034 – Constraints

I have been playing around with constraints inside Houdini.

Cone twist constraint.


Using the sop solver, you have a bunch of flexibility.

Screen Shot 2016-07-02 at 4.16.49 PMScreen Shot 2016-07-02 at 4.17.04 PM

Here I’m deleting constraints when their angle its greater than 0.1

if (@angle > 0.1)  removeprim(0, @primnum, 0);

Screen Shot 2016-07-02 at 4.17.20 PM

cone_const_wall_02 (1)cone_const_wall_03 (1)cone_const_wall_04cone_const_wall_05

Here are some tests using the glue constraint


Screen Shot 2016-07-02 at 4.02.24 PMScreen Shot 2016-07-02 at 4.03.29 PM



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.


10 thoughts on “034 – Constraints”

    1. 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.


    1. 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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