setBackgroundImage not working as expected

Hey Andrea,

Looking at your output, it looks like the setBackgroundImage() is looking for a BaseGui as first argument. This is similar to the “self” argument you usually find inside class methods in python. Hence this is a method which should be called from an instance of BaseGui, and not a static function that you can call directly.

Could you try the following:

# Get the current BaseGui instance
current_gui = Sofa.Gui.GUIManager.GetGUI()

# Change the background image
current_gui.setBackgroundImage("image.png")

J-N

Hey Andrea,

You need to call this function after the GUI has been created:

Sofa.Gui.GUIManager.Init("scene", "qglviewer")
Sofa.Gui.GUIManager.createGUI(root)
# ---> HERE <----
# Get the current BaseGui instance
current_gui = Sofa.Gui.GUIManager.GetGUI()

# Change the background image
current_gui.setBackgroundImage("image.png")
# ----------------
Sofa.Gui.GUIManager.MainLoop(root)

Let me know if this is working or if you face other issues.

J-N

Hey Andrea,

Well, we went a little bit further 🙂

Moreover, I need to update the background image at every time step so I will also have to call setBackgroundImage() inside my functions…

This is not a problem since the important thing is that setBackgroundImage() is called after Sofa.Gui.GUIManager.Init(). Events such as onBeginAnimationStep() are usually handled by your controller after the initialization of the GUI. You probably got the currentGui == None if you tried to get it in your createScene function since it is called before the init GUI.

Also note that if I use Sofa.Gui.GUIManager.createGUI(root) (without __file__) I get the following error:
[SofaRuntime] RuntimeError: basic_string::_M_construct null not valid

Yeah, this is already known, the second argument is mandatory and we should handle this better.

Finally,

Still not working. If I run what you suggested I get the following warning:

[SofaViewer] Could not create file ‘path_to_my_image/img.png’
Valid extensions: dds

and there is no background image.

(…)

If I only run

Sofa.Gui.GUIManager.Init(“scene”, “qglviewer”)
Sofa.Gui.GUIManager.createGUI(root, __file__)

I get a similar warning:

[SofaViewer] Could not create file ‘/home/andrea/Projects/sofa/share/textures/SOFA_logo.bmp’
Valid extensions: dds

This is because extensions other than dds (jpeg, png, tiff and bmp) are handled by the CImg plugin. Simply add a

root.addObject('RequiredPlugin', name='CImgPlugin')

In your createScene function.

Let me know how that worked out.
J-N