Collada Importer
This is the WIP page to document the design and implemenation of a Collada to POF model converter. This article was created in response to Cash prize for Collada - POF support!
Contents
Background
The goal of this project is to create a stable import system with which to convert the open-standard Collada (DAE) XML-based model format to the Freespace POF binary model format. Many other export options exist, but each has its flaws and none seem to work flawlessly. Using a cross-application format such as Collada and a community-developed converter should help address many of the existing issues. The conversion application PCS2 already has COB->PMF, PMF->POF, and the reverse of both. We have access to the specifications for POF through Volition's documentation but the format is difficult to work with directly. We have access to the PMF specification through the source code to PCS2, but better documentation (in a more human-readable format) for this could be useful. However, PMF is designed to be an easily-accessed format to be used in between other formats and the PMF->POF conversion routines in PCS2. Currently the plan is (barring serious objection by the community) to create a library of routines to convert a DAE file to a PMF file. This library could then be utilized in PCS2 using its existing PMF->POF support, or that functionality could be utilized in another standalone converter. With that in mind, the following are the requirements and specifications a converter and the models must adhere to. As for working with the Collada format, one such possibility is the FCollada library, a free set of routines to interface with Collada.
DAE File Prerequisites
The conventions for a DAE file will be similar to those for Styxx's POF Conversion plugin for 3D Studio Max. All major modelings apps should be able to understand a model that follows these conventions.
Treat everything as case sensitive. All numerical sequences to be interpreted by the converter must be contiguous and begin with 01 unless otherwise specified.
For appropriate helper generated fields the centre is determined by translation field, the radius is determined by the X scaling and the normal is determined by the rotation fields.
This list is in progress and is subject to change. Suggestions should be made in Cash prize for Collada - POF support!
LODs
detailX, where X ranges up from 0 at top level.
Subobjects
Subobjects should be set as children of their desired parent object. Turret barrels should be a child of their turret base. Helpers should be grouped as children of a child of the subobject with a name starting with "helper".
Debris
debrisXX at top level.
Shield
shield
The shield mesh should be triangulated and at top level.
Subsystems
subsystem<subsystem name>, no <>, at top level. Helpers should be grouped as children of a child of the subsystem with a name starting with "helper".
Engine Glows
Grouped as children of a node with a name starting with "thrusters". Should be a child of a helper node if linked to a subsystem or at top level otherwise.
Dockpoints
Grouped as children of a node named "dockpointXX" at top level. Helpers should be grouped as children of a child of the dockpoint with a name starting with "helper".
Gun banks
Grouped as children of a node named "gunbankXX" at top level.
Missile banks
Grouped as children of a node named "missilebankXX" at top level.
Turret Firepoints
Grouped as children of a node with name starting with "firepoints" which is a child of the turret submodel node helper node.
Eyepoints
eyepointXX at top level.
Paths
Grouped as children of a node with name starting with "firepoints" which is a child of the subsystem, submodel or dockpoint helper node.
Converter Requirements
Must output a PMF compliant with the structure utilized by the PMF importer of PCS2.
External Links
Cash prize for Collada - POF support!
PCS2 CVS Repository - For COB->PMF reference, only PMF format docs
Styxx's POF Conversion plugin for 3D Studio Max - The basis for the DAE model conventions
