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VRML97 Tips 595
5.
Open the VRML97 file in the browser and test
it.
Inter face
The VRML97 exporter suppor ts the following:
Lights—Al l VRML97 light types: direct, omni, and
spot.
Came ras—Free and targeted cameras.
Primitives—Sphere, cone, box, and cylinder
primitive objects. These objects export as
VRML97 primitive objects. This helps reduce the
size of VRML97 files.
Animation—All position, rotation, and scale
animationonobjects,aswellasanimated
hierarchies, inverse kinematics, and all controller
types. Select Coordinate Interpolators (page 3–591)
in the Export dia log to export animated meshes,
such as an animated B end modifier or character
studio Physique animations.
VRML97 Tips
The following tips will help you make your work
look as good as possible and display and move as
fast as possible.
Geometry
Usesmalltexturemaps,andusethemsparingly.
Keep t he polygon count of your objects d own
to achieve good p erfor mance. Acompletescene
w ith a maximum of 5,000 to 10,000 polygons is
manageable for most computers. The Level of
Detail (page 3–602) helper lets you manage the
polygon count of objects in the scene. You can also
use the software’s Opt imize modifier to simplify
objects before exporting them to VRML97.
Use primitives whenever possible. For example,
a scene containing only a sphere exports to a
VRML97 file of about 400 bytes, but if you apply
an edit mesh modifier and move one ver tex on the
sphere, the VRML 97 file is about 7 ,400 bytes.
Use Sh ow Statistics (page 1–1253) to keep track
of the number of f aces in your scene.
Call your VRML97 .wrl files from a standard
HTML page and constrain the v iewer to a limited
window on the screen using the embed command.
This decreases the number of pixels that must be
rendered on every frame and makes the VRML97
environment more responsive. Many users use
high resolution (800x600 or more), so the number
of pixels during rendering and navigation can
belargeandthevideodisplaymayslowdown.
Frames may be dropped as the browser attempts
to keep up its real-t ime rendering, and navigating
the scene will become "chunky.” Use the embed
command to avoid this, for example, <embed
SRC=myworld.wrl WIDTH=300 H EIGHT=200>
Hidefacesonanobjectinthesoftware,then
export t h e obj e c t. The hidden faces appear as a
hole in the object. While the VRML97 plug-in can
export hidden objec ts, it does not export hidden
faces. Hide faces that you know will never be
visible in the scene, such as the b acks of objects or
the bottom faces of object s rest ing on a surface.
Use i nst a nces to reduce file size for objects that
havethesamegeometry.
Whenever you use a Mirror t r a ns for m , us e t h e
Reset Transform utility immediately aft erward.
You can also use a Normal modifier immediately
followed by Unify Normals. VRML97 does not
allow mirror transforms (negative sca les). The
Reset Transform utility modifies the data in the
actual mesh object to create the mirroring effect.
Don’t change units when modeling for VRML97.
To model in meters, keep the units set to the
default and use one world unit as one meter.