hwI3DViewCtrl ArcBall

This command allows you to rotate the model by manipulating a virtual sphere. When the command is first executed, it waits for the cursor to move into the graphics area. The left mouse button can then be pressed and moved to rotate the model, the middle mouse button can be used to change the center of rotation by clicking on the model, and the right mouse button can be used to cancel the operation

hwi OpenStack;
    variable t [expr rand()];

    catch {
        hwi GetSessionHandle sess$t;
        sess$t GetProjectHandle proj$t;
        proj$t GetPageHandle page$t [proj$t GetActivePage];
        page$t GetWindowHandle win1$t 1;
        page$t GetWindowHandle win2$t 2;
        win1$t GetViewControlHandle vc1$t;
        vc1$t ArcBall;
    }
    hwi CloseStack;