WorldViz User Forum  

Go Back   WorldViz User Forum > Vizard

Reply
 
Thread Tools Rating: Thread Rating: 8 votes, 5.00 average. Display Modes
  #1  
Old 09-05-2012, 09:58 AM
shivanangel shivanangel is offline
Member
 
Join Date: Feb 2006
Location: New Jersey
Posts: 182
Question Properly handling Inheritance of VizNode and using copy

Hello Vizard support.

I had a question on how to properly implement the <viz.VizNode>.copy method when using inheritance.

I have created several class that inherit from VizNode, however they have their own __init__ functions that take in additional parameters beyond what VizNode might utilize.

When I create a copy of these objects using the original copy method provided by Vizard, I get an error that indicates I am not getting the correct number of parameters into the class __init__ method I created.

When I looked at how copy was implemented, it looks like you return an instance of self.__class__(Vizard Stuff In Here) when I call copy.

Below is my __init__ method, as you can see I take in an additional template parameter.

Code:
class GreenObject(Model3D, Properties):
	def __init__(self, modelString, GOTemplate):
		Model3D.__init__(self, modelString)
		
		self.publicVariables = []
	
		self.variableValues = [0.0] * len(GreenObject.properties2Indices)
		
		self.greenObjectTemplate = GOTemplate
If possible, I would like to call the original copy functionality along with doing some copying of my own when <*>.copy is called.

Normally, I would just call the base classes version then add my own code. But I don't know much about what VizNode is doing behind the scenes and I figured you'd have a better idea on how to handle this.

Thanks,
George
Reply With Quote
  #2  
Old 09-05-2012, 11:55 AM
farshizzo farshizzo is offline
WorldViz Team Member
 
Join Date: Mar 2003
Posts: 2,849
Your example code does not show how the node object is created. Is it passed to your class, or is it created within the __init__ of your class?
Reply With Quote
  #3  
Old 09-05-2012, 12:17 PM
shivanangel shivanangel is offline
Member
 
Join Date: Feb 2006
Location: New Jersey
Posts: 182
Sorry, forgot to include that class as well.
Here is a super class of GreenObject called Model3D which derives
from viz.VizNode

Code:
class Model3D(viz.VizNode):
	
	GORM = None
	
	def __init__(self, string):
		
		#Typical string entry
		if type(string) == str:
			base = viz.add(string)
			viz.VizNode.__init__(self, base.id)
				
		#Use for on-the-fly creation in Vizard
		elif isinstance(string, viz.VizNode):
			base = string
			viz.VizNode.__init__(self, base.id)
				
		elif isinstance(string, int): #We are dealing with a copy that has passed in an id number
			viz.VizNode.__init__(self, string)
			
		
		else:
			print 'Copy type', string, type(string)
Reply With Quote
  #4  
Old 09-05-2012, 02:12 PM
farshizzo farshizzo is offline
WorldViz Team Member
 
Join Date: Mar 2003
Posts: 2,849
The node.copy command will pass all extra keyword arguments to the class __init__ method. You can override the copy method in your class and have it pass all the required arguments as keyword arguments to the underlying node.copy method. Example:
Code:
import viz
viz.go()

class MyNode(viz.VizNode):

	def __init__(self, model, parameter):

		if isinstance(model,basestring):
			base = viz.add(model)
			viz.VizNode.__init__(self, base.id)

		elif isinstance(model, viz.VizNode):
			viz.VizNode.__init__(self, model.id)

		elif isinstance(model, int):
			viz.VizNode.__init__(self, model)

		self._parameter = parameter

	def copy(self, parameter):
		return viz.VizNode.copy(self,parameter=parameter)

node = MyNode('gallery.osgb',0)
nodeCopy = node.copy(1)
Does this work for you scenario?
Reply With Quote
  #5  
Old 09-06-2012, 06:56 AM
shivanangel shivanangel is offline
Member
 
Join Date: Feb 2006
Location: New Jersey
Posts: 182
I believe it will work.
I'll create a new instance of the class in the copy constructor and pass the copy into the initializer.

This way the copy command will now not just copy viz.VizNode but I can code it to also copy the rest of the parameters I've attached to my new class as well.

Thank you,
George
Reply With Quote
Reply

Tags
inheritance, viznode

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 04:39 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright 2002-2023 WorldViz LLC