Re: relative URLs VRML viewed from HTML-browsers
Mike Heck ([email protected])
Fri, 12 May 95 08:36:07 -0700
> Relative URLs in a VRML scene get resolved with respect to the local temporary
> file if webspace is fired from netscape following a link to a VRML document.
> Thus, it is necessary to go within webspace directly to the respective URL if
> one wants to follow links in the scene.
>
> This is of course a specification and protocol bug, not one in webspace.
> Nevertheles, this needs to get fixed urgently.
>
> An information in the VRML document parallel to the HTML <BASE> tag would
> do the fix.
>
> Consider for instance the following convention to define an Info node tagged
> BASE, whose string field contains the BASE URL of the document (i.e. the URL
> relatively to which all relative URLs in the document are resolved):
>
> DEF BASE Info {
> string "http://www.artcom.de/vrml/welcome.wrl"
> }
>
> Then a WWWAnchor like
>
> WWWAnchor {
> name "next.wrl"
> }
>
> would point to the right URL http://www.artcom.de/vrml/next.wrl even if
> webspace got the document from a temporary file created by e.g. netscape
> following a link to the above mentioned URL (which is, by the way, not yet
> active).
>
> Such a mechanism should get into the final VRML/1.0, if still possible.
Yes!
This is an extremely important issue for VRML browsers to work well and
to work with as many different HTML browsers as possible.
I don't know if I'd call it a "specification and protocol bug", but the
bottom line is that most HTML browsers do not pass the URL when they
start a helper application (like WebSpace) -- they only pass the local
filename. So if you kick off WebSpace by selecting a VRML link in an HTML
document, you're likely to be out of luck when it comes to following VRML
links specified with relative URLs, because WebSpace (or whatever) doesn't
know the base URL for the VRML document.
We should at least encourage all VRML authors to adopt this convention,
and I think it would make sense to add a section on "standard hints" to
the VRML specification document.
-Mike
[email protected]