What is VRML

1
What is VRML?
VRML (Virtual Reality Modelling Language) is a
hierarchical scene description language that
defines the geometry and behaviour of a 3D scene
or "world" and the way in which it is navigated
by the user. VRML world files have the file
extension .wrl (or .wrz for gzip compressed
files) and require either a stand-alone
application or web browser plug-in to be viewed.
2
VRML File Structure

• A VRML file always starts with the header
•   VRML V2.0 utf8 
• After the header the following can appear 
• nodes 
• prototypes
• routes
• The color model used is RGB
• The units are assumed to be meters, while the
  angles are measured in radians.

3
Drawing Shape Node

• Shape node has two fields
• 1) Appearance field specifies an appearance node
  which is used to define color and texture
• 2) Geometry field indicates which shape is to be
  drawn
• Syntax

Shape   appearance NULL  geometry NULL   

4
The value for the geometry field may be any of
the following nodes Box
Cone Cylinder
Sphere Text
5
Appearance Node

• The fields included in this node are
• 1) Material field specifies the color of the
  associated geometry
• 2) Texture field contains ImageTexture,
  MovieTexture and PixelTexture
• 3) TextureTransform specifies how the texture is
  applied to the geometry. 
• Syntax
• Appearance
•  
• material NULL 
• texture NULL 
• textureTransform NULL 
•  

6
Combining Texture w/ Materials

• Image Types
• color The shape's diffuse color specified in the
  Material node is ignored.
• grayscale The image's gray values are multiplied
  by the diffuse color.

7
Light Effects Transformation

• Directional Light
• Point Light
• Spot Light
• Transform

8
VRML Models
VRML V1.0 ascii Separator Texture2
filename "stone.jpg" Cube width 1 height
2 depth 0.15

9
Other VRML models
10
VRML Viewers

• VHSB Viewer
• The VHSB Viewer works with Windows 3.1 and up.
  You cannot explore VHSB spaces saved as .mus
  files without downloading the viewer. Exploring
  VHSB spaces saved as .mus files provide for
  superior functionality over the same space saved
  to VRML format.
• ISB3
• While VHSB was/is totally cool... the future of
  easy 3D graphics on the web truly belongs to ISB,
  Parallel Graphics Internet Space Builder. As
  mention on the Introduction page, to enjoy VRML
  .wrl files (called "worlds"), you need to get a
  VRML plug-in. The plug-in is automatically
  launched when the browser encounters a .wrl
  file. Currently, there are a variety of VRML
  plug-ins available... I strongly recommend that
  you go with Parallel Graphics awesome -free-
  plug-in, known as Cortona. This viewer is great,
  easy and intuitive to use... and unlike many VRML
  viewers... continues to be updated.

11
VRML plug-ins
VRML is generally viewed within a Web browser
like Netscape Navigator or Microsoft Internet
Explorer. These browsers don't support VRML
natively so therefore a plug-in is required to
view VRML content. VRML plug-ins are available
for most platforms, the three most popular being