I have been playing around with constraints inside Houdini.
Cone twist constraint.
Using the sop solver, you have a bunch of flexibility.
Here I’m deleting constraints when their angle its greater than 0.1
if (@angle > 0.1) removeprim(0, @primnum, 0);
Here are some tests using the glue constraint
And using multiple types of constraints (spring and glue ) in the same object.
But you can get interesting results using just the active attribute without any constraints.
Let's Houdini 
I am having problem when adding the Sop Solver.
when i add the sop solver to the cone constraint network, everything will just fall down.
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Hey Hans, hard to tell without looking at your scene. Upload it when you get a chance so I can take a look.
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Wow that would be great. awesome
I also realize when adding a Sop solver all the parameter i used to see on the geometry Spreadsheet under Constraintnetwork -> Geometry just disappears
Scene link : https://drive.google.com/file/d/0B096WyAFRC1GYVdmSzZ6UHc2VFE/view
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Hey Hans,
Just make sure to change the display tag from the dop_geometry to your wrangle inside the sop solver, so the solver can cook the wrangle. Also, In the Cone_con, change the “Overwrite with SOP” to 0. Here’s the scene https://www.dropbox.com/s/gcba6au34b4d7dk/Hansi_wood.hipnc?dl=0
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wowThanks alot victor. This page is very usefull . Keep it up
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hey victor. Its just an idea but is it possible to orient the all the Goal and Constrained Axis in the Cone Twist Constraint Relationship for each Geometry i copy on a Spere like in this Scene ?
https://drive.google.com/file/d/0B096WyAFRC1GVmxSS2s3cHZoN3M/view
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You need to set the attributes the cone constraint need to orient the cones equal to your normal attribute.
Try this using an attribute wrangle an run it over points
v@goal_twist_axis = @N;
v@constrained_twist_axis = @N;
Then make sure to promote those attributes from points to primitives.
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It worked very well. Thank you for taking the trouble to help me. I do appreciate it.
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heyy guys i just cant figure out why my geo is always exploding when using the Hardconstraint to attach to diffrent geo together. I have even reduce the Rest length to 0 but its still exploding.
Scene : https://1drv.ms/u/s!AvYMWljZePaagziqm6ZFDdWmnJkL
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Just make sure the points connecting different pieces are in the exact same position, otherwise when you play the simulation the points will try to snap together causing your geo to explode.
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