setBackgroundImage not working as expected

[Andrea]

Hello everyone,

I am using quite recent versions of Sofa and SofaPython3 (December 2020) and the function setBackgroundImage is not working as before.

In python, when I run:

import Sofa.Gui
Sofa.Gui.BaseGUI.setBackgroundImage("image.png")

I get the following error:
TypeError: setBackgroundImage(): incompatible function arguments. The following argument types are supported: 1. (self: Sofa.Gui.BaseGUI, arg0: str) -> None

Does anybody know how can I fix this?

Thanks
Andrea

[jnbrunet]

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

[Andrea]

Hey JN,

Thanks for your reply.

I also tried that, but Sofa.Gui.GUIManager.GetGUI() returns None. Yet I have initialized the GUIManager by doing:

Sofa.Gui.GUIManager.Init("scene", "qglviewer")
Sofa.Gui.GUIManager.createGUI(root)
Sofa.Gui.GUIManager.MainLoop(root)

Andrea

[jnbrunet]

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

[Andrea]

Hey JN,

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<code>and there is no background image. 

But this time, current_gui is not None 🙂

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

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
`

I both checked the existence and accessibility to path_to_my_image/img.png and to /home/andrea/Projects/sofa/share/textures/SOFA_logo.bmp

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

Andrea

[jnbrunet]

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

[Andrea]

It works!!! Thank you so much JN!!

[Author]

Posts