1. Introduction and File Formats

SPIERSview is a stand-alone program for viewing and manipulating of three-dimensional models. It understands five different file formats, the first four of which it can also output:

1. Compact SPIERSview files (.spv file extension). These are very small in size and intended as a practical way of distributing models over the internet; they can however take a long while to load as the software must compute isosurfaces for all objects. SPIERSedit generates files in this format.

2. Presurfaced SPIERSview files (.spv file extension). Presurfaced spv files allow SPIERSview to skip computation isosurfaces on loading; they hence normally load substantially quicker. They are, however, typically around an order of magnitude larger than compact files, and are hence impractical for moving over the internet. Presurfaced files are generated by SPIERSview itself.

3. Finalised SPIERSview files (.spvf file extension). Finalised files load very quickly, but are even larger than presurfaced files. They are ‘locked’; when a user loads a finalised file, SPIERSview enters a stripped-down view-only mode (finalised/VAXML mode), in which the model cannot be altered. Use finalised files to produce ‘finished’ versions of models for viewing by other workers, or as teaching tools.

4. VAXML datasets (.vaxml extension). VAXML (Virtual Anatomy XML) is intended as a simple interchange format for virtual anatomy (palaeontological or biogical) datasets. VAXML datasets use one or more STL or PLY files to define the geometry of objects that comprise the dataset, together with one VAXML file that provides data on the dataset as a whole, and specifies how the STL or PLY files are to be assembled. If PLY files are used, geometries incorporating surface colour information (e.g. from laser scanners) can be imported. SPIERSview can generate VAXML/STL datasets from compact or presurfaced SPIERSview files (.spv extension). SPIERSview loads VAXML datasets in the same stripped-down view-only mode (finalised/VAXML mode) as it uses for finalised files (.spvf); the latter are little more than combined and compressed combinations of a VAXML file and STL object geometries.

5. SPIERSview metafiles (.sp2 extension). These are a legacy mechanism from earlier versions of SPIERSview for combining .spv files together; while SPIERSview can still read them, no currently maintained software generates them.