Re: [Closed REQ 6152]: OOGL->VRML

[daemon]

There were some problems with the OOGL file.  When I run oogl2vrml on the
file you sent, I get some errors, and it produces nothing much for output:

#VRML V1.0 ascii
Separator {
 ShapeHints {vertexOrdering COUNTERCLOCKWISE faceType CONVEX}
} # end final Separator

Note that this is version 1.0.  VRML viewers tend to be finicky about the 
type of input they accept; some may only accept VRML 2.0, even though
(as far as I know) VRML 2.0 is a superset of VRML 1.0.
SGI supplies a /usr/sbin/vrml1ToVrml2 converter, though I don't know whether
it has to do anything more than change the header line.

But back to the original OOGL data file...

  - although it's sometimes accepted for backward compatibility,
    OFF objects really need to begin with the keyword "OFF", as in

appearance {
     material {
                        edgecolor 1.000000 0.450000 0.000000
     }
}
OFF
8 6 0
-74.000000 1.000000 -35.833332
-74.000000 5.000000 -35.833332
-74.791306 1.000000 -35.833332
-74.791306 5.000000 -35.833332
-75.208694 1.000000 -36.166668
-75.208694 5.000000 -36.166668
-74.000000 1.000000 -36.166668
-74.000000 5.000000 -36.166668
4 0 2 3 1 1.000000 0.450000 0.000000 1
4 7 5 4 6 1.000000 0.450000 0.000000 1
4 0 2 4 6 1.000000 0.450000 0.000000 1
4 1 3 5 7 1.000000 0.450000 0.000000 1
4 0 1 7 6 1.000000 0.450000 0.000000 1
4 4 5 3 2 1.000000 0.450000 0.000000 1

Without the OFF keyword, they can be recognized as another kind of object
(TLIST), which screws everything up.

  - In two places, the file contained some very funny-looking numbers:

	-74.791306 5..000000 -35.833332

	-78.573952 9.000000 -34..621883

    These weren't detected as errors; "5..000000" gets parsed as *two*
    valid numbers, "5." and ".000000".

  - In several places where lines got long, apparently the software writing
    the file decided to split the line, and got things like

74 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110 112 114 116 118 120 122 124 126 128 130 132 134 136 138 140 142 144 146 0.000000 1.
000000 1.000000 1

    Note the line broken after the "1."; this confused things, too.

When I fix all of these, I get something that looks reasonable
(though it's a bit hard to find in the WebSpace viewer, as it's not
near the origin, and oogl2vrml doesn't try to add an initial viewpoint).
I didn't have to use vrml1ToVrml2 -- WebSpace accepted the VRML 1.0 file.

I've put up the fixed-up OOGL file as
	http://www.geom.umn.edu/~slevy/sowsy.oogl
and the corresponding VRML 1.0 file as
	http://www.geom.umn.edu/~slevy/sowsy.wrl

(they're not linked into my page, you'll just need to use the URL's).


  Stuart Levy