what's in the cage?

had a little problem trying a new technique that seemed solid beforehand. i needed some asteroids for the project so, thinking it would be a fairly simple model, i thought to try a little change-up in my workflow in attempt to expedite the process.

what seemed like it should be no problem, turned out to be a little bit of a headache in the long run. basically, my idea was to produce a set of six asteroids at once, as opposed to creating them all one at a time.

thus, i set out for the journey in zbrush, opting to cut out the initial base mesh modeling phase of my workflow. i laid out zbrush cube primitives into a row and proceeded to merge them into a single subtool with individual polygroups to dynamesh and begin the sculpt.

sculpting went fine. i tried out some new brushes i was unfamiliar with and settled pretty quickly on six very basic asteroid forms. then, i exported the highest level subdivision for baking, as well as a decimated version for reference when making the cage in maya. to create the low poly, i used zremesher once in adaptive mode and then a few times in half mode until the silhouette looked as low as it could go.

transitioning into maya with the low poly and the decimated high, i separate the low poly meshes and layout the uvs. to create the cage i duplicate the low poly and move the verts out along the normals axis. this is the stage where i created a headache for myself.

the problem did not show itself until i began to bring the models into the new software ive recently integrated into my workflow, substance painter. because substance provides a unique texture set for each separate mesh, i also applied matetials to each mesh to separate them into texture sets for painter, while i was in maya.

essentially, the problem arose from trying to project all of the texture sets (or each asteroids textures) using a single combined cage. although the cage and low poly were identical, the problem laid in the fact that the cage was constructed from the combined set of asteroids, thus it contained overlapping uvs. no other projection method ive used in the past cared if the mesh had any uvs at all, let alone if they were overlapping. this took me longer than i would like to admit to figure out, due to the fact that i am only beginning to learn substance painter. the implentation of texture sets is nice, i just needed to wrap my head around the software a bit better.

eventually, it hit me. i surmised that somehow the cage must be the issue because baking without a cage did not produce any errors. while toying around with different ways to export, i even tried moving the separate meshes uvs into different quadrants of the grid so they wouldn’t be overlapping, but instill hadn’t quite hit the mark.

the key was to bake all the low poly meshes with their own specific cage, for each texture set, one by one. in retrospect, it makes perfect sense and i love that. far too often am i plagued with technical issues which stem from corrupt files or software bugs/incompatibility. it is refreshing to once in awhile find a sollution to a computer issue and achieve that metaphorical lightbulb going off inside your mind.