more of a workaround, at least stops crash.

- UV information is now preserved when adding new faces
(interpolating UV coordinates). This can be switched off
in the user preferences.
- Quad strips can now be finished with a single triangle.

Now I'm sure of it - most app apart from latest AD ones do not yet support new normals
format (102, 4D vectors + weights), so revert to older 101 one (3D vectors).

Checked on both houdini and unity.

Since there is now a node for this :)

Bad news is: we have to hack at binary level! Yes, some kind of elements do have
some specific need binary-wise. I won't say what I think of this.

E.g. camera, lamp and empty (Null) data all use the same "NodeAttribute" element type,
while having different "sub-types" (FbxNull, FbxCamera, etc.) with different properties.

It would have been perfectly possible to have multiple property templates, but from
"reading" official FBX files, it’s obvious this is not supported, so in this case we
have to pick one to write a real template, and for the other subtypes, we have to
explicitely write the whole templates' content in each and every element...

At this point, you might wonder why introducing templates, if you have to handle
such hairy cases? Well, I’m wondering too...

FBX: Fix stupid bug with mats/textures (from recent usage of OrderedDict), reported by a user on blog, thanks!

FBX: more minor tweaks (main here is making uids shorters, easier to read in JSONed version of files).

patch T36787 by Andrew Peel with own modifications.

It is now possible to merge nodes using Z-Combine nodes. Keyboard
shortcut: Ctrl - NUMPAD (dot).

FBX: Use more OrderedDict (to keep things cleaner in FBX file), and try to make output even more compatible with genuine FBX files (anim aspect), still no luck. :(

Patch by Zer0 (vince), many thanks! :)

Another Great Breackthrough in FBX Ugliness: properties seem to have complete different signature when they are animatable or not!

E.g.: for double properties, non-animatable will be ("double", "Number", ""), while animatable ones will be ("Number", "", "A"). Yep, looks like a good old flag is not enough...

Btw, this still does not fix animation issue (since Lcl Translation & co are not affected by this, they seem to always be animatable...).

Note this code is highly theorical, I could not get to test it really (other apps I have access to also fail at importing FBX anim generated from collada by FBXConverter :( ).

For now, only basic (loc/rot/scale) of objects is implemented. Will wait for other testers' feedback before going any further.

FBX: since we have more and more options differing between new 7.4 and legacy 6.1, add a draw() func (temp, to be removed once we get rid of 6.1).

Finally understood a bit better Property format (name, type, kind_of_label?, flags, data, ...).
So needed to handle flags properly (currently, only aware of 'A'nimatable and 'U'ser-defined (aka custom),
no idea yet what means the '+' one found in some places).

Also changed templates definitions to use OrderedDict's, gives better output.

Since global matrix might have some scale too, we have to normalize the matrix used for normals...

Many thanks to Jens Restemeier for pointing this issue.

This addresses the following issue: by default, when you export in a non-Blender orientation
(matching your target import app), your imported root objects have additional rotation,
since correction matrix is applied to object transform.

This patch addresses this by actually baking the correction matrix at data level, when possible
(currently only works for meshes).

Note this makes spaces/matrices handling rather complex, so this is considered an experimental
option currently, might break in some cases.

Work based on patch T39251 by Jens Restemeier, thanks.

Many thanks to Daniel Martinez-Normand for reporting the issue and making tests! :)

* Use 100% white transparency color when no transparency at all (seems to be needed by some importers).
* Always export some kind of Lambert shader, even when using e.g. Blender's toon one (better to get something, even inacurate, than nothing).

Patch by Jens Restemeier, many thanks!

Differential Revision: https://developer.blender.org/D405

Patch by Jens Restemeier, many thanks! :)

Differential Revision: https://developer.blender.org/D402

Patch by Jens Restemeier, with minor edits.

Differential Revision: https://developer.blender.org/D401

Updates:
* Better positions for new Mix nodes
* Replace Swap Outputs with a generic Swap Links function: It works the same if two nodes are selected. If one node with one input linked is selected, the link is cycled through the available inputs. If one node with two inputs linked is selected, the two links are swapped (useful if you want to swap the inputs of a Mix node for example)
* Lazy functions now work on nodes that are in frames

New features:
* Add Image Sequence - just a speedy way to select just one image from a sequence in the file browser and have it automatically detect the length of the sequence and set the node appropriately
* Add Multiple Images - simply allows you to select more than one image and adds a node for each (useful for importing multiple render passes or renders for image stacking)

Issue pointed out by Jens Restemeier, thanks!

What to expect:
* Static export of empties, meshes, cameras and lamps, as well as materials and (image!) textures should work OK.
  There are a few advanced topics still TODO regarding meshes and mat/tex, though.
* Custom properties from objects/meshes/lamps/cameras/armatures/bones/materials/textures are exported too (only simple ones, ints/floats/strings).
* Armature export: this needs testing by people having *native* FBX aplications, linking between bones and meshes seems to work, but I have doubts about bones orientations.
* Animation: still a complete TODO.

Note that old FBX ASCII 6.1 exporter is still available (top dropdown in exporter's UI).

Many thanks to Campbell, which did the ground work of decyphering FBX binary format and wrote basic code to read/write it.