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fractured vs rbd objects


oblong

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I have an example which shows rbd objects connecting constraints to each other, using apply relationships.

When i change the rbdobject nodes (which have 4 objects set in each) to rbd fractured objects, which , when I look in the Dops details - appear to be almost exact (apart from objid difference) why does the apply relationship node no longer set up any constraints?

As I say, the two object types appear identical in the Dop details list. There must be something fundamentally hidden from view which prevents this constraint loop....

Im simply trying to find a way to create a constraint for every object in the scene to connect to any other by using line segments as the information to apply relationships. This would be easy in SOPs. In Dops, it appears impossible ... I probably dont have the knowledge yet, but I must admit that there is simply no clue on how to resolve.

apply_rel_constraints01.hipnc

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I have an example which shows rbd objects connecting constraints to each other, using apply relationships.

When i change the rbdobject nodes (which have 4 objects set in each) to rbd fractured objects, which , when I look in the Dops details - appear to be almost exact (apart from objid difference) why does the apply relationship node no longer set up any constraints?

As I say, the two object types appear identical in the Dop details list. There must be something fundamentally hidden from view which prevents this constraint loop....

Im simply trying to find a way to create a constraint for every object in the scene to connect to any other by using line segments as the information to apply relationships. This would be easy in SOPs. In Dops, it appears impossible ... I probably dont have the knowledge yet, but I must admit that there is simply no clue on how to resolve.

If you disable the "fracture by name" parameter in the RBD fracture objects it kinda works, with the exception that it places all the constrained points in the origin.

The fractured obj doesn't calculate the individual positions of the objects until the simulation starts and that screws up the constraints in this setup you got.

I'm looking into a way to properly place the anchorpoints.

Cheers

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I made a set of points to represent the centroids of the objects and plugged those values in.

Still doesnt fix the issue. I seem to have made a chain of constraints, which explode over a few frames.

: attached a set up if you care to take a look.

If I could get a handle on what variables are for counting through which objects, and how the stamp can be used to access these loop counts... but knowing Dops there are probably a fair number of hoops that i have to jump through before i can ever get this to work.

Sending a set of line segments to Dops, to act as a rigging guide for auto constraints may now be a far off dream... is there a sesi programmer in the house!?


apply_rel_constraints02.hipnc

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if you want constraint between each box-ball of fractured objects then this is one possible solution

first create pivot information according to your centroids, doing this on fracture object directly ensures correct ids

then just reference pivot data as initial world space position of incoming objects.

look at the file

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Yeah, I got to the same point and I start to believe that this would just not work the way we are trying. Even in conversations with a friend we had trouble figuring stuff out, so quite probably there's another way around this specific problem.

It does make sense to me that what works on the left side of the switch certainly won't work for the right side. It'd be useful to figure out for something that I'm setting up myself too, but I guess for now I'll just keep it in the back of my mind.

Cheers

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Yes - I have an intuition that there is yet another way involving use of Stamp with the apply relationship to do this, but its just not jumping out at me. Frustrating business , because I now have to resort to much more mundane non procedural methods involving opdigits(everything) etc ... and multiple seperate groups of objects for constraining individually. Pity there is no more info.

The pivot idea was interesting to locate things, however chs("./object") didnt loop through anything and is always using the first location 0.

Edited by oblong
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Something is odd here. If we switch to rbd fracture then the object id's are not what you expect. For example 1 and 6 is missing. Make sure they have correct objectid and I suspect it will work.

Edited by Macha
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With object IDs that is what you get with Dops, and there is no changing those, also, notice the affectorids change to 0 2 3 4 6 etc instead of 0123456 etc

Suspect something inside Fractured object that messes with this.

Anim - check the hip you sent, it was trashed when i opened it with wrong rbdobject inputs.

i will play with the contents of rbdFractured and see if the objids can be changed around ...

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...

Anim - check the hip you sent, it was trashed when i opened it with wrong rbdobject inputs.

...

I tried it with both versions I currently have 11.1.22 and 11.0.733, it's working fine

sorry then, It must have been something changed since then, I will check when I get to newer build and post a new file

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