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josh_hakim
I am currently working through a houdini destruction tutorial and the glue constraints one hold when there is one object in the scene. Once two objects are in the scene together, the glue constraint fails.
Josh

The points on your constraint network reference objects with names such as ‘piece0’, but that's ambiguous since there are multiple packed primitives in your scene which have that name.

In Houdini 14, constraint networks allow you to optionally prefix the packed primitive name with the DOP Object name (e.g. ‘Roof_Side/piece0’) to fix the ambiguity - shelf tools such as RBD Glue Object will set this up automatically. Otherwise, you can adjust the name prefix on the Voronoi Fracture SOP (or the Assemble SOP, depending on where your name attribute is being generated in your setup) to be unique.

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Technical Discussion » Constraints Getting Stuck


cwhite: 793 posts; Offline

April 15, 2015 22:54:13

I don't recall fixing any bugs with cone twist constraints since the H14 release, so please file a bug report (https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=15603) [sidefx.com] if you think there is an issue.

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Houdini Indie and Apprentice » Connect Adjacent Pieces minimum radius?


cwhite: 793 posts; Offline

April 15, 2015 18:21:14

There's nothing built in, so I'd suggest submitting an RFE for this.

It's fairly straightforward to do in VEX using the pcfind function, though (or in VOPs with the Point Cloud Find node) - the Connect Adjacent Pieces SOP is just a digital asset, so you can take a look inside at what it does when the Connection Type parameter is set to Adjacent Points.

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Technical Discussion » Constraints Getting Stuck


cwhite: 793 posts; Offline

April 15, 2015 18:07:13

The expression is for the ‘Overwrite with SOP’ parameter on the Constraint Network SOP. If you're opening an old file with a more recent build of H14, you can just revert that parameter to its default expression.

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Technical Discussion » ConeTwist Constraint Setup, H13 - H14


cwhite: 793 posts; Offline

March 28, 2015 11:59:21

I'm not sure why editing the Connect Adjacent Pieces SOP is necessary - I think the “Adjacent Pieces from Points” mode does what you're looking for?

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Technical Discussion » adjacent pieces coming back after impact.


cwhite: 793 posts; Offline

March 26, 2015 10:19:52

It sounds like you might be hitting the same issue as https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=37732. [sidefx.com] If resetting that parameter's expression to the default doesn't fix your issue, then I'd suggest posting a file and/or sending it to support.

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Houdini Lounge » Questions about Houdini Bullet


cwhite: 793 posts; Offline

March 16, 2015 10:08:48

Also note that in H14 you can use the ‘collisionignore’ point attribute to filter collisions against specific DOP objects, or against groups of packed primitives based on the ‘collisiongroup’ attribute (these are documented under the Collision Attributes section of https://www.sidefx.com/docs/houdini14.0/nodes/dop/rbdpackedobject) [sidefx.com]

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Technical Discussion » Houdini 14 Glue Network changes


cwhite: 793 posts; Offline

March 12, 2015 16:56:20

It would be helpful to attach a file (or submit a bug to support)

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Houdini Learning Materials » RBD Glue Object is overly attached to itself?


cwhite: 793 posts; Offline

Feb. 18, 2015 13:02:13

You probably need to update to a more recent build of H14:

Friday, January 16, 2015
Houdini 14.0.216: Fixed a bug in the default expression for the Overwrite with SOP parameter on Constraint Network DOP, which caused the constraint network geometry to be re-imported after the first frame even if it wasn't time dependent.

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Technical Discussion » Issues with Bullet in H14


cwhite: 793 posts; Offline

Feb. 9, 2015 16:06:01

The behaviour you're seeing appears to have been caused by a change made in 14.0.207:

Houdini 14.0.207: Fixed a bug in the Bullet library where angular momentum was not correctly conserved. This sometimes caused objects to exhibit unexpected behavior, such as a tall and thin object being unable to topple over.

I've reverted that change in tomorrow's build, since it caused some stability issues in certain situations (such as your attached file) that are more severe than the original bug.

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Technical Discussion » H14 Bullet generating too much impact data


cwhite: 793 posts; Offline

Jan. 29, 2015 10:06:04

That memory usage sounds suspiciously high - I'd suggest sending a bug report with that file to support.

Turning off “Add Impact Data” will prevent the Bullet solver from recording anything to the “Impacts” subdata on the DOP object - that can reduce the memory usage somewhat if there are many impacts and you don't have any need for that data.

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Technical Discussion » RBD Initial State /w Packed Primitives


cwhite: 793 posts; Offline

Jan. 27, 2015 22:37:41

Currently, the initial pivot needs to be set to a sensible value (e.g. P) - that's what happens behind the scenes in the RBD Point Object. There's an active RFE to improve this behaviour, though, and make it simpler to correctly set up initial angular velocities.

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Technical Discussion » RBD Initial State /w Packed Primitives


cwhite: 793 posts; Offline

Jan. 27, 2015 18:57:38

In H14, support for animated / deforming packed primitives is built-in, via the Initial Object Type menu. (this just sets the initial values for the ‘animated’ and ‘deforming’ point attributes).

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Technical Discussion » Glue issue in Houdini 14


cwhite: 793 posts; Offline

Jan. 25, 2015 10:15:42

See https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=37344 [sidefx.com]

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Technical Discussion » Houdini 14 Glue Network changes


cwhite: 793 posts; Offline

Jan. 23, 2015 16:37:26

There was a bug in the default expression for the Overwrite with SOP parameter, which is fixed in 14.0.216.

The shelf tool also switched to putting down an Attribute Create node instead of two Attribute Wrangle nodes in order to be a bit more friendly to beginners.

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Houdini Indie and Apprentice » H14 - Rigid body emitter


cwhite: 793 posts; Offline

Jan. 21, 2015 14:00:39

There was a bug in the RBD Packed Object DOP that caused it to not import the geometry if the object's creation frame was not on the first simulation frame. This is fixed in tomorrow's build (14.0.221)

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Technical Discussion » Constraints Getting Stuck


cwhite: 793 posts; Offline

Jan. 20, 2015 11:23:21

There was a bug in the default expression for the ‘Overwrite with SOP’ parameter, which caused the constraint network to be re-imported from the SOP path on every frame.

The default expression is fixed in 14.0.216 - I've also pasted the corrected expression below, since I don't think daily builds are being published yet:

if hou.hscriptExpression(“$SF”) == 1:
return 1
else:
node = hou.node(ch(“soppath”))
return node.isTimeDependent() if node else 0

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Houdini Lounge » vopsop H14?


cwhite: 793 posts; Offline

Jan. 16, 2015 20:41:50

http://www.sidefx.com/docs/houdini14.0/news/14/geometry#idm47305805107488 [sidefx.com] mentions that the VOP SOP is now hidden in favour of the Attribute VOP / Point VOP

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