Re: LANG: Text in VRML

steve (STEVE@division.demon.co.uk)
Mon, 27 Feb 1995 09:59:11 +0000


Hi.

I'm new to the VRML list, but seem to have joined at an
interesting time. I am Steve Ghee, Technology Director at Division
Ltd. I wrote the original dVS system, and am now charged with
defining future VR technology (software and hardware) here at
Division. I hope I can contribute....

> Yes, TEXT is undoubtedly a major oversight :-o, for the following reason; we
> need to have a standard methodology in place for the display of text data
> inside of VRML worlds. Without this standard there's no guarantee that a
> VRML environment will look the same from one browser to another. That would
> be bad.

I have to say that in my experience with VR worlds, most people do
not really care on the exact representation of text, just the
message it is getting across - "please close the door" works just as well
in serif and sans serif fonts! Of course, you could get reallly
pedantic and say "well I want my text sign above my virtual shopping
mall to look exactly like my company logo" - well in that case, design
it as a polygon mesh.

I would agree with earlier mesages on the subject - defining text as
a string that local browsers can interpret according to local
resources is the way to go - a standard set of font's should be
supported by browsers, and for those fonts not supported, some
default font should be used.

The text string is specified from a standard character set (ASCII ?),
and control characters (e.g. \n) allow multi-line display.

[Using texturing to display text is not on - "texturing for free" was
one ammusing comment I saw. Software renderers may be able to suport
'unlimited textures' per view, but not exactly 'real-time'. Hardware
renderers have limitied texture RAM and this is generally like
gold-dust.]

Text objects should be treated as other objects within the system -
position/orientation/scale, color, texture etc. Billboarding is a useful technique
to ensure object always face the viewer (useful for object annotation etc.).
Problem is how this works in a multi-user scenario. Anyone have any
useful suggestions here?

As for text being viewable from behind, this is simply a material
assignment issue - Division's VR systems allow (different) material properties
to be assigned to either/both front and back faces of Objects (and
text is just another Object). If material properties are not supported, then at
least a flag detailing "double_sided" would do. Is is then up to the author to
decide how the text should be viewable

>>-------------------------------------<<
Steve Ghee ( steve@division.demon.co.uk )
Director of Technology

Division Ltd
19 Apex Court
Woodlands
Almondsbury
Bristol, UK
BS12 4JT
Tel : +44 1454 615554
Fax : +44 1454 615532
>>-------------------------------------<<