Lab 3 discussion

[alexluciani]

To create the skybox I have done this method in the World class:

def create_skybox(self):
myskybox = loader.loadModel("Models/skybox.egg")  # Model filename
myskybox.setScale(200)
myskybox.reparentTo(render)

But now, to make it moves based on the camera position I tried to add this code in the update_camera function:


...
self.lasttime = task.time
self.myskybox.setPos(base.camera.getPos)
return task.cont


and I got this error:

 File "myscene.py", line 206, in update_camera
   self.myskybox.setPos(base.camera.getPos)
AttributeError: World instance has no attribute 'myskybox'


Maybe I have done some mistake with the definition of method and how to retrieve their attributes. Did someone else solve it in different way?

Thanks

[Samuele Sabbatini]

The problem is the variable myskybox!
In the function create_skybox you instanciated a general variable myskybox. But in the update_camera function you use a myskybox variable as a class variable because you use self.skybox.
So the solution depends on how you want use that variable, so you can add self.myskybox everywhere or remove "self." in the update_camera function.

I hope that this is the solution

Samuele Sabbatini

[David Sorrentino]

First, try to define the variable myskybox as CLASS VARIABLE in this way:
def create_skybox(self):
···self.myskybox = loader.loadModel("Models/skybox.egg") # Model filename
···self.myskybox.setScale(200)
···self.myskybox.reparentTo(render)
Then, update the position of the skybox within the method update_camera in this way:
self.myskybox.setPos(base.camera.getX(), base.camera.getY(), base.camera.getZ())

A class variable is a variable that you can access from every method of the class. You can define a class variable putting the code
self.
before the variable in question.

Cheers,
David

[alexluciani]

Thanks to all, I have got it, in python without the prefix "self.", passed as parameter, a variable remains local to the method or class.

Cheers,
Alex