Table 1.

Glossary of terms

3D‐reconstruction	The process of converting raw image projections (e.g., from X‐ray computed tomography) into cross‐sectional stacks of images, which resemble traditional tomographic sections.
3D‐surface mesh	A series of 2D polygons (typically triangles or quadrangles) linked together to recreate the surface of a 3D‐object. This format is required for creating the interactive 3D‐PDFs described in this article, and for 3D‐printing.
Computed tomography	Commonly known as CT or ‘CAT’ scanning, a process for virtually recreating a three‐dimensional object from a series of sequential, cross‐sectional image slices, traditionally with microtome sectioning, but now more commonly with X‐ray imaging.
Projections	The raw images recovered from X‐ray CT imaging as the X‐ray source and camera rotate 360° around the subject (or the subject rotates as in μCT scanners). A higher number of projections results in a smaller angle between each projection, and therefore less noise in the reconstructed 3D‐image (but also a longer acquisition time).
Rendering	The process of adding colours, textures and lighting to a 3D‐object, which then determine the appearance of the final image or ‘render’. When imaging biological specimens, lighting is particularly important for visualising the true textures (e.g., from X‐ray CT) and colours (e.g., from photogrammetry) of the subject.
Rigging	The process of adding a virtual ‘skeleton’ to a 3D‐surface mesh in order to articulate joints and move or animate sections of the mesh independently. Used in this article to virtually reposition the mandibles of a scanned insect.
Segmentation (of 3D‐data)	The process of separating different regions of volumetric or surface mesh‐based 3D‐data. Typically used to aid visual differentiation, or for animation, but now also particularly useful for virtual dissections of internal morphology of invertebrates, which cannot easily be isolated by adjusting the visible range of densities (as one would for a vertebrate skeleton).
Volumetric 3D‐data	A cloud of ‘voxels’ (three‐dimensional pixels) that make up a virtually reconstructed 3D‐object generated by X‐ray CT scanning or similar, where each voxel contains information about the opacity of the original material (e.g., X‐ray absorption), thus providing measurable volumetric data of any part of the object.