* Split and rewrite the preview window and canvas.
* Create a new class for handling the board information.
* Adds new render targets: openGL, legacy, and ray tracing.
* Render targets take full advantage of the new 3D plugins system and 3D cache
for a fast 3D model loading.
* Faster board loading.
* New OpenGL render is faster than the old one.
* New ray tracing render target with a post processing shader.
* Use of new 3D plugins (WRL, X3D, STEP and IGES) and 3D model caching.
* Preview of 3D model while browsing the file name.
* 3D preview of the footprint while adding / align 3D shapes.
* Render of 3D models according to attributes: Normal, Normal+Insert, Virtual.
* Pivot rotation centered in one point over the PCB board.
* Shortcuts keys improved for XYZ orientation..
* Animated camera.
* Paths defined via pcbnew->Preferences->Configure Paths are now included in
the 3D file browser's drop-down list except for KICAD_PTEMPLATES, KIGITHUB,
KISYSMOD, any paths resembling a URL, and any non-existent paths. When an
absolute path is shortened using one of these path aliases, let's say
'KISYS3DMOD' then the name appears in the pcb file as "${KISYS3DMOD}/blah.wrl".
If a user defines and actual environment variable with the same name, then
that user defined variable will have precedence over the internally defined
variable.
* Paths relative to the current project directory are no longer represented
as "some/path/to/file.wrl". For compatibility with previous KiCad versions
it shall always be stored as ${KIPRJMOD}/some/path/to/file.wrl.
* Various restrictions on alias path values have been removed since the
imposed restrictions could result in corrupted user data as aliases are
silently dropped.
* Overall the patch should improve back-compatibility by providing a ${ENV_VAR}
mechanism for supporting different model root directories and ensuring that
paths relative to KIPRJMOD are expressed in a way that is compatible with
earlier KiCad versions. This allows users more flexibility and the ability
to work in a way that ensures 3D model files can be correctly resolved in
earlier versions of KiCad. Users who do not care about back-compatibility
may prefer to use the newer alias system.