aw-sequence-parser

Javascript parser for Active Worlds (AW) sequence files

Usage

The parseSequence function expects two parameters:

• uri: mandatory, pointing to the resource (the url of some AW .zip sequence file for example)
• 'opts': optional, set of options to provide to the parser.

If nothing is provided, opts will hold the following values:

{
  fileType: FileType.AUTO, // Auto detect file type (WIP)
  fflate: null,            // fflate module, mandatory to extract zipped sequences
  cors: false              // Set to 'true' to enable CORS policy on http(s) request
}

In practice: it's highly recommended to provide such opts dictionary with fflate set, as zipped binary sequence files are usually the default way to go for AW object paths.

parseSequence will return the Promise of a dictionary for the freshly-parsed sequence file:

{
  "fileType": "binary",             // The type of file this was extracted from, binary files are meant to be 30fps animations
  "totalNFrames": 413,              // Total number of frames for this animation
  "nJoints": 27,                    // Number of joints involved in this animation
  "modelName": "lmarsha",           // Name of the 3D model the sequence was meant to apply to, as an hint
  "rootJointName": "pelvis",        // Name of the root joint to apply translations to
  "frames": {                       // Key frames held in a dictionary (indices starting from 1)
    "1": {
      "joints": {
        "pelvis": [qX, qY, qZ, qW], // Quaternion parameters for each joint in the frame
        "back":  [qX, qY, qZ, qW],
        ...
      },
      "location": [x, y, z]         // Translation to apply to the root joint for this frame
    },
    "3": {
      "joints": {
        "pelvis": [qX, qY, qZ, qW],
        "back":  [qX, qY, qZ, qW],
        ...
      },
      "location": [x, y, z]
    },
    ...
  }
}

Note that the number of provided key-frames will often differ from totalNFrames: those missing frames are meant to be interpolated later on by the actual client making use of this parser.

Getting RWX joint tags

Joint tag numbers, as specified in RWX clumps from avatar models, can be fetched from joint names by importing and using getJointTag(jointName); (where jointName can be something like 'pelvis', 'back', etc...), it is meant to be case-insensitive.

If the joint name is invalid: it will return undefined.

Example

import parseSequence, {FileType, getJointTag} from 'aw-sequence-parser';
import * as fflate from 'fflate';

walkSeqPath = 'http://objects.activeworlds.com/uberpath/seqs/walk.zip';

const seqPromise = parseSequence(walkSeqPath, { fileType: FileType.AUTO,
                                                fflate,
                                                core: true });

seqPromise.then( seq => { /* Handle sequence here */ });

const pelvisTag = getJointTag('pelvis'); // 1
const lfkneeTag = getJointTag('LFKNEE'); // 20
const invalidTag = getJointTag('I do not exist'); // undefined

Testing

$ npm test

Linting

$ npm run lint

References

• http://www.imatowns.com/xelagot/seqspecs.html