For patch/wave instancing, an additional step is required prior to export. This neccessity comes from the fact that a couple of crucial attributes ("planeorig" and "rolloff"), and the particle system holding the actual instance points, are lost when converting the spectra to VDBs. To resolve this, one needs to use a "Split" SOP to isolate the points by e.g. "@name=pointmask" and use a "Convert VDB Points" SOP to pack them into a VDB volume. Then, the "planeorig" and "rolloff" attributes are added back onto the newly created "pointmask" VDB. Finally, the "pointmask" VDB is merged back to the spectra VDBs, and everything is exported to disk. |