Here’s a simple Python snippet that shows how to traverse the object hierarchy to get at a Texture Projection Definition. Note that I’m not looping over any of the collections, I just get the first element with “(0)” on lines 25, 28, and 31.

#
# 2013 SP1 shortcuts
#
#from sipyutils import si			# win32com.client.Dispatch('XSI.Application')
#from sipyutils import siut		# win32com.client.Dispatch('XSI.Utils')
#from sipyutils import siui		# win32com.client.Dispatch('XSI.UIToolkit')
#from sipyutils import simath	# win32com.client.Dispatch('XSI.Math')
#from sipyutils import log		# LogMessage
#from sipyutils import disp		# win32com.client.Dispatch
#from sipyutils import C			# win32com.client.constants
#si=si()


si=Application
dict=si.Dictionary

def dispFix( badDispatch ):
	import win32com.client.dynamic
	# Re-Wraps a bad dispatch into a working one:
	return win32com.client.dynamic.Dispatch(badDispatch)

o = dict.GetObject( "grid1" )

# Get the texture coordinates (aka the Sample cluster)
c = o.ActivePrimitive.Geometry.Clusters.Filter( "sample" )(0)

# Get  the Texture Projection
uv = c.Properties.Filter( "uvspace" )(0)

# Get  the Texture Projection Definition
uvdef = uv.NestedObjects.Filter( "uvprojdef" )(0)
print si.ClassName(uvdef)

# Get a texture projection parameter (in this example, the U translation)
x = dispFix(uvdef)
projtrsu = x.Parameters("projtrsu")

print si.ClassName( projtrsu )
print projtrsu.FullName

Here’s what the hierarchy looks like in the SDK explorer: