I thank you very much for your very complete and quick answer.
I find that I still have to learn a lot.
I will analyze and try to understand, to implement all your information.
I take note of your remarks and I will try to be as complete as possible in my next post
In Sketchup with the geoposition option, I created a rectangle with juxtaposed images. All images have been unlocked and exploded to form a single entity.
The .SKP file has been exported to DAE file for use by modelconverterX (resized) and creation .BGL and .BMP are ok.
My problem: when...
my ground line is only visible when the plane is close to the line. Too far the intensity of the line is at 50% and improves as the plane approaches the line. Can you tell me where is my mistake or have a solution ?