Collada Importer

This is the WIP page to document the design and implementation of a Collada to POF model converter. This article was created in response to Cash prize for Collada - POF support!

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. 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.

Glowpoints

Grouped as children of a node with name beginning with "glowbank" which is a child of the submodel of the glowbank. Texture name should be stored as a property "$glow_texture=<texture name>". Timing, type, normals and LOD are ignored pending suggestions on dae format storage

Insignia

insigLODXX-YY; triangulated UV-mapped mesh at top level; texture will be included in the texture list unless its name begins with "insignia".

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!

COLLADA Specification

FCollada Home Page

PCS2 CVS Repository - For COB->PMF reference, only PMF format docs

COLLADA Test Model Bank

Spicious' PCS2 Dev Build with Collada support Libcollada DLL for this build VC2008 Runtime for this build

POF Constructor Suite 2

Styxx's POF Conversion plugin for 3D Studio Max - The basis for the DAE model conventions