johnnyquest / habcgeomexport Goto Github PK

This would be especially useful for fractured rigid body simulations. The Houdini way by default is to store all in a single deforming object.

The pros for exporting as multiple objects is each would have its own xform matrix which allows for better rotational motion blurs as well as probably less data to export/store.

Or alternatively, a quick batch file for windows users. :)

Do this. Make sure they can be read back into Maya somehow (Szabolcs suggested vertex colors as a workaround).

Per-point, per-vertex, per-primitive, detail types.

Export frame steps less than 1.0 doesn't seem to work (not tried it anything else but 1.0, actually).

(...by conjuring up a nice hackety-hack batch file, for now.)

The code is laced with lots of debug output to always see what's going on (even when not debugging). Get rid of these once things seem stable enough.

Currently all transformations are exported as matrices (pretransform and local transform multiplied and that's it.) They should be written in a more detailed way, using hints-and-stuff, and most especially, something for rotations that allows the original values to be reproduced (to avoid euler flips).

• houdini->maya translation with 'facevarying' normals/uvs sometimes work, sometimes don't (?) (is it the exporter or the importer? am I exporting these correctly?);
  • I'm not sure how the Maya importer tolerates per-point normals and uvs (meaning non-facevarying types);
  • the code uses the 'varying' type for normals/uvs that are per-point, is that the correct type?
  • I'm exporting facevarying uvs the same way as facevarying normals (ie. I don't export an indices array for them, just writing the data for each vertex and that's it). Is that correct?

Needs lots of testing to end up bullet-proof.

Only geometric objects should be written as polymeshes (currently null objects, etc. are written as empty polymeshes, too).

In order to properly build it for Houdini, all alembic and -related includes and link libraries should be provided by SideFX with the Houdini install. (Especially on windows)

getting the following error when trying to build:

ld: duplicate symbol bool GVEXimportData<UT_Matrix4T >(GB_GenericData const&, UT_Matrix4T&)in src/hAbcGeomExport.o and src/GeoObject.o for architecture x86_64
collect2: ld returned 1 exit status
make: *** [/Users/mofo/Library/Preferences/houdini/11.1/dso/hAbcExport.dylib] Error 1

This error has been confirmed by myself and also another user in the alembic googlecode group.