How to create small simple project with canvas_gl object in GTK

Hello, can somebody please help me with creating some small project with GTK and GL canvas
like this

Thank you very much

Are you planning on using horizon’s CanvasGL / Canvas3D in another project or are just looking for help with GtkGLArea? In the latter case is the better place to ask. Anyhow, you might want to have look at the GLArea example in gtk3-demo.

I didn’t found any example with opencascade and gtk expected your project.
I would like to make some .step file viewer based on your CanvasGL/Canvas3D objects.
If its possible?

I’m not using opencascade for anything other than turning STEP into a triangle mesh and exporting boards to STEP. The 3D preview itself doesn’t use opencascade, so you need to look somewhere else. Still, the example you posted isn’t really pretty as it doesn’t work with wayland and might break things such as transparent widgets on top of the 3D view as it uses the underlying window system rather than the UI toolkit for drawing.