I don't quite understand the difference between the two types of VTK files. I know that there is a simple legacy format and an XML format, but how can you tell the difference between the two? This helps and I think it gives me a good understanding of the legacy format, but the XML format is more elusive to me.
The reason that I'm curious about this is because I'm using three.js to load objects and there are some files that I can get to work, and others that don't. I believe I have the legacy format working but I'm a little confused because it seems the non-working file has the same format as the working one. Just the fact that it doesn't work leads me to believe it is the XML format, but I'm not sure.
To summarize my questions:
Is there an explicit difference between legacy and XML VTK files?
When using three.js, do I need to establish a method of differentiating the two and having two ways to load the respective formats?
If you need to see any code, let me know! Thanks. :)
As you said, the new format is an xml format. If you open the file with a text editor, you should see the tags. Also, usually the extension .vtk is for legacy format, and extensions .vti, .vtp etc are for the new format ( see pag.12 of the document you linked). If you want to check also how the file should look like, you could try to open it from a gui like Paraview or Slicer (or use the vtk distribution in c++ or python).
Looking at the example on the three.js website, I have the impression that it supports only the old format.