I hereby declare myself a Colada newbie, and beseech the kindness and patience of Collada gurus who may be listening in the ether for wisdom and guidance. I seek clarity of semantic terms, and better understanding of “the grand design.”
After reading scripture (the 1.4 spec), and examining the “LondonHouse.dae” sample provided by Google at: http://earth.google.com/kml/kml_21tutorial.html#models , I am confused. I see that oriented, sampled reality (i.e. a picture) can be described as a diffuse “effect”, and that merely defining lines requires a sematic definition (<input semantic = “VERTEX” … )
Dare I ask where rich knowledge from parallel universes might join the Collada universe! Dare I utter the phrase! (R…RDF!!)
definitions of holy keywords, RTFMs, and deeds of penance welcomed.
Apologies for an additional note: this beseechment is in response to having looked at the .xsd in XMLSpy for a long while, and having compiled it into a wad of Java Objects.
Perhaps this is a good moment to mention the forthcoming COLLADA book?
Regarding geometry, COLLADA uses a stream programming model to describe the assembly of mesh primitives in a relatively compact XML representation. A mesh is comprised of primitive collation elements (eg <triangles>) that assemble the vertex attributes (POSITION, NORMAL, COLOR, TEXCOORD, etc.) from the input streams into the named primitive. The inputs refer to data sources that are most often represented by arrays of homogenous data, however the source data can be externalized. The data sources do not have semantics enabling data compaction and reuse. The semantics are defined by the inputs.
I hope that helps!
An excellent time to mention the book!
> however the source data can be externalized
I will definitely play with this aspect; no doubt it will often be preferable to just refer to “standard” textures and geometry streams that are URL-accessible, rather than having to zip/ship them every time…but of course the double-edge sword of reuse versus external dependencies can cut both ways.
thank you for these words of buidance.