How to Make Custom D&D Minis With AI (Text or Photo to Printable STL)

To make a custom D&D mini with AI: describe your character as a single standing figure (race, class, pose, gear, weapon) or feed the tool one clean reference photo, generate the model, export a watertight STL, scale it to 28-32mm in your slicer, then add supports and print — resin for fine detail. The AI builds the mesh; you handle supports and slicing. This guide covers the prompt tricks that keep a mini printable, the exact scale numbers, and the commercial-license point that matters if you sell your prints.

Generate the figure: text prompt vs. reference photo

You have two ways in. Text-to-3D is best when the character only exists on your character sheet — you describe it in words. Image-to-3D is best when you already have a single, clear picture (your own art, a portrait render, a sculpt photo) — the tool reconstructs geometry from that one image.

For text, structure the prompt as one sentence describing one figure: race + class + build, then pose, then gear and weapon, then base. Example: "a single dwarf cleric standing upright, full plate armor, holding a warhammer at his side, round shield on his back, bald with a thick braided beard, on a small round base, miniature figurine." Naming the base and the word "miniature" nudges the model toward a self-contained, printable shape rather than a floating bust.

For a photo, use ONE object on a plain, uncluttered background, evenly lit, shot roughly from the front at chest height. Avoid busy backgrounds, multiple figures, or extreme angles — the AI only sees what the image shows, so the back of the figure is inferred and may be softer than the front. If detail on one side matters, generate from the cleanest three-quarter view you have. In HIBR 3D both modes live in the same studio: a photo/text toggle, with text-to-3D and image-to-3D both producing a mesh you can export to STL.

Prompt tips that keep a mini actually printable

AI sculpts what looks good on screen, not what survives a print bed. The most common failures on minis are thin, unsupported elements and fused-together limbs — so steer the generation toward sturdier geometry from the start.

Favor a single figure in a stable, grounded pose. Both feet planted (or one foot plus a planted weapon/staff) gives the printer something to anchor. Avoid prompting for mid-leap, mid-spin, or wildly outstretched poses where an arm or cape becomes a fragile cantilever. Be cautious with the classic detail-killers: loose flowing hair, feathered wings, spindly spear shafts, billowing capes, and outstretched fingers. These render beautifully and then snap at 32mm. If your character has them, expect to either thicken them in a mesh tool afterward, or accept they'll need careful supports.

Keep weapons close to the body in the prompt ("sword resting at side," "staff held vertical and grounded") rather than "raised overhead" — a horizontal blade sticking straight out is the single most-broken feature on printed minis. You're not limited to what the AI gives you: it's a base sculpt. You can scale, and you can thicken or reposition fragile parts in your own slicer or mesh editor before printing.

Export a clean STL and make it watertight

For 3D printing you want STL specifically (GLB and OBJ are for games and AR). Before you slice, the mesh needs to be watertight — a single closed body with no holes or stray floating fragments. AI-generated meshes often arrive with tiny gaps, internal pockets, or a few disconnected specks, and a slicer will either error or silently produce a hollow shell on those.

If you're using a generic AI mesh, run it through a repair step in Blender (3D Print Toolbox add-on), Meshmixer ("Inspector" → auto-repair), or Microsoft 3D Builder before slicing — check that it reports zero non-manifold edges and one shell. In HIBR 3D this is built in: Quick repair (fast cleanup that welds the mesh and fills holes) or Deep repair, which voxel-remeshes the model into a guaranteed watertight single-body STL. Deep repair is the safer choice for a figure you intend to print, because it eliminates the floating-fragment and internal-hole problems in one pass rather than you hunting for them manually.

Whichever route you take, do a final sanity check: one solid body, no obvious holes at the seams, and a flat-ish underside so it sits on the plate. A clean mesh here saves you a failed print later.

Scale to 28-32mm and choose your print scale

D&D and most modern tabletop minis are sized by "heroic" scale, measured to the eyes, not the top of the head. The common targets:

- 28mm heroic: the long-standing tabletop standard, compatible with most older ranges. - 32mm heroic: what most current ranges (and a lot of fantasy lines) actually use today — slightly chunkier, easier to print and paint.

In your slicer, import the STL and set the overall height. A practical rule for a standing humanoid: set the model height (base of feet to top of head) to roughly 32-36mm to land near 28-32mm at the eyes, because the head sits below the crown. If your character is wearing a tall helm or has horns, measure to the eyes and let the spikes run taller. For larger creatures, scale up proportionally — a Large creature occupies a 50mm base and is often printed around 1.6-2x a Medium mini. Lock aspect ratio (uniform scaling) so you don't distort the figure. Print one test at your chosen height before committing a batch; it's the cheapest way to catch a mini that came out too spindly to survive cleanup.

Print it: resin for detail, plus supports and slicing

For minis, resin (MSLA/LCD) is the right tool. It resolves the fine detail — faces, chainmail, sculpted folds — that FDM smears at this size. FDM can work for terrain and chunky 28mm+ pieces, but at miniature scale resin wins on crispness. (See our resin-vs-FDM guide for the full trade-off on cost, mess, and safety.)

The AI gives you the mesh; you own the slicing. In your resin slicer (Lychee, CHITUBOX, or your printer's native app): orient the figure tilted 30-45 degrees and lifted off the plate so resin drains and supports land on hidden surfaces, not the face. Auto-generate supports (medium density is a sane default for a 32mm mini), then manually add a few to outstretched arms, weapons, and any overhang the auto-pass missed — this is exactly where the fragile parts you watched for in the prompt need help. Typical settings: 0.05mm layer height for a good detail/speed balance (0.03mm for showpieces), with exposure tuned to your specific resin and printer via a calibration test, not a guessed number.

After printing, follow the standard resin workflow: wash in IPA and let it dry, then remove the supports while the print is still slightly flexible — before the final cure — because fully cured resin turns brittle and tends to snap detail off along with the supports. Once supports are off and any marks are cleaned up, UV-cure the figure fully. The whole loop — generate, repair, scale, support, slice, print — is repeatable, so iterate the prompt if the first figure's pose or detail didn't come out the way you wanted.

Selling your minis: the commercial-license point

If you print minis to sell — on Etsy, at a con, or as a Patreon STL drop — usage rights are not a footnote, they're the whole business. Many AI 3D tools and most commercial mini ranges restrict resale, and some free or research-licensed models forbid commercial use entirely. Always check the license on whatever generator or STL you use before you list a product.

HIBR 3D includes a full commercial license on every plan (Spark $19/mo, Pro $49/mo, Studio $99/mo; annual is two months free) — what you generate is yours to print and sell. That covers the AI-generated geometry. Two things still sit with you: don't generate trademarked or copyrighted characters (a named character from a game or film is someone else's IP regardless of which tool drew it — and every prompt and uploaded image is moderated before anything generates, so disallowed content won't render), and remember the license covers the model HIBR creates, not third-party reference photos you didn't have the rights to upload.

Practically: build your sellable line from original characters and your own descriptions, keep the generation prompt and date on file as a provenance record, and you have a clean, license-clear catalog of minis to print on demand.

FAQ

More guides