I'm a long time user of Qubicle Constructor V1.6 (yes, it's taken me that long to upgrade!) and I've just installed V3 (Indy Version).
My export settings on the old V1.6 for OBJ were as follows:
Export as: One object per matrix
Settings for multimaterial: Hexadecimal
The new V3 export settings are a little confusing to me, and now when I export a model, even though I have multiple colours, it appears to export it as a single object, so when I import it into my 3d program, I can't edit any of the parts/colours.
Please could someone advise me the export settings required in V3 to export the same way that I do in V1.6?