a

This option instructs the compiler to render geometry using client vertex arrays. Geometry nodes such as IndexedFaceSet, ElevationGrid and Box can be rendered very efficiently using this feature of the GL API. Vertex, texture, normal and color information is consolidated into one global array and reused for the entire scene graph. This option can dramatically reduce the size of the compiled world, as well as (depending on the hardware) increase rendering performace.

enables vertex array support. This feature is switched 'on' by default

t

Texture data can quickly bloat the source code file into unmanageable sizes.  Since texture data is inherently static, it can be useful to have this information separated from other parts of the world definition that change more frequently.

produces two files, world.c and world_textures.c. The name of the separate texture file is always [target]_textures.c. Be sure to include both files when building the executable

g[n]

Spheres, Cones and Cylinders are rendered via OpenGL's quadric utility functions.  This value is used to determine how many slices and stacks should be used when rendering these geometries.

Default level is 10

v

Useful for support purposes

x3dsnap +v

e,w,m

During compilation, the compiler writes diagnostic information to the console in the form of errors, warnings and messages. Most errors are parsing errors caught by the compiler before the first pass of code generation begins.  If one or more compiler errors occur, the process aborts and the line number with the offending syntax is given. After parsing successfully, a scene graph data structure of the world is built internally and the first pass can begin.  The compiler "walks" the scene graph, generating code determined by the nodes encountered.  Compiler warnings are generated when a non-fatal problem is found during one of these phases. Typical warnings can include illegal polygon declarations (polygons with less than 3 vertices), resource loading errors and view frustum size limitations. Throughout the compile process, messages are fed back to the console reporting on the progress of the translation. Use the e, w, and m switches to control which diagnostic information is to be displayed or filtered 

x3dsnap +e world.wrl display compiler errors (on by default)
x3dsnap -e world.wrl suppress compiler errors

x3dsnap +w world.wrl display compiler warnings (on by default)
x3dsnap -w world.wrl suppress compiler warnings

x3dsnap +m world.wrl display compiler messages (on by default)
x3dsnap -m world.wrl suppress compiler messages