The kindly Rev. overheard pet### [at] usanet (Peter Popov) saying on
21 Oct 2000: 

>>The .wrl file format is for Virtual Reality Modeling Language
>>(VRML).  It's a text format (to be specific, UTF8).
>
>I know, I've played with it a little.

I'll say you have!  Christ, why didn't you tug on my coat or something?  
Sorry, Peter, I must be growing senile.

>Warp's compressed mesh is just what you described - vertex
>coordinates, normals, vertex & normal indices and then UV coordinates
>(if necessary), all in plain vanilla ASCII.

I found the URL in the backlogs of p.b.utilities, so I'll check it out.  
Looks like Warp reinvented the IndexedFaceSet (which also can have a 
TextureCoordinate field)!  See, I told you VRML had some good ideas.

;-)

Actually, I think either Rikk Carey (Inventor) or Eric Haines (nff) may 
have done it first.  One of these days somebody will write a history of 
3D file formats and some of us will be the only ones who buy it.

Speaking of 3D file formats, I've been into the innards of .3dmf 
recently.  Does somebody want to tell me what the heck the edges are for 
in the TriMesh?

>>As to using a cylinder to project an image on in VRML, I've seen it
>>done on the Mars Rover images, and it was awful.  You get all the
>>slow download speed of bitmap graphics *and* you get crummy looking 
>>rendering, because VRML has got to project the bits into the viewing
>>plane of the browser, which is invariably at the wrong distance and
>>at the wrong angle for them to show up very well.  Or will be, as
>>soon as the visitor to the VRML world moves.
>
>Just an idea anyway. I never said it would work like a charm :)

What makes LivePicture and QTVR work so well is that at a particular 
distance the pixels in the texture line up one for one with the pixels 
in the viewing window.  So just keep the distance fixed between the 
viewpoint and the surrounding cylinder of image (that's one reason 
you're stuck in the middle of a QTVR scene), add a little pixel blending 
to depixelate to either side of the center of the frustum, and the user 
will do the rest as he rotates to look at the area of interest.  The 
user thinks the image is sharp because he's looking at the center, which 
*is* sharp.
-- 
Rev. Bob "Bob" Crispen
crispen at hiwaay dot net

In three words I can sum up everything I've learned about life:
it goes on.

Post a reply to this message