Jwir3's Weblog

Before beginning work on the ConvertGeometry() design, I have begun reading the COLLADA: Sailing the gulf of 3D digital content creation book, in order to better acquaint myself with the esoteric aspects of COLLADA. I have found that the book is quite political, with a large amount of unnecessary historical background and self-justification on the part of the authors. While this is a harsh criticism, I do find that the information in the book is extensive and extraordinarily relevant to the project at hand.

In reading the book, and gaining insight of the COLLADA format from the authors' perspectives, I have come across an interesting design question: Is it necessary to include the <asset> tag in the conversion process from COLLADA to CS? The asset tag seems designed to give credit to the author of the 3D media and to represent what type of software/hardware configuration the media was designed on, as well as for. The dilemma occurs when we consider that there is no symmetric place for this information in the Crystal Space map/library files.

I submit that this information is not necessary to include in the Crystal Space map/library file for two reasons:

1. Crystal Space digital media files, while an open standard, are proprietary to the Crystal Space project. I mean this in that, the files are not restrictive of licenses and/or copyrights, but that the files are specific to the Crystal Space engine. An artist would not use a Crystal Space map file for a map designed to run on the Unreal engine. Because of this, COLLADA files are likely to be the file of choice for artists and media contributors to store/backup/retain their files in, assuming they will be converting from COLLADA to Crystal Space. This last bit is important - if someone intends to use the COLLADA conversion system, it is likely (not guaranteed) that they will want to use COLLADA as their storage format, and Crystal Space as their runtime format.


2. Information about which tool was used to produce the media is unneccessary, provided it works inside the Crystal Space engine. Does it matter whether Maya or Blender was used to produce a model, if it looks the same in Crystal Space? I argue no.

Given these two reasons, I will proceed with the intention that the asset tags can be completely removed, and not converted to Crystal Space format. If this is not an acceptable conclusion, I believe the Crystal Space file format would need to be changed. However, I think changing the file format to include this information would be unnecessary and, in fact, wasteful of time and space complexity. After all, the more tags that the engine needs to parse during rendering, the longer it will take per frame, and information about the author isn't going to affect how the frame looks in the end, right?

I will be working tomorrow on design schematics for the ConvertGeometry() operation, and hope to have final versions ready for the design log tomorrow.