Hi all,

I am new to MRIcroGL and I think it's a great software. However, I am facing a problem at the moment. I'd like to add 3 different overlays to the 'mni152_2009bet' image and I'd like the first two to have a transparency of 50% (so that It would be possible to see the brain underneath), while I'd like the third and last overlay to have 0% transparency so that it's not possible to see the tissue underneath.
I've tried to do it manually and also with a script, but I've failed. Could you please tell me how to do it?

Thanks,

Nico

You will want to open the scripting window and use the function
  overlaylayertransparencyonbackground()
the implementation of this function has changed a little bit, but the attached image is generated with v1.0.20180622 using this script

begin
resetdefaults;
backcolor(255, 255, 255);
loadimage('mni152_2009_256');
//1st overlay, 50% = translucent
overlayload('motor');
overlayminmax(1, 2.6, 2.6);
overlaylayertransparencyonbackground(1, 50);
//2nd overlay, 50% = translucent
overlayload('motor');
overlayminmax(2, -2.6, -2.6);
overlaylayertransparencyonbackground(2, 50);
//3rd overlay, 0% = opaque
overlayload('motor');
overlayminmax(3, -6, -6);
overlaylayertransparencyonbackground(3, 0);
//display
mosaic('A H -0.2 -24 -16 32 50 60 S X R 0');
end.

or if you prefer Python:

import gl
gl.resetdefaults()
gl.backcolor(255, 255, 255)
gl.loadimage('mni152_2009_256')
#1st overlay, 50% = translucent
gl.overlayload('motor')
gl.overlayminmax(1, 2.6, 2.6)
gl.overlaylayertransparencyonbackground(1, 50)
#2nd overlay, 50% = translucent
gl.overlayload('motor')
gl.overlayminmax(2, -2.6, -2.6)
gl.overlaylayertransparencyonbackground(2, 50)
#3rd overlay, 0% = opaque
gl.overlayload('motor')
gl.overlayminmax(3, -6, -6)
gl.overlaylayertransparencyonbackground(3, 0)
#display
gl.mosaic('A H -0.2 -24 -16 32 50 60 S X R 0')