15, 2012 Well what Macha was saying was to apply a different seed of gravity to each object, so something like "1-(rand($ID) * 9.8)" which will work in some situations and is handy in general. I'll take a look into my original problem at some point and post up a simple scene, the one I was using was a bit chaotic... Quote Link to comment Share on other sites More sharing options...
oblong Posted February 15, 2012 Share Posted February 15, 2012 Well what Macha was saying was to apply a different seed of gravity to each object, so something like "1-(rand($ID) * 9.8)" which will work in some situations and is handy in general. I'll take a look into my original problem at some point and post up a simple scene, the one I was using was a bit chaotic... I was asking about constraints and using apply relationship .. Quote Link to comment Share on other sites More sharing options...
Annon Posted February 15, 2012 Author Share Posted February 15, 2012 I know, as I said: "I'll take a look into my original problem at some point and post up a simple scene" Quote Link to comment Share on other sites More sharing options...
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