.WRL File Format

Introduction

VRML 1.0 was announced in 1995 as the first version of the Virtual Reality Modeling Language. The language was taken from the ASCII file format of SGI’s Open Inventor toolkit, with web links added (WWWAnchor and WWWInline). A VRML 1.0 world is a static scene: there are no sensors, events, sound or scripts. Those came with VRML97, which is not compatible with it.

Files are named .wrl like VRML97 files and are told apart by the header line.

Structure

The first line is #VRML V1.0 ascii. The rest is a list of nodes. Unlike VRML97 the nodes are not nested by what they own but run in order: a group node holds a list of children written straight inside its braces, and a scene is drawn by walking that list while keeping a state: the current transform, material, coordinates, texture and so on. Nodes such as Material, Coordinate3, Translation and Rotation change the state; shapes such as IndexedFaceSet, Cube and Sphere are drawn with the state as it is. A Separator saves the state when it starts and restores it at its end, so its changes stay inside it.

#VRML V1.0 ascii
Separator {
  Material { diffuseColor 0.9 0.6 0.3 }
  Separator {
    Translation { translation 0 1 0 }
    Sphere { radius 0.5 }
  }
  Coordinate3 { point [ 0 0 0, 1 0 0, 0 1 0 ] }
  IndexedFaceSet { coordIndex [ 0, 1, 2, -1 ] }
}

Values are written as in VRML97 (numbers separated by spaces or commas, strings in double quotes, lists in square brackets) with two differences: enumerated values are bare words (value PER_FACE) and a bit mask is a set of words in parentheses (parts (SIDES | BOTTOM)). Names given with DEF can be used again with USE.

In this reference

• Syntax and traversal – the header, comments, field types, DEF and USE, the state and the bindings
• Nodes – all 36 nodes with every field, type and default

Opening VRML worlds in the explorer

Drop a .wrl file on this site’s explorer. It reads VRML 1.0, VRML97 and the X3D classic encoding, shows the nodes as a tree with each field described and checked against the node’s definition, lists the problems it finds, and draws the shapes (boxes, spheres, cones, cylinders, face and line sets, elevation grids and extrusions) with their material colours. Textures, lighting, transparency, text and animation are not drawn, and files named by the world (textures, inlined worlds) cannot be read because a dropped file comes without its folder.

Not described

What this reference and the explorer leave out.

• Reference: written from memory of the VRML 1.0 specification and not checked against it. Extension nodes declared with a fields list, and the exact rules for part and vertex bindings, are not described.
• Viewer: draws the shapes with diffuse colours (overall, per face and per vertex). Normals, ambient, specular and emissive colours, transparency, textures, text, cameras and lights are not drawn, and WWWInline files are not read. Only three real VRML 1.0 files were available, none using bit masks or per-vertex binding.

Variants

• VRML 1.0 – the 1995 version, based on Open Inventor: a state machine of properties and shapes inside Separator nodes
• VRML97 – VRML 2.0, ISO/IEC 14772: a scene graph with PROTO, ROUTE, sensors and scripts
• X3D classic encoding – the same text syntax as VRML97, with PROFILE, COMPONENT and META statements (.x3dv)

Links