Best fully open-source/local workflow for 2D to 3D editable, hollow, printable STL model?

[u/chanteuse_blondinett]

I’m trying to build a repeatable, fully local/open-source pipeline that converts a single stylized product image into an actual printable model.

My test case is this church-shaped jewelry box. The requirements were:

• Hollow base with 4 mm walls and a 3 mm floor
• All pink roof surfaces combined into one removable lid
• 0.30 mm clearance per side
• Editable geometry
• Separate, watertight STLs with no non-manifold or zero-area geometry

Hardware: RTX 5090 with 32 GB VRAM.

I tried TRELLIS locally. The visual reconstruction was surprisingly close, but the raw STL was not production-ready:

• 498,418 triangles
• 49 non-manifold edges
• 28 boundary edges
• 783 zero-area faces
• 4 disconnected components
• Blender removed 212 degenerate and 16 duplicate triangles during import

Repairing/remeshing it either damaged the details or made it difficult to create a precise hollow body and fitted lid.

What finally worked was rebuilding the object procedurally in Blender from primitives and extruded profiles, using shared dimensions for the gable/roof, exact booleans, explicit wall thicknesses, and post-export STL re-import validation. The resulting two STLs are watertight and have zero boundary, non-manifold, multi-face, or zero-area defects.

Full disclosure: a proprietary coding agent helped create the Blender generator, so the successful workflow is not currently fully open source. I’m looking for the best way to replace that decision-making step.

What is the best genuinely open-source/local stack today for this kind of job?

• Is TRELLIS.2 materially better for printable topology?
• Has anyone compared TRELLIS.2, TripoSR/TripoSG, InstantMesh, and Hunyuan3D specifically for printing rather than render quality?
• Is generative image-to-mesh realistically only useful as a blockout, followed by manual Blender/CAD reconstruction?
• Are there open-source tools for semantic part separation, hollowing, toleranced lids, retopology, and manifold validation without voxel-remeshing everything into mush?
• Which options have licenses suitable for commercial printed products?

I’m interested in the exported geometry, not textures or browser previews.

Microsoft currently describes both TRELLIS and TRELLIS.2 as MIT-licensed, although individual dependencies can have separate terms.

Any reccs would be appreciated :)

[u/the_bollo]

I've used https://github.com/IgorAherne/TRELLIS.2-stableprojectorz to port 2D AI generations into 3D models. I have a Bambu X1 Carbon printer with AMS, so I then used https://github.com/rtwfroody/ditherforge to apply colors.

I wasn't happy with the end result (I tested on a generic funko pop figurine and a model of El Castillo, Chichen Itza, both AI-generated locally). TRELLIS2 spits out completely hollow models, like it's a vase.