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RBD material fracture wood - break soft constraint?


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How do I go about breaking the soft constraints that have automatically been created by the rbd fracture material? 
In the one file, I am using connect adjacent pieces and the other, the constraint created by the rbd fracture material. please see attached files. 
Any advice will be much appreciated.





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Hi, Julian thanks for the file! It works great.

I don't understand why when using the shelf tools it ads the constraints network above the rigid body solver. I get an error when adding an SOP solver to delete the constraints.


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I think the shelf tool is fine - you can put the constraint network above the rigid body solver if you want. The error you get, I am guessing, is because you need to turn 'Attach Internal Constraints to Object' on the Constraint Network node to 'Off'. Having read the help on that option at least 50x I still have no idea why or what it means in practice but it does work if you turn it off :-)

glue to soft above.hipnc

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  • 11 months later...

'Attach internal constraint to object' changes where the constraint data is stored. By default, constraints are stored essentially in their own container, and as a result can apply across objects (e.g., linking a packed piece from rbd object 1 to a piece from rbd object 2). The downside is that the third-input SOP solver is always evaluated at the same stage in the simulation. The alternative (attaching the constraints to object), is to store constraints as a second geometry container inside an individual rbd object. The downside is that these constraints can no longer apply across objects. The upshot is that you can modify them whenever you like (e.g., pre or post-solve) using the inputs on the solver instead of on the constraint network. If you only have a single object in your sim (note that an object can have lots of pieces in the case of packed streams - the "object" is just the top level container), then it doesn't particularly matter whether this is on or off, but it will influence where you need to plug your SOP solver in.

Papagal44 - I get an error (from odforce) when I try to access your file...

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  • 2 months later...

Grayden, your explanation helps me understand 'Attach internal constraint to object' . Thanks.

Then,  I downloaded julian johnson's glue to soft above.hipnc., which contains only one RBD packed object, and tried to compare sim with the check box ON/OFF. Surprisingly sim results are different each other. I guess it causes by inside of sopSolver nodes. It would be great to have an answer if you have time to take a look. I really want to understand when I should turn on/off this function very well.

Best regards,


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