baadu Posted April 1, 2009 Share Posted April 1, 2009 Hi I guess its a simple solutiion but I cant get around it . I know how to use the merge node to set up collision relationship between two different RBD objects but I have this RBD fractured object and I dont want any collisions within itself . How do I turn their internal collisions off. to make this more clear heres a simplified example :- suppose I have a a geometry object with 2 spheres within it . I turn this in to RBD fractured object. Now I dont want these 2 spheres to collide with each other but they can collide with the groundplane . HOW DO I DO THIS ? I have attached an example file - can someone please modify it - both the spheres have to be ONE GEOMETRY as RBD Fractured object (each sphere is a seperate group but same GEOMETRY) thanks spheres.hip Quote Link to comment Share on other sites More sharing options...
old school Posted April 1, 2009 Share Posted April 1, 2009 Turn the Fractured RBD object in to a Glue RBD object and set the internal glue to -1 (infinite strength). Next use an RBD State DOP wired in to an Apply Data DOP which is inserted after the Glue RBD DOP. In the RBD State DOP, set the impulse to whatever you want that is enough to shatter the pieces. Make sure to make that parameter activation set to "Apply Always". Keyframe animate the Activation parm on the Apply Data DOP to kick in whenever you want. I believe a simple RMB on the Fractured RBD DOP and choose "Change Type..." and change it to an Glue RBD Object. Keep the name and keep the parms. The two are almost identical. See the attached file how to set this up. internal_glue_off_on_simple.hip Glue is in some ways a bit of a bad choice for this technology. It can also be called RBD hierarchies because that is exactly what glue takes advantage off: A hierarchy of RBD objects. It just so happens that Glue was the most used option of RBD hierarchies where you create a value between the pieces in the RBD hierarchy and when one of those RBD objects receives an impact impulse force greater than the glue strength the piece removes itself from the hierarchy. Another bonus for using rbd hierarchies (Glue) is that they evaluate much faster as the entire hierarchy moves with a single transform. That of the parent RBD object. Quote Link to comment Share on other sites More sharing options...
johner Posted April 1, 2009 Share Posted April 1, 2009 (edited) Turn off "Make Objects Mutual Affectors" in your RBDSolver node, and in the Merge node change the Affector Relationship from "Mutual" to "Left Inputs affect Right". Selecting one of the sphere objects in the DetailsView should show their affectors- you only want the ground plane in there. Edit: oof, answered before I saw Jeff's response. Maybe I misunderstood the question... Edited April 1, 2009 by johner Quote Link to comment Share on other sites More sharing options...
baadu Posted April 1, 2009 Author Share Posted April 1, 2009 thanks for the reply guys I'll chk it out Cheers Baadu Quote Link to comment Share on other sites More sharing options...
baadu Posted April 1, 2009 Author Share Posted April 1, 2009 Hi Oldschool Thanks for your suggestion but it still doesnt solve my problem . you see in the file that you posted the individual boxes still collide with each other . I need the boxes to Not collide with each other but collide only with the groundplane. and is it true that RBD glue fractured objects is faster than Rbd fractured? thanks dude Baadu Turn the Fractured RBD object in to a Glue RBD object and set the internal glue to -1 (infinite strength). Next use an RBD State DOP wired in to an Apply Data DOP which is inserted after the Glue RBD DOP. In the RBD State DOP, set the impulse to whatever you want that is enough to shatter the pieces. Make sure to make that parameter activation set to "Apply Always". Keyframe animate the Activation parm on the Apply Data DOP to kick in whenever you want. I believe a simple RMB on the Fractured RBD DOP and choose "Change Type..." and change it to an Glue RBD Object. Keep the name and keep the parms. The two are almost identical. See the attached file how to set this up. internal_glue_off_on_simple.hip Glue is in some ways a bit of a bad choice for this technology. It can also be called RBD hierarchies because that is exactly what glue takes advantage off: A hierarchy of RBD objects. It just so happens that Glue was the most used option of RBD hierarchies where you create a value between the pieces in the RBD hierarchy and when one of those RBD objects receives an impact impulse force greater than the glue strength the piece removes itself from the hierarchy. Another bonus for using rbd hierarchies (Glue) is that they evaluate much faster as the entire hierarchy moves with a single transform. That of the parent RBD object. Quote Link to comment Share on other sites More sharing options...
baadu Posted April 2, 2009 Author Share Posted April 2, 2009 Hi johner Thanks for your reply . I tried your way but with no luck or maybe I'm missing something , could you modify the file I posted if possible. Cheers Baadu Turn off "Make Objects Mutual Affectors" in your RBDSolver node, and in the Merge node change the Affector Relationship from "Mutual" to "Left Inputs affect Right".Selecting one of the sphere objects in the DetailsView should show their affectors- you only want the ground plane in there. Edit: oof, answered before I saw Jeff's response. Maybe I misunderstood the question... Quote Link to comment Share on other sites More sharing options...
johner Posted April 2, 2009 Share Posted April 2, 2009 Thanks for your reply . I tried your way but with no luck or maybe I'm missing something , could you modify the file I posted if possible. Well, I'm still not sure I understood the question correctly, but attached is what I was talking about. spheres_nocollide.hip Quote Link to comment Share on other sites More sharing options...
baadu Posted April 6, 2009 Author Share Posted April 6, 2009 Well, I'm still not sure I understood the question correctly, but attached is what I was talking about. Wow that works thanks a lot dude. Quote Link to comment Share on other sites More sharing options...
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