Jo Plaete

Visual Effects – 3D – Interactive Design

ICE Kinematics Helper Operator

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Quick post to share something possibly useful when you’re working with Softimage and ICE.

As known ICE is currently still limited to pointclouds/particles only and doesn’t officially support the setting of kinematic properties on objects in your scene yet (reading them works). This could come in handy when using ICE for things like rigging, etc. You can play already with this by enabling a variable in your xsi env.
set XSI_UNSUPPORTED_ICE_KINEMATICS=1 , more info about this:
For the official support we’ll have to await a future release, maybe Softimage 2011 (?)

In the meantime, if you do want to get some ICE data to drive object kinematics without enabling the unsupported feature, this operator might help you with that.

What it basically does is reverse the process, instead of writing position and rotation data from the ICEtree onto the object’s kinematics the c++ operator will sit on the object and query those attributes from the pointcloud’s data array. This way the object will constantly update it’s position and rotation mimicking the behaviour of a certain point in your pointcloud. Back in ICE you can do whatever you want with the point/particle including reading kinematics from other objects in your scene, etc.

I’ve compiled the operator for both Softimage 7.x and 2010 64Bit (windows)
link 7.x
link 2010

What do you need ?
1. a pointcloud with at least 1 point
2. an object
3. the ICEkine operator installed (just load it as a usual plugin/put it in your workgroup)

How does it work ?
To bind the operator to an object use the following bit of python code which:
1. finds and defines both the pointcloud and the object
2. applies the operator

# Add/Find object (e.g. Null) / Find object
myObject = Application.ActiveSceneRoot.AddNull( "null" )
# myObject = Application.ActiveSceneRoot.FindChild( "myObject" )
# Provide the pointcloud primitive ( .ActivePrimitive ! ) you want to remap from
pointcloudPrim = Application.ActiveSceneRoot.FindChild("pointcloud").ActivePrimitive
# Bind The Opertor to Global or Local Kinematics
op = Application.AddCustomOp( "ICEkine", myObject.Kinematics.Global, [pointcloudPrim], "ICEkineOp" )

Once this has successfully connected you should find your object traveling along with the first point in your pointcloud. To connect the operator to another point of that cloud you can open up the operators property page and specify your desired point ID. Don’t forget to initialize self.Orientation on your cloud as the operator will look for it to drive the rotation.

As far as performance goes I get 100 objects remapped running still at 60fps (on my laptop) so for remapping ‘a few nulls’ it should be alright.

Again, this is just a temporary helper but it might be useful until the ICE kine beast itself is unleashed, use at own risk.

Pls let me know how you get on it with it, especially in the (unlikely;) case of buggy behavior. I used it for a few applications/test and it worked fine for me so far, also gotta thank my friend Nic Groot Bluemink for testing it !

have fun !



Written by Jo Plaete

December 12, 2009 at 4:06 pm

Posted in 3D, animation, scripting, TD, XSI

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