I3D Format

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Table of Contents

  1. Introduction
  2. Features
  3. Overview
  4. Specification
    1. General Layout
    2. Materials
    3. Shapes
    4. Dynamics
    5. Scenegraph
    6. Animation


I3D is an eXtensible Markup Language (XML) file format.

A vaild I3D file has up to seven parts: Textures, Materials, Shapes, Dynamics, Scene graph, Animation and Userdata. Dependent on application each part can be omitted.

The XML Schema language is used to describe the I3D feature set. Download: I3D 1.6 Schema


  • Scenegraph hierarchy with
    • TransformGroups/Bones: translation, rotation, scale and visibility
    • Lights: ambient, point, directional and spot lights
    • Cameras: field of view, near and far clipping plane
    • Shapes: meshes and nurbs curves (supports geometry instancing)
    • Particle Systems
  • Animation
    • Animation sets
    • Clips
    • Keyframes: translation, rotation, scale and visibility
    • Morph Targets
  • User Attributes
  • Dynamics
    • Particle Systems (Sprite based)
      • Surface Emitter
      • Gravity Fields
      • Air Fields
  • Meshes
    • Vertices
    • Normals
    • Vertex colors
    • Skin weights
    • Texture coordinates (including multiple uv sets)
    • Faces (vertex color, normals and texture coordinates per face)
  • Curves
    • Nurbscurves
  • Shader/Materials
    • Multitextures (arbitrary layered textures)
    • Lightmaps
    • Bumpmaps/Normalmaps
    • Environmentmaps
    • Specularmaps




General Layout

  <?xml version="1.0" encoding="iso-8859-1"?>
  <i3D name="MyScene" version="1.6" xsi:noNamespaceSchemaLocation="http://i3d.giants.ch/schema/i3d-1.6.xsd">

Coordinate Systems

I3D uses a right-handed coordinate system.


All used file references are defined here. File handles are mapped to the corresponding filenames.

    <File fileId="1" filename="myTexture1.png" relativePath="true"/>


Materials used in the materials attribute of Shape nodes within the scenegraph section are defined in this section.

    <Material name="myShader_001" materialId="12">
      <Texture fileId="1"/>


Shapes are defined here and referenced from the scene graph section. This mechanism allows multiple instancing of shapes.


Dynamic objects are defined in this part and referenced from the Scene graph section.

    <ParticleSystem name="emitter1" dynamicId="1" type="sprite" rate="0.004" lifespanInfinite="false"
    speed="0.01" speedRandom="0" tangentSpeed="0" normalSpeed="1" lifespan="10000" maxCount="1000"
    spriteScaleX="50" spriteScaleY="50" depthSort="false" emitterShape="pCubeShape1" shader="lambert2">
      <Gravity force="0 -3 0"/>
      <Air velocity="2 0 0"/>


The Scene graph hierarchy (transformations, bones, joints, shapes, lights, cameras and particle systems) are stored in this section. Shapes, materials and particle systems are stored as references.

    <TransformGroup name="myGroup1" translation="1.25 0 -9" nodeId="47">
      <Shape name="mySphere" materialIds="1" shapeId="1" nodeId="48"/>
      <TransformGroup name="myGroup2" rotation="90 0 270" nodeId="49">
        <Shape name="mySphere2" materialIds="1" shapeId="2" nodeId="50"/>

Scene graph node types


Attribute Description Type Optional
name Name of TransformGroup string no
translation Translation complex yes
rotation Rotation, euler order ZY'X'' complex yes
scale Scale complex yes
visibility Visibility boolean yes
kinematic Kinematic object boolean yes
dynamic Dynamic object boolean yes
static Static object boolean yes
compound Compound parent boolean yes
compoundChild Compound child boolean yes
collision Enable collision boolean yes
ccd Continuous collision detection boolean yes
trigger Trigger boolean yes
cloth Cloth boolean yes
restitution Restitution float yes
staticFriction Static friction float yes
dynamicFriction Dynamic friction float yes
skinWidth Skin width float yes
density Density float yes
collisionMask Collision mask integer yes
joint Joint boolean yes
breakableJoint Breakable joint boolean yes
jointBreakForce Joint break force double yes
jointBreakTorque Joint break torque double yes
projection Enable joint projection boolean yes
xAxisDrive Enable x axis drive boolean yes
yAxisDrive Enable y axis drive boolean yes
zAxisDrive Enable z axis drive boolean yes
drivePos Enable drive position boolean yes
projDistance Projection distance double yes
driveForceLimit Drive force limit double yes
driveSpring Drive spring double yes
driveSpring Drive spring double yes
solverIterationCount Solver iteration count integer yes
rotMinX Rotation minimum x double yes
rotMinY Rotation minimum y double yes
rotMinZ Rotation minimum z double yes
rotMaxX Rotation maximum x double yes
rotMaxY Rotation maximum y double yes
rotMaxZ Rotation maximum z double yes
transMinX Translation minimum x double yes
transMinY Translation minimum y double yes
transMinZ Translation minimum z double yes
transMaxX Translation maximum x double yes
transMaxY Translation maximum y double yes
transMaxZ Translation maximum z double yes
objectMask Object mask integer yes
nodeId Node reference id, used for Animation and UserAttributes section integer no

Element Description Type Cardinality
TransformGroup Transform group node complex 0..N
Shape Shape node complex 0..N
Camera Camera node complex 0..N
Light Light node complex 0..N
Dynamic Dynamic node (eg. particle system) complex 0..N


Attribute Description Type Optional
shapeId Shape reference id (reference to shapes section) string no
materialIds List of used material ids (reference to materials section) string no
skinBindNodeIds Skin bind node ids string yes
castsShadows Casts shadows boolean yes
receiveShadows Receive shadows boolean yes
clipDistance Clip distance double yes
nonRenderable Non renderable boolean yes


Attribute Description Type Optional
fov Field of view double no
nearClip Near clipping plane double no
farClip Far clipping plane double no


Attribute Description Type Optional
type Light type string no
diffuseColor Diffuse color complex yes
emitDiffuse Emit diffuse string yes
specularColor Specular color complex yes
emitSpecular Emit specular string yes
castShadowMap Cast shadow Map boolean yes
depthMapBias Depth map bias double yes
depthMapResolution Depth map resolution integer yes
shadowFarDistance Shadow far fistance double yes
shadowTextureOffset Shadow texture offset double yes
shadowExtrusionDistance Shadow extrusion distance double yes
decayRate Decay rate integer yes
coneAngle coneAngle double yes
dropOff dropOff integer yes
projTexture Projective texture name string yes
range Range double no

5 Dynamic

Attribute Description Type Optional
dynamicId Dynamic id (reference to dynamics section) string no


  <Camera name="camera1" translation="0 2.00 6.47" rotation="-13.07 0 0" fov="54.43" nearClip="0.01" farClip="1000" nodeId="34"/>
  <Light name="pointLight1" translation="6.56 5.76 4.04" type="point" diffuseColor="1 1 1" range="10" nodeId="35"/>
  <TransformGroup name="group1" translation="1.35 0.96 0.81" nodeId="36">
      <Shape name="pCubeShape1" rotation="-23.94 6.49 14.29" materialIds="1 2" shapeId="1" nodeId="37"/>


Motions are defined in this part. Clips are the basic building block and allow Non-Linear Animation by composing multiple clips.

      <AnimationSet name="walk_crouched">
        <Clip name="walk_crouched1Source" duration="1000">
          <Keyframes nodeId="Hips">
            <Keyframe time="0" translation="-0.467 13.504 39.842"/>
            <Keyframe time="333" translation="-0.559 12.915 39.370"/>
            <Keyframe time="1000" translation="-2.610 11.917 35.462"/>
          <Keyframes node="Chest">
            <Keyframe time="0" rotation="-1.013 -4.465 0.890"/>
            <Keyframe time="666" rotation="10.009 -6.667 4.381"/>
            <Keyframe time="1000" rotation="11.638 -3.906 4.115"/>