Get and set transforms from object model using matrices

[gustavoeb]

Hi guys, I'm trying to use python to access the object model and do something I thought should be simple. I want to get the global transform and use that in my static kine state, efectivelly resetting it.
I arrived to this code. It does not return an error, but is also not doing what I expected... any ideas of what am i doing wrong?

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xsi = Application
log = xsi.LogMessage

for i in range(0,xsi.Selection.Count):
	obj = xsi.Selection(i)
	obj_kine = obj.Kinematics.Global.GetTransform2(None)
	obj_static_kine = obj.GetStaticKinematicState().GetTransform2(None)
	m1 = XSIMath.CreateMatrix4()
	obj_kine.GetMatrix4(m1)
	obj_static_kine.SetMatrix4(m1)

[xsisupport]

Yes, I'm pretty sure the GetTransform page has the answer.

Warning: The returned SITransformation object contains a copy of the transformation values, so modifying its state will have no effect on the original object. To change the object's kinematic state you must set KinematicState.PutTransform2 with the modified SITransformation object, as shown in the example below.

[gustavoeb]

Doh, that explains why nothing changes... ok changing my code here but I stumble upon yet another problem...

Do "static_kinematicstates" have this method (PutTransform2), or only "kinematicstates"?
Im getting this:

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# AttributeError: '<win32com.gen_py.Softimage|XSI Object Model Library v1.5.StaticKinematicState instance at 0x571553928>' object has no attribute 'PutTransform2'

when running this code:

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for i in range(0,xsi.Selection.Count):
	obj = xsi.Selection(i)
	
	obj_kine = obj.Kinematics
	obj_statickine = obj.GetStaticKinematicState()

	global_transform = obj_kine.Global.GetTransform2(None)
	static_transform = obj_statickine.GetTransform2(None)
	
	m1 = XSIMath.CreateMatrix4()
	global_transform.GetMatrix4(m1)
	static_transform.SetMatrix4(m1)

	obj_statickine.PutTransform2(None, static_transform)

ps: thanks for helping out ;)

[xsisupport]

I don't see PutTransform for StaticKinematicState in the docs, so you may need to resort to JScript (or VBScript) to set the transform.

[gustavoeb]

Will try that. Thanks again Mr. Blair!

[EricTRocks]

I know for a fact you can set the static_kinestate property without having to resort to jscript or vbscript. I think you can just use the .Transform to set it using a transform created from XSIMath.CreateTransform() that is filled by the GetTransform2() from your object. I just did this last week. Unfortunately I'm away from that code this weekend. Can post some on Tuesday if you haven't figured it out by then.

pseudo code:
myObjXform = myObj.Kinematics.Global.GetTransform2(None)

xform = XSIMath.CreateTransform()
xform.PutTransform2(None, myObjXform) # might need to use another method? Maybe .Copy() instead.
staticKine.Transform = xform

[gustavoeb]

works a treat using Copy method Eric!
here is the working code:

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	for i in range(0,xsi.Selection.Count):
			obj = xsi.Selection(i)
			if obj.HasStaticKinematicState():
				#get kinematic and static kinematic states
				obj_kine = obj.Kinematics
				obj_statickine = obj.GetStaticKinematicState()
				
				#get a copy (not actual transform) from global transforms
				global_transform = obj_kine.Global.GetTransform2(None)
				
				#copies global transform values to a newly created sitransform object
				t1 = XSIMath.CreateTransform()
				t1.Copy(global_transform)
				
				#sets transform attribute
				obj_statickine.Transform = t1
			else: log(str(obj) + ' has no static kinematic state.')