MeshViewer | A mesh viewer using Qt & VTK | 3D Printing library

It's possible the two cubes share the same mesh. In the screenshot below, there are two Blender "objects", Left-Cube and Right-Cube. Both objects use the same Blender mesh, called Shared-Cube-Mesh.

The glTF exporter recognizes this pattern and mirrors it in the glTF file. There will be two glTF nodes, corresponding to the two Blender objects that use the mesh. But there will only be a single glTF mesh, with a single cube.

You can click the "number of users" button, shown below with a white arrow pointing to it, to make the second object use its own unique mesh. But be warned, this doubles the amount of mesh data being exported to glTF in this simple example. A complete copy of the mesh would be made in both Blender and the glTF binary payload.

What the window displays is a frustum, defined by six planes. Normally, these planes are parallel, as in a cube. Anything that lies outside the frustum is not displayed.

"Zoom" may be interpreted, in a generic way, as "see bigger, nearer, more detail".

There are several ways of achieve the zoom effect:

• Scale the objects. This works, the flaw is that objects (or parts of them) may lie before the near plane or behind the far plane of the frustum.

• Move the camera towards the object. Same matter with near/far planes. Also, take care of moving through the model, you can set a "barrier" (perhaps a box) to prevent the camera moving too deep.

• For an orthogonal projection, set left/right/top/bottom planes nearer to the object. This makes the frustum smaller, thus it's normal that some objects get clipped.

• For a perspective projection you can do the same trick as with orthogonal. This trick is just to reduce the FOV (field of view) angle. If objects are too far, the perspective effect may be less obvious.

It looks like your OpenMesh library is 64-bit and you are trying to link it with a 32-bit glut library, which is not possible. You have two options:

1. Don't use glut32, and use 64-bit glut library.
2. If you need a 32-bit binary, change all your other libs to 32-bit version as well. And to run the 32-bit application on Linux (which seems you're on), you may need to add i386 architecture (see here for more info).