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- Feb 1 2017, 11:05 AM (194 w, 6 d)
May 25 2020
Apr 10 2018
I've confirmed these observations with Maya, Houdini, UE4. One clue that might be useful--Unity's open-source Alembic importer _does_ accept Blender Alembic files with vertex colors (as long as you use their hard-coded attribute name "rgba").
Oh cool, sounds like folks are on the trail of a solution!
Feb 20 2018
Here's what I've got so far...it builds successfully and exports valid Alembic files, but abcls doesn't find the mayaColorSet=1 flag so I'm still doing something wrong.
Alembic::AbcCoreAbstract::MetaData md; md.set("mayaColorSet", "1"); OC4fGeomParam param(prop, name, true, kFacevaryingScope, 1, 0, md);
Feb 19 2018
OK, progress--I can build Blender from source with Alembic enabled. Next step, @Dario Seyb (daseyb) says for Unity he used the following to add the Maya color set flag:
AbcGeom::MetaData md; m.set("mayaColorSet", "true"); m_colorSet = AbcGeom::OC4fGeomParam(m_scheme.getArbGeomParams(), “Cd”, true, AbcGeom::GeometryScope::kFacevaryingScope, 1, m_tsi, md);
Could you help me adapt this for Blender in abc_customdata.cc? I'm getting more certain that this is the fix to make Blender vertex colors readable in Houdini and Maya.
Feb 17 2018
If I wanted to recompile Blender's Alembic export module with the mayaColorSet=1 flag added, where in the source should I look?
Jan 15 2018
Here's how vertex colours are represented in each of the Alembic exports. Can anyone tell me why Houdini and Maya can see each other's vertex colours, but Blender's aren't visible in Houdini or Maya? Looking at the logs here, is it just as simple as adding a mayaColorSet=1 flag to the Blender compound property on export?
Dec 12 2017
No worries, reposted with new tests at https://developer.blender.org/T52417#474982
To make the attached test, I took the same mesh into Blender, Maya, and Houdini, and exported an Alembic file with vertex colours from each; the attributes are all named Cd to match Houdini convention. (In Blender I applied vertex colours with the common Python function below, just in case that's helpful to know.) The results:
Dec 11 2017
This might be a related issue--currently I can't access Alembic vertex colors exported from Blender 2.79 in Houdini or Maya. In Blender Python, I've created a vertex color layer named Cd; the color set is visible in Maya when imported with -rcs flag, but contains no data; in Houdini the Cd attribute isn't visible at all. However, the Cd attribute still exists in the Blender alembic file and is visible on re-import.