Three-dimensional OpenGL display of the current data window can be invoked with the button with symbol of cube in View button row of main window.
This feature is optional, i.e. it can be disabled at compile time. It can also happen that while Gwyddion is capable of 3D data display your system does not support it. In both cases an attempt to invoke 3D view gives an error message explaining which of the two cases occured. In the former case you have to ask the producers of Gwyddion executables to build them with 3D support or build Gwyddion yourself from source code. If it is the latter case, refer to your operating system guide on how to enable OpenGL 3D capabilities.
The 3D window has two possible forms: with basic and expanded controls. It starts with basic controls only, this form is displayed on the following figure. It can be switched to the expanded form (and back) with an expander button in the upper right corner. Clicking on the view with right mouse button brings a quick color gradient/GL material selector.
Basic 3D window contains interaction mode controls at the right side of the view. By default, dragging the view with mouse rotates it horizontally and vertically. All possible modes are listed below:
The basic controls also include an image export button.
When basic controls are shown it is possible to switch between the modes using keys R (rotation), S (scale), V (value scale) and L (light rotation).
In expanded controls the mode buttons are located in top row, however their function does not change. In addition, there are several tabs with options below them:
The 3D view can be saved into a bitmap image with the
.png still produces an image in
PNG format, albeit with a confusing extension.
Note due to the peculiarities of certain operating systems, graphics drivers and windowing environments, artefacts may sometimes appear on the exported image in parts corresponding to obscured parts of the 3D view. If you encounter this problem, make sure the 3D view is not obscured by other windows during the image export.
OpenGL material editor can be invoked with color gradient editor list and the material management works identically. The actual editor is of course different. It allows to edit four quantities defining the material:→ . The controls in the material list are the same as in the
If we denote L the normal vector pointing from the observed surface point to the light source, V the normal vector to the observer, N the normal vector to the surface and R the normal vector in the direction of ideal mirror reflection, the observed light intensity in OpenGL lighting model can be expressed as
where Ia,α, Id,α and Is,α are the ambient, diffuse and specular light source intensities, respectively.