This is a recreation of the PR @robertlong submitted long ago here:
https://github.com/facebookincubator/FBX2glTF/pull/97
Refactors and whitespace conflicts made this easier.
There is still a substantial rewrite of the texture-loading and
file-path handling pending, for sometime soon.
Hopefully without unintentional changes to functionality. This renames header
files to .hpp, imposes a gltf/raw/fbx directory structure, extracts standalone
chunks of Fbx2Raw into distinct files, and undoes some particularly egregious
mistakes from when I knew even less C++ than I do now.
This is in anticipation of implementing 3ds Max's "Physical Material".
The FBX SDK looks for our textures and often finds them. It helpfully
tells us exactly where they are. Let's not throw that information away
and demand that the textures only exist in precisely the folders we are
aware of.
When we convert a file that's in our CWD, on Unix the folder component
of the path will simply be "", whereas opendir() wants ".".
I want to take another more substantial pass at texture resolution, once
we're out of urgent bugfix mode.
When we've successfully located a referenced texture image on the local
filesystem and we're generating non-binary, non-embedded output, copy
the source folder wholesale into the destination directory.
This means the output folder is always a full, free-standing deployment,
one that can be dragged into e.g. https://gltf-viewer.donmccurdy.com/
* Further improvemens to texture resolution.
- Move towards std::string over char * and FbxString where convenient,
- Make a clear distinction between textures whose image files have been
located and those who haven't; warn early in the latter case.
- Extend RawTexture so we always know logical name in FBX, original file
name in FBX, and inferred location in local filesystem.
- In non-binary mode, simply output the inferred local file basename as
the URI; this will be the correct relative path as long as the texture
files are located next to the .gltf and .bin files.
Primary remaining urge for a follow-up PR:
- We should be copying texture image files into the .gltf output folder,
but before that we should switch to an off-the-shelf cross-platform
file manipulation library like https://github.com/cginternals/cppfs.
When we make that transition, all this texture resolution code will
undergo another refactoring.