Move center of mass to custom position

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Hello,

I want to have a hanging rigid body. By default the pin constraint is created in the center of mass. I want to move the center of mass to a custom position. How can I achieve this?



Any help would be appreciated. Thanks.

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Screenshot 2024-05-19 125537.png (805.8 KB)

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Move the packed RBD to the origin, unpack the geo, move the polygon geometry around so the world origin is where you want the center of mass to be, re-pack the geometry and set the pivot location to "Origin". Using the RBD Configure SOP, enable the "Compute Center of Mass" option and set it to 0.

Rather than changing the center of mass however, even though the constraint points are created by default at the objects' center of mass, you can move those constraint anchor points around.
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Rather than changing the center of mass however, even though the constraint points are created by default at the objects' center of mass, you can move those constraint anchor points around.

How?
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If we're talking of rbd constraints created in SOPs, it's simply a matter of selecting the point, dropping a transform SOP and moving it.

Here's an example of moving the center of mass and a couple examples of moving constraint anchor points around.

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ConstraintAnchorPositions.hip (823.1 KB)

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If we're talking of rbd constraints created in SOPs

I have created an rbd pin constraint in DOP.

How would you go about moving constraint anchor points in a DOP Network?

Thanks in advance.
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The RBD Pin Constraint DOP's "Constrained Location" specifies where on the RBD object to create the anchor position.
The "Goal Location" allows you to specify either a world space location to pin the constrained anchor position to, or a location relative to a specified goal Object.

I've updated the example with the RBD Pin Constraint DOP for you.

Attachments:
ConstraintAnchorPositions.hip (860.7 KB)

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