CC3+ contains a huge amount of various commands and features. This series highlights a number of these. There won't be any special progression to this series, and the command will be selected from the entire range, from the simple basic commands, to more advanced features intended for the more advanced users. Feel free to use this topic to discuss the command presented.
This series is called the command of the week, but it could also explain a feature. The explanations will tend to explain the technical parts of the command, and is intended to highlight the basics (and complexities) of the command, and information about how to use it, but won't be a detailed tutorial. It is up to you to use it creatively in your maps.

Week 31 - Convert File

While files in CC3 format works fine in CC3+ too, there are some differences that causes them to not perform optimal, and that is the path names to the resources. CC3 used to keep all raster resources in the CC3 installation folder, which we usually refer to by the # symbol. In CC3+, everything is in the data directory instead, which we use @ to refer to, while # still refers to the installation directory. CC3+ has a fallback, so if it doesn't find the file it is looking for in the Installation (#) directory, it looks in the data directory (@) instead. However, this fallback doesn't work with the multi-resolution system CC3(+) employs, meaning that CC3+ will load these resources in one resolution only, which usually means that CC3+ will only load the highest resolution resources, hurting performance, or only the lowest level resources, causing a very low-quality look. For this reason, it is best to convert the map to CC3+ format.
The Convert File command also take care of converting absolute paths to relative ones where possible, which is also quite helpful.
Warning: Files converted to CC3+ format this way will not work in CC3 afterwards, as CC3 doesn't understand the @ reference, so don't convert old files you still want to use in CC3.
New files created in CC3+ doesn't normally need conversion, but some bugs in older unpatched symbol catalogs may have led to CC3+ maps with #-references, so sometimes it is helpful to run on existing CC3+ maps too.
For more about absolute and relative paths, and the #, @ and $ references, check the 'File Paths' command of the week entry.

Where to find it?

Command Line: CURFILECONVERT (Alias: FFIX)

How to use it?

Simply open up the map to convert, and type the command on the command line. This will bring up a window with a list of all the file paths that were converted in the map. This includes paths to symbol images, paths to bitmap fills and paths in hotspots and map notes. It converts all #-references to @-references, and changes absolute paths to relative paths, using @ and $, whatever is appropriate.

Related commands

You can also convert multiple files with the MULTIFILECONVERT (MFFIX) command. This command converts all the maps in a specified directory, including subdirectories.

Also, if you have old CC2 maps, these won't benefit much from this command, instead, use CC2 to CC3 conversion (LYRTOSHTD) in the File menu for this task. This moves entities to appropriate sheets based on their Layer and does most of the grunt work of bringing the old CC2 map into CC3+ state. Note that this doesn't update the style of the map, it will still be in the CC2 Pro vector style. The intent of the command is primarily to set up sheets correctly and place the entities on these sheets, enabling you to use effects and such in the map.

Missing resources

It is worth noting that this command doesn't magically find missing resources. If you have red X'es in your map before running this command, they will still be there afterwards.